LONG-TERM PAVEMENT PERFORMANCE 

Information Management System 

Pavement Performance Database User Reference Guide 

 

 

 

U.S. Department of Transportation 

Federal Highway Administration 

Research, Development, and Technology 

Turner-Fairbank Highway Research Center 

6300 Georgetown Pike 

McLean, VA 22101-2296 
FOREWORD 

This document provides information to aid in understanding and using the Long-Term Pavement 

Performance (LTPP) program pavement performance database. This document provides an 

introduction to the structure of the LTPP program, the relational structure of the LTPP database, 

a description of the location of various data elements, contents of the data tables, tips on efficient 

means of manipulating data for specific types of investigations, and examples of Structured 

Query Language (SQL) scripts that can be used to build user-defined custom extractions. 

The LTPP program is an ongoing and active program. To obtain current information and access 

to other technical references, LTPP data users should visit the LTPP Web site at

http://www.tfhrc.gov/pavement/ltpp/ltpp.htm. LTPP data requests, technical questions, and data 

user feedback can be submitted to LTPP customer service via e-mail at ltppinfo@fhwa.dot.gov. 

 

 

 T. Paul Teng, P.E. 

Director, Office of Infrastructure 

 Research and Development 

NOTICE 

This document is distributed under the sponsorship of the U.S. Department of Transportation in 

the interest of information exchange. The U.S. Government assumes no liability for its contents 

or use thereof. This report does not constitute a standard, specification, or regulation. 

The U.S. Government does not endorse products or manufacturers. Trade and manufacturers’ 

names appear in this report only because they are considered essential to the object of the 

document. 
 Technical Report Documentation Page 

1. Report No. 

FHWA-RD-03-088 

2. Government Accession No. 3. Recipient’s Catalog No. 

5. Report Date 

November 2003 

4. Title and Subtitle 

LONG-TERM PAVEMENT PERFORMANCE

INFORMATION MANAGEMENT SYSTEM 

PAVEMENT PERFORMANCE DATABASE USER GUIDE 6. Performing Organization Code

7. Author(s) 

Gary E. Elkins, Peter Schmalzer, Travis Thompson, and Amy 

Simpson 

8. Performing Organization Report No. 

9. Performing Organization Name and Address 10. Work Unit No. (TRAIS) 

MACTEC Engineering and Consulting, Inc. 

12104 Indian Creek Court, Suite A 

Beltsville, MD 20705-1242 

11. Contract or Grant No. 

DTFH61-02-C-00007 

13. Type of Report and Period Covered 

Final Report, August 2002– 

June 2003 

12. Sponsoring Agency Name and Address 

Office of Infrastructure Research and Development 

Federal Highway Administration 

6300 Georgetown Pike 

McLean, VA 22101-2296 

14. Sponsoring Agency Code

15. Supplementary Notes 

Contracting Officer’s Technical Representative (COTR): Aramis Lopez, Jr., HRDI-13 

16. Abstract 

This document provides information to aid in understanding and using the Long-Term Pavement 

Performance (LTPP) program pavement performance database. This document provides an 

introduction to the structure of the LTPP program, the relational structure of the LTPP database, a 

description of the location of various data elements, contents of the data table, tips on efficient 

means of manipulating data for specific types of investigations, how to obtain data, and example 

Structured Query Language (SQL) scripts that can be used to build user-defined custom

extractions. 

17. Key Words 

Asphalt concrete, continuously reinforced concrete 

pavement, database, database user guide, deflection 

measurements, dynamic load measurement, general 

pavement studies, jointed plain concrete pavement, jointed 

reinforced concrete pavement, LTPP, pavement distress, 

pavement material properties, pavement performance, 

pavement profile, portland cement concrete, seasonal 

variations, specific pavement studies, traffic load. 

18. Distribution Statement 

No restrictions. This document is 

available to the public through the 

National Technical Information 

Service, Springfield, VA 22161. 

19. Security Classif. (of this report)

Unclassified

20. Security Classif. (of this page)

Unclassified

21. No. of Pages 

 169 

22. Price 

Form DOT F 1700.7 (8-72) Reproduction of completed page authorized
ii

SI* (MODERN METRIC) CONVERSION FACTORS 

APPROXIMATE CONVERSIONS TO SI UNITS

Symbol When You Know Multiply By To Find Symbol 

LENGTH

in inches 25.4 millimeters mm 

ft feet 0.305 meters m

yd yards 0.914 meters m

mi miles 1.61 kilometers km 

AREA

in2 square inches 645.2 square millimeters mm2

ft2 square feet 0.093 square meters m2

yd2 square yard 0.836 square meters m2

ac acres 0.405 hectares ha

mi2 square miles 2.59 square kilometers km2

VOLUME 

fl oz fluid ounces 29.57 milliliters mL

gal gallons 3.785 liters L

ft3 cubic feet 0.028 cubic meters m3 

yd3 cubic yards 0.765 cubic meters m3 

NOTE: volumes greater than 1000 L shall be shown in m3

MASS oz ounces 28.35 grams g

lb pounds 0.454 kilograms kg

T short tons (2000 lb) 0.907 megagrams (or "metric ton") Mg (or "t")

TEMPERATURE (exact degrees) o

F Fahrenheit 5 (F-32)/9 Celsius oC 

or (F-32)/1.8 

ILLUMINATION

fc foot-candles 10.76 lux lx 

fl foot-Lamberts 3.426 candela/m2 cd/m2

FORCE and PRESSURE or STRESS

lbf poundforce 4.45 newtons N

lbf/in2 poundforce per square inch 6.89 kilopascals kPa 

APPROXIMATE CONVERSIONS FROM SI UNITS

Symbol When You Know Multiply By To Find Symbol 

LENGTH mm millimeters 0.039 inches in

m meters 3.28 feet ft

m meters 1.09 yards yd 

km kilometers 0.621 miles mi 

AREA mm2 square millimeters 0.0016 square inches in2 

m2 square meters 10.764 square feet ft

2 

m2 square meters 1.195 square yards yd2 

ha hectares 2.47 acres ac

km2 square kilometers 0.386 square miles mi

2 

VOLUME mL milliliters 0.034 fluid ounces fl oz 

L liters 0.264 gallons gal 

m3 cubic meters 35.314 cubic feet ft

3 

m3 cubic meters 1.307 cubic yards yd3 

MASS 

g grams 0.035 ounces oz

kg kilograms 2.202 pounds lb

Mg (or "t") megagrams (or "metric ton") 1.103 short tons (2000 lb) T

TEMPERATURE (exact degrees) o

C Celsius 1.8C+32 Fahrenheit oF 

ILLUMINATION

lx lux 0.0929 foot-candles fc

cd/m2 candela/m2 0.2919 foot-Lamberts fl

FORCE and PRESSURE or STRESS

N newtons 0.225 poundforce lbf

kPa kilopascals 0.145 poundforce per square inch lbf/in2

*SI is the symbol for the International System of Units. Appropriate rounding should be made to comply with Section 4 of ASTM E380. 

(Revised March 2003)
TABLE OF CONTENTS 

CHAPTER 1. LTPP PROGRAM OVERVIEW............................................................................. 1 

1.1 BACKGROUND .................................................................................................................. 1 

1.2 OBJECTIVES AND SCOPE OF THE LTPP PROGRAM.................................................. 1 

1.3 TEST SECTION DESIGNATIONS..................................................................................... 2 

1.3.1 General Pavement Studies............................................................................................. 3 

1.3.2 Specific Pavement Studies............................................................................................. 3 

1.4 TEST SECTION LAYOUT.................................................................................................. 5 

1.5 REFERENCE MATERIALS................................................................................................ 6 

CHAPTER 2. INTRODUCTION TO THE PAVEMENT PERFORMANCE DATABASE ........ 7 

2.1 RELATIONAL DATABASES AND STRUCTURED QUERY LANGUAGE.................. 7 

2.2 QUALITY CONTROL......................................................................................................... 8 

2.3 GPS AND SPS SECTION IDENTIFICATION................................................................... 9 

2.4 MODULES ......................................................................................................................... 10 

CHAPTER 3. ADMINISTRATION MODULE........................................................................... 13 

3.1 EXPERIMENT_SECTION TABLE .................................................................................. 13 

3.2 LTPPDD Table ................................................................................................................... 15 

3.3 CODES ............................................................................................................................... 16 

3.4 COMMENTS_GENERAL ................................................................................................. 17 

3.5 REGIONS ........................................................................................................................... 17 

CHAPTER 4. AUTOMATED WEATHER STATION MODULE ............................................. 19 

4.1 IMPORTANT FIELDS....................................................................................................... 19 

4.2 AWS TABLES.................................................................................................................... 19 

CHAPTER 5. CLIMATE MODULE ........................................................................................... 21 

5.1 IMPORTANT FIELDS....................................................................................................... 21 

5.2 CLM TABLES.................................................................................................................... 21 

5.2.1 Online CLM Tables ..................................................................................................... 21 

5.2.2 Offline CLM Tables..................................................................................................... 22 

5.2.3 Tables in Other Modules.............................................................................................. 23 

5.3 CALCULATIONS.............................................................................................................. 23 

5.3.1 VWS Calculations........................................................................................................ 23 

5.3.2 Freezing Index ............................................................................................................. 24 

CHAPTER 6. DYNAMIC LOAD RESPONSE MODULE......................................................... 25 

6.1 IMPORTANT FIELDS....................................................................................................... 25 

6.2 DLR TABLES .................................................................................................................... 26 

CHAPTER 7. INVENTORY MODULE...................................................................................... 29 

7.1 INV TABLES ..................................................................................................................... 29 

CHAPTER 8. MAINTENANCE AND REHABILITATION MODULES ................................. 33 

8.1 IMPORTANT FIELDS....................................................................................................... 33 

8.2 MNT TABLES.................................................................................................................... 36 

8.3 RHB TABLES .................................................................................................................... 37 

8.3.1 Nonrehabilitation-Specific Tables............................................................................... 37 

8.3.2 RHB Tables for AC Overlays...................................................................................... 37 

8.3.3 RHB Tables for PCC Overlays.................................................................................... 40 

8.3.4 Non-Overlay RHB Tables............................................................................................ 41 

iii
8.4 TABLES IN OTHER MODULES...................................................................................... 42 

CHAPTER 9. PAVEMENT MONITORING MODULE............................................................. 43 

9.1 PHOTOGRAPHIC AND MANUAL DISTRESS.............................................................. 43 

9.1.1 MON_DIS Tables........................................................................................................ 43 

9.2 TRANSVERSE PROFILE DISTORTION ........................................................................ 45 

9.2.1 MON_T_PROF Tables................................................................................................ 47 

9.2.2 MON_RUT_DEPTH_POINT Table ........................................................................... 48 

9.3 LONGITUDINAL PROFILE............................................................................................. 48 

9.3.1 MON_PROFILE Tables.............................................................................................. 49 

9.4 DEFLECTION MEASUREMENTS .................................................................................. 49 

9.4.1 MON_DEFL Tables..................................................................................................... 49 

9.5 BACKCALCULATION TABLES..................................................................................... 51 

9.6 FRICTION.......................................................................................................................... 53 

9.7 DRAINAGE........................................................................................................................ 53 

CHAPTER 10. SEASONAL MONITORING PROGRAM MODULE....................................... 55 

10.1 DATA TABLES ............................................................................................................... 55 

10.1.1 Ambient Temperature and Precipitation.................................................................... 55 

10.1.2 Subsurface Temperature ............................................................................................ 56 

10.1.3 Subsurface Moisture Content..................................................................................... 56 

10.1.4 Frost Penetration ........................................................................................................ 58 

10.1.5 Depth to Water Table................................................................................................. 59 

10.1.6 Surface Elevation Data .............................................................................................. 59 

10.1.7 Joint Opening and Faulting........................................................................................ 60 

10.1.8 Additional SMP Tables.............................................................................................. 60 

CHAPTER 11. SPECIFIC PAVEMENT STUDIES MODULE.................................................. 63 

11.1 IMPORTANT FIELDS..................................................................................................... 63 

11.2 GENERAL SPS TABLES ................................................................................................ 64 

11.3 NUMBERED TABLES COMMON TO MULTIPLE EXPERIMENTS......................... 65 

11.4 TABLES SPECIFIC TO INDIVIDUAL EXPERIMENTS.............................................. 68 

CHAPTER 12. TRAFFIC MODULE........................................................................................... 73 

12.1 IMPORTANT FIELDS..................................................................................................... 73 

12.2 TRF TABLES ................................................................................................................... 74 

CHAPTER 13. MATERIALS TESTING MODULE................................................................... 77 

13.1 BACKGROUND .............................................................................................................. 77 

13.2 MATERIALS TEST TYPES............................................................................................ 77 

13.3 IMPORTANT FIELDS..................................................................................................... 80 

13.4 UNDERSTANDING THE MATERIALS TESTING DATA STRUCTURES ............... 81 

13.4.1 Test Results Tables.................................................................................................... 81 

13.4.2 Sampling Information Tables .................................................................................... 97 

13.4.3 Layer Tables............................................................................................................. 101 

13.4.4 SPS Complications .................................................................................................. 103 

13.5 KEY TABLES ................................................................................................................ 105 

13.5.1 TST_L05B ............................................................................................................... 105 

CHAPTER 14. OBTAINING LTPP DATA............................................................................... 108 

14.1 DATA RELEASE POLICY ........................................................................................... 108 

14.2 OBTAINING LTPP DATA............................................................................................ 108 

iv
14.2.1 Standard Data Release ............................................................................................. 108 

14.2.2 Custom Extractions.................................................................................................. 109 

14.2.3 DataPave .................................................................................................................. 109 

14.2.4 LTPP Data Over the Internet ................................................................................... 110 

APPENDIX A. LTPP OPERATIONS REFERENCE DOCUMENTS...................................... 112 

A.1 GENERAL....................................................................................................................... 112 

A.2 PAVEMENT MONITORING ......................................................................................... 112 

A.3 MATERIALS SAMPLING AND TESTING.................................................................. 113 

A.4 SEASONAL MONITORING PROGRAM ..................................................................... 114 

A.5 GPS EXPERIMENTS...................................................................................................... 114 

A.6 SPS EXPERIMENTS ...................................................................................................... 114 

A.7 TRAFFIC DATA............................................................................................................. 118 

A.8 CLIMATIC DATA .......................................................................................................... 119 

A.9 DYNAMIC LOAD RESPONSE DATA ......................................................................... 119 

A.10 SITE REPORTS............................................................................................................. 119 

A.10.1 SPS Materials Sampling, Field Testing, and Laboratory Testing Plans................. 119 

A.10.2 SPS Construction Reports....................................................................................... 125 

A.10.3 SMP Installation Reports........................................................................................ 134 

APPENDIX B. EXPERIMENT DEFINITIONS........................................................................ 140 

B.1 GPS EXPERIMENTS...................................................................................................... 140 

B.1.1 GPS-1: Asphalt Concrete on Granular Base ............................................................. 140 

B.1.2 GPS-2: Asphalt Concrete on Bound Base................................................................. 140 

B.1.3 GPS-3: Jointed Plain Concrete Pavement (JPCP)..................................................... 140 

B.1.4 GPS-4: Jointed Reinforced Concrete Pavement (JRCP)........................................... 140 

B.1.5 GPS-5: Continuously Reinforced Concrete Pavement (CRCP)................................ 141 

B.1.6 GPS-6: Asphalt Concrete Overlay of Asphalt Concrete Pavement .......................... 141 

B.1.7 GPS-7: Rehabilitated Portland Cement Concrete Pavement..................................... 141 

B.1.8 GPS-9: Unbound PCC Overlays of PCC .................................................................. 142 

B.2 SPS EXPERIMENTS....................................................................................................... 142 

B.2.1 SPS-1: Structural Factors for Flexible Pavements.................................................... 142 

B.2.2 SPS-2: Structural Factors for Rigid Pavements ........................................................ 142 

B.2.3 SPS-3: Preventive Maintenance Effectiveness of Flexible Pavements..................... 143 

B.2.4 SPS-4: Preventive Maintenance Effectiveness of Rigid Pavements......................... 143 

B.2.5 SPS-5: Rehabilitation of Asphalt Concrete Pavements............................................. 143 

B.2.6 SPS-6: Rehabilitation of Jointed Portland Cement Concrete (JPCC) Pavements..... 143 

B.2.7 SPS-7: Bonded Concrete Overlays of Concrete Pavements..................................... 143 

B.2.8 SPS-8: Environmental Effects in the Absence of Heavy Loads............................... 144 

B.2.9 SPS-9: Validation of SHRP Asphalt Specifications and Mix Design....................... 144 

APPENDIX C. DATA EXTRACTION EXAMPLES ............................................................... 146 

C.1 SMP DATA...................................................................................................................... 146 

C.1.1 Ambient Temperature and Precipitation ................................................................... 146 

C.1.2 Subsurface Temperatures.......................................................................................... 147 

C.1.3 Subsurface Moisture.................................................................................................. 147 

C.1.4 Electrical Resistance and Resistivity......................................................................... 148 

C.2 BACKCALCULATION .................................................................................................. 151 

C.2.1 MON_DEFL Database Tables.................................................................................. 151 

v
C.2.2 Temperature Tables................................................................................................... 152 

C.2.3 Deflection Tables...................................................................................................... 152 

C.2.4 Layer Information Tables.......................................................................................... 155 

C.2.5 Laboratory Materials Testing Data ........................................................................... 156 

INDEX........................................................................................................................................ 160 

vi
LIST OF FIGURES 

Figure 1. Layout of a generic GPS test section ...................................................................5 

Figure 2. Example layout of a generic SPS project.............................................................5 

Figure 3. Relational structure of data stored in the DLR module......................................26 

Figure 4. Illustration of how transverse profile measurements are normalized to 

 lane edges...........................................................................................................45 

Figure 5. Illustration of LTPP transverse pavement distortion indices based 

on 1.8-m (6-ft) straightedge reference. Distortion indices are computed for each 

half of the lane, including depth, offset to point of maximum depth, and 

 depression width ................................................................................................46 

Figure 6. Illustration of LTPP transverse pavement distortion indices based on 

lane-width wireline reference. Distortion indices are computed for each 

half of the lane, including depth, offset, and depression width..........................47 

Figure 7. Relational structure among tables in the MON_T_PROF module ....................48 

Figure 8. Structural relationship between tables used to store FWD data.........................50 

Figure 9. Illustration of relationships among TST_AC07* tables ....................................84 

Figure 10. Illustration of relationships among TST_UG07_SS07* tables..........................96 

Figure 11. Plan view of hypothetical SPS project (not to scale).......................................104 

Figure 12. Cross-sectional view of hypothetical SPS project ...........................................104 

LIST OF TABLES 

Table 1. List of GPS experiments......................................................................................4 

Table 2. List of SPS experiments by category ...................................................................4 

Table 3. IMP_TYPE and expected location of data in MNT and RHB tables ................34 

Table 4. FHWA 13-bin vehicle classification system......................................................74 

Table 5. Materials testing designations and protocols.....................................................78 

vii
LIST OF ACRONYMS AND ABBREVIATIONS 

AADT Annual average daily traffic 

AASHO American Association of State Highway Officials 

AASHTO American Association of State Highway and Transportation Officials 

AC Asphalt concrete 

ASTM American Society for Testing and Materials 

ATB Asphalt-treated base 

AVC Automated vehicle classification 

AWS Automated weather station 

BBR Bending-beam rheometer 

CCC Canadian Climatic Center 

CRCP Continuously reinforced concrete pavement 

DLR Dynamic load response 

DSR Dynamic shear rheometer 

DT Direct tension 

ESAL Equivalent single-axle load 

FHWA Federal Highway Administration 

FIPS Federal Information Processing Standards 

FWD Falling-weight deflectometer 

GPS General Pavement Studies 

HMA Hot-mix asphalt 

HMAC Hot-mix asphalt concrete 

IRI International Roughness Index 

JPCC Jointed portland cement concrete 

JPCP Jointed plain concrete pavement 

JRCP Jointed reinforced concrete pavement 

LEF Load equivalency factor 

LTPP Long-Term Pavement Performance 

LVDT Linear variable differential transformer 

NCDC National Climatic Data Center 

NCHRP National Cooperative Highway Research Program 

NRC National Research Council 

OWS Operating weather stations 

PADIAS Pavement Distress Analysis System

PATB Permeable asphalt-treated base 

PCC Portland cement concrete 

PMA Plant-mixed asphalt 

PVR Potential vertical rise 

QC Quality control 

RDBMS Relational database management system

RMSVA Root mean square vertical acceleration 

SAMI Stress-absorbing membrane interlayers 

SHRP Strategic Highway Research Program 

SI International System of Units 

viii
CHAPTER 1. LTPP PROGRAM OVERVIEW

1.1 BACKGROUND 

During the early 1980s, the Transportation Research Board (TRB) of the National Research 

Council, under the sponsorship of the Federal Highway Administration (FHWA) and with the 

cooperation of the American Association of State Highway and Transportation Officials 

(AASHTO), undertook a Strategic Transportation Research Study (STRS) of the deterioration of 

the Nation’s highway and bridge infrastructure system. The study recommended that a Strategic 

Highway Research Program (SHRP) be initiated to focus research and development activities on 

improving highway transportation. The study report, published in 1984 as TRB Special Report 

202, America’s Highways, Accelerating the Search for Innovation, recommended six strategic 

research areas. The Long-Term Pavement Performance (LTPP) program was one of these areas. 

During 1985 and 1986, independent contractors developed detailed research plans for SHRP. The 

detailed research plans were published in May 1986 as a TRB report entitled Strategic Highway 

Research Program–Research Plans. 

The LTPP program was envisioned as a comprehensive program to satisfy a wide range of 

pavement information needs. It draws on technical knowledge of pavements currently available 

and seeks to develop models that will better explain how pavements perform. It also seeks to gain 

knowledge of the specific effects on pavement performance of various design features, traffic and 

environment, materials, construction quality, and maintenance practices. As sufficient data become

available, analyses are conducted to provide better performance prediction models for use in 

pavement design and management; better understanding of the effects of many variables on 

pavement performance; and new techniques for pavement design, construction, and rehabilitation. 

The strategy behind the LTPP program represents a significant shift in the traditional research 

approach. Traditionally, pavement performance research was divided into specific topics of limited 

scope and duration, which started with data collection and ended with recommendations based on 

analysis of the collected data. To overcome some of the challenges posed by the study of pavement 

behavior in short-term efforts, the LTPP program was established as a long-term national effort. 

Under the LTPP paradigm, data collection is conducted in advance of the development of many 

specific data analysis objectives. Since individuals not involved in data collection operations 

conduct many of the important data analyses, the LTPP program has invested in the development 

of a publicly accessible database and database use tools. 

1.2 OBJECTIVES AND SCOPE OF THE LTPP PROGRAM 

The overall objective of the LTPP program is to assess long-term performance of pavements under 

various loading and environmental conditions over a period of 20 years. The specific objectives for 

the LTPP program are: 

1. Evaluate existing design methods. 

2. Develop improved design methodologies and strategies for the rehabilitation of existing 

pavements. 

3. Develop improved design equations for new and reconstructed pavements. 

1 
4. Determine the effects of: (a) loading, (b) environment, (c) material properties and 

variability, (d) construction quality, and (e) maintenance levels on pavement distress and 

performance. 

5. Determine the effects of specific design features on pavement performance. 

6. Establish a national long-term pavement database to support SHRP objectives and future 

needs. 

The LTPP program is a study of the behavior of in-service pavement sections. These pavement 

sections have been constructed using highway agency specifications and contractors, and subjected 

to real-life traffic loading. These in-service pavement sections are classified in the LTPP program

as General Pavement Studies (GPS) and Specific Pavement Studies (SPS). GPS consist of a series 

of studies on nearly 800 in-service pavement test sections throughout the United States and 

Canada. SPS are intensive studies of specific variables involving new construction, maintenance 

treatments, and rehabilitation activities. 

1.3 TEST SECTION DESIGNATIONS 

To provide a logical basis for test section designations, a broad-based experimental approach has 

been used. Test sections are classified as GPS or SPS. The fundamental difference between these 

two classifications is that at the start of the LTPP program, the GPS test sections are existing 

pavements and the SPS projects are sites where multiple test sections of differing experimental 

treatment factors are constructed. When a GPS or SPS test section is rehabilitated, it can be 

assigned to a GPS rehabilitation designation. 

While the LTPP test section classification methodology is based on experimental concepts, data 

users are encouraged to develop their own classification methods to meet specific analytical 

objectives. For example, the SPS-1 experiment is designed to extend the findings from the GPS-1 

and -2 studies. 

In the published literature, the LTPP projects are designated by experiment designs. A factorial 

combination approach has been used for the development of the experiment design designation of 

each GPS and SPS experiment. This approach requires the identification of significant pavement 

and environmental/loading factors considered to have an influence on pavement performance. 

Pavement factors include such variables as layer thickness, base type, base thickness, joint spacing, 

and percent steel reinforcement, which are varied as appropriate for the pavement type being 

studied. Environmental/loading factors include moisture (wet/dry), temperature (freeze/no-freeze), 

subgrade classification (fine/coarse grained), and traffic loading rate (low/high). 

The combination of these selected factors form an experimental factorial that is used as the 

sampling basis for test sections included in each study. Within GPS, these factorials are more 

properly considered as sampling templates used in the selection of pavement structures included in 

the studies. Since GPS consists mostly of pavements that were constructed and in service prior to

the start of the LTPP program, it is impossible to find pavements with all of the combinations 

defined within the factorial. SPS is a more controlled experiment requiring construction of the 

specified pavement structures. While the SPS experimental factorials are closer to a classical 

experiment design, between-site construction deviations should be considered in many types of 

statistical analyses. 

2 
1.3.1 General Pavement Studies 

The GPS program is a series of studies on selected in-service pavements structured to develop a 

comprehensive national pavement performance database. These studies are restricted to pavements 

that incorporate materials and designs representing good engineering practices and that have 

strategic future importance. Because of the nationwide thrust of the program, the studies are 

limited to pavement structures in common use across the United States. 

The GPS test sections are located on pavement structures constructed up to 15 years prior to the 

start of the LTPP program. Although detailed research-level measurements on these pavements 

during the early years of their lives are not available, the GPS test sections offer the potential for 

development of earlier results than those possible from newly constructed test sections. As the SPS 

test sections are rehabilitated, they are reclassified into the GPS experiment designations. Table 1 

provides a list of the titles of each of the experiments. A more comprehensive definition is 

provided in appendix B. 

It should be noted that the proposed GPS-8 study of bonded portland cement concrete (PCC) 

overlays on PCC pavements was not pursued because of lack of an adequate number of nominated 

in-service projects. An SPS study on bonded PCC overlays, SPS-7, was formulated to address this 

type of rehabilitation alternative. 

1.3.2 Specific Pavement Studies 

The SPS program is a long-term study of specially constructed, maintained, or rehabilitated 

pavement sections incorporating a controlled set of experiment design and construction features. 

The objective of SPS is to provide a more detailed and complete base of data to extend and refine 

the results obtained from the GPS studies. The SPS program incorporates nine studies grouped into 

the five categories as illustrated by table 2. Appendix B provides a more complete definition of 

each of the experiments. 

Essentially, the SPS program involves monitoring newly constructed sections or existing pavement 

sections subjected to maintenance or rehabilitation treatments. Each SPS experiment requires 

construction of multiple test sections at each site. The number of test sections may range from two 

for SPS-8 to twelve for SPS-1 and -2. In addition, a highway agency may construct supplemental 

test sections on an SPS site to investigate other factors of interest to the agency. The following 

definitions apply only to the core sections within each experiment. The supplemental sections that 

may have been constructed by a highway agency are based on the respective agency’s research 

interests and are typically not consistent among highway agencies. 

3 
Table 1. List of GPS experiments. 

Experiment Experiment Title

GPS-1 Asphalt Concrete (AC) Pavement on Granular Base 

GPS-2 AC Pavement on Bound Base 

GPS-3 Jointed Plain Concrete Pavement (JPCP) 

GPS-4 Jointed Reinforced Concrete Pavement (JRCP) 

GPS-5 Continuously Reinforced Concrete Pavement (CRCP) 

GPS-6A Existing AC Overlay of AC Pavement (existing at the start of the program) 

GPS-6B AC Overlay Using Conventional Asphalt of AC Pavement–No Milling 

GPS-6C AC Overlay Using Modified Asphalt of AC Pavement–No Milling 

GPS-6D AC Overlay on Previously Overlaid AC Pavement Using Conventional 

Asphalt 

GPS-6S AC Overlay of Milled AC Pavement Using Conventional or Modified 

Asphalt 

GPS-7A Existing AC Overlay on PCC Pavement 

GPS-7B AC Overlay Using Conventional Asphalt on PCC Pavement 

GPS-7C AC Overlay Using Modified Asphalt on PCC Pavement 

GPS-7D AC Overlay on Previously Overlaid PCC Pavement Using Conventional 

Asphalt 

GPS-7F AC Overlay Using Conventional or Modified Asphalt on Fractured PCC 

Pavement 

GPS-7R Concrete Pavement Restoration Treatments With No Overlay 

GPS-7S Second AC Overlay, Which Includes Milling or Geotextile Application, on 

PCC Pavement With Previous AC Overlay 

GPS-9 Unbonded PCC Overlay on PCC Pavement 

Table 2. List of SPS experiments by category. 

Category Experiment Title

Pavement SPS-1 Strategic Study of Structural Factors for Flexible Pavements 

Structural 

Factors 

SPS-2 Strategic Study of Structural Factors for Rigid Pavements 

Pavement SPS-3 Preventive Maintenance Effectiveness of Flexible Pavements

Maintenance SPS-4 Preventive Maintenance Effectiveness of Rigid Pavements 

SPS-5 Rehabilitation of AC Pavements 

SPS-6 Rehabilitation of Jointed Portland Cement Concrete (JPCC) 

Pavements 

Pavement 

Rehabilitation 

SPS-7 Bonded PCC Overlays of Concrete Pavements 

Environmental 

Effects 

SPS-8 Study of Environmental Effects in the Absence of Heavy 

Loads 

SPS-9P Validation and Refinements of Superpave®Asphalt 

Specifications and Mix Design Process 

Asphalt 

Aggregate 

Mixture 

Specifications 

SPS-9A Superpave Asphalt Binder Study 

4 
1.4 TEST SECTION LAYOUT 

Generally, each GPS and SPS test section consists of a 152-meter (m) (500-foot (ft)) monitoring 

portion with a 15.2-m (50-ft) materials sampling section at each end. On GPS test sections, a 

maintenance control zone, extending 152 m (500 ft) in front of and 76 m (250 ft) beyond the limits 

of the monitoring section, has been established around each test section as illustrated in figure 1. 

Since SPS projects consist of multiple test sections constructed for a single project, the 

maintenance control zone is extended to cover groups of adjoining sections as illustrated in figure 

2. 

Figure 1. Layout of a generic GPS test section. 

152 m

(500 ft)

152 m

(500 ft) 

76 m

(250 ft)

Maintenance Traffic

Control Zone 

Maintenance 

Control Zone Test Section

Test Sections

Maintenance Control Zones

152 m 152 m

Transition Zones

Test Sections

Maintenance Control Zones

Transition Zones

152 m

(500 ft)

152 m

(500 ft)

76 m

(250 ft)

(250 ft)

152 m

(500 ft)

152 m

(500 ft)

Figure 2. Example layout of a generic SPS project. 

The exceptions to the 152-m (500-ft-) long test section include the crack-and-seat test sections in 

the SPS-6 experiment and some agency supplemental sections constructed on SPS projects. The 

crack-and-seat sections on SPS-6 are 305-m (1,000-ft) long, while agency supplemental sections 

have been constructed both shorter and longer than the 152-m (500-ft) standard section. 

The LTPP program uses a test section and project station location convention. The test section 

station convention is based on the staring point of the monitoring portion of the section being 

assigned a station of 0. The longitudinal locations in the direction of traffic are assigned positive 

stations. When the LTPP program was started, longitudinal locations were designated using U.S. 

customary units of 100-ft (30.5-m) stations. However, in the database, longitudinal locations are 

converted to metric meter stations. Thus, the original 5+00 test section station painted on the 

5 
pavement surface is represented as 152 m in the POINT_LOC field in the database. (Note: For data 

users reviewing film or video of LTPP test sections, painted white cross markings are located at 

30.5-m (100-ft) intervals.) The project station location convention applies to SPS project sites 

where more than one test section is located. 

LTPP Database 

Tip!

The database has not been completely converted to metric units. Some of the 

modules are in the International System of Units (SI) and some are still in the 

U.S. customary units. The units for every data element are stored in the LTPP 

data dictionary (LTPPDD) table. Units should be checked to ensure that 

calculations are performed with consistent units. 

A project station location convention is used where multiple test sections are located on the same

SPS project site. The project station convention starts with station 0 assigned to the first test 

section located at the project site in the direction of travel. The SECTION_START and 

SECTION_END fields in the SPS_PROJECT_STATIONS table contain project station location 

information. 

LTPP Database 

Tip!

The SPS_PROJECT_STATIONS table can be used as a link table to associate 

both GPS and SPS test sections co-located at an SPS project site. In this table, 

the TEST_SECTION field contains a joined STATE_CODE+SHRP_ID that 

can be used to identify specific test sections. 

The overriding philosophy of sampling and monitoring measurements on LTPP test sections is to 

not permit destructive testing or sampling within the monitoring portion of the section.

1.5 REFERENCE MATERIALS 

A list of LTPP operational documents is presented in appendix A. These documents provide details 

on all of the LTPP data collection activities stored in the LTPP database. 

6 
CHAPTER 2. INTRODUCTION TO THE PAVEMENT 

PERFORMANCE DATABASE 

The pavement performance database was designed to store the majority of the data collected by 

the LTPP program for easy and convenient dissemination and use. The pavement performance 

database is a relational database originally implemented in Oracle® 5 format. As of this writing, 

the production database is implemented in Oracle 9i. To harness the power of relational 

databases to manipulate large amounts of data at a reasonable cost, most users prefer to obtain 

data from the production database in an alternate database format. (See chapter 14 for data 

request procedures.) Currently, the LTPP program is using Microsoft® Access® 2000 as a 

standard format for data releases. This may change in the future. International data users, who do 

not have access to the English-language version of Microsoft Access 2000, may wish to request 

customized extractions in other formats.1

The overall structure of the database is based on the LTPP data collection and processing flow. 

LTPP data are collected and processed by four regional contractors. Each of these contractors is 

responsible for loading and processing the data for test sections in their region into regional 

databases. Each regional database contains data for the test sections in that region (the

breakdown of States and Provinces by region is located in the REGIONS table of the database). 

Data from the regional databases are uploaded to the national database for consolidation and 

release to the public on a 6-month cycle. 

2.1 RELATIONAL DATABASES AND STRUCTURED QUERY LANGUAGE 

The LTPP pavement performance database is a relational database, meaning that it is composed 

of separate, but related, tables of data. The importance of a relational database from a user’s 

viewpoint is that all data are stored in a simple row/column format in tables (rows are sometimes 

referred to as records and columns are sometimes referred to as fields). Each row of data is 

uniquely identified by the values in a primary key column or a combination of columns (most of 

the tables in the LTPP database use multicolumn keys). In addition, relationships exist among the 

tables of the database that are represented by common data values stored in more than one table. 

For example, many data tables contain STATE_CODE and SHRP_ID columns, which are how 

test sections or projects are uniquely identified. These fields can be used to located data for a 

specific test section in many tables. 

One critical characteristic of relational databases is that they are self-describing. This means that 

information about the structure of the database is represented in the same row and column format 

as the data itself. The data dictionary, stored in the LTPPDD table, includes much of this 

information. Users unfamiliar with the database should examine LTPPDD and learn how to use 

it. Alternatively, the LTPP program developed the Table Navigator software that allows a user to 

browse the database structure as a three-tiered representation consisting of tables, fields, and 

codes. Currently, Table Navigator can be obtained as a program running on Microsoft Windows®

platforms. It is planned to migrate this software to an Internet Web platform. 

 

1 As of this writing, LTPP had not established support for non-English language database formats. Please contact 

LTPP customer support for nonstandard data extraction requests. 

7 
Structured Query Language (SQL) is the standard language for controlling and interacting with 

relational databases. It is supported by modern relational database management systems 

(RDBMS’s). For data users, one of the most important features of SQL is its ability to retrieve 

and combine data elements stored in multiple tables based on conditions set by the user. SQL can 

be used to create new tables, called queries, which contain data elements of interest in a specific 

analytical objective. To harness the full power and convenience of the LTPP database, users 

should become familiar with SQL. Some example data extractions using some fundamental SQL 

commands are provided in appendix C of this document. The data extraction examples in 

appendix C require a basic knowledge of SQL. 

 

2.2 QUALITY CONTROL 

For equipment measurements, quality control (QC) procedures include routine calibrations, data

checks during acquisition, and data checks prior to database loading. Large amounts of data are 

supplied on paper forms from many different agencies. QC checks on this information consist of 

reviews of completeness and validity of the provided information. 

Data in the database undergo several levels of data quality checks. The results of these checks 

are recorded in the RECORD_STATUS field. All data tables contain a RECORD_STATUS 

field. There are three major types of QC checks: 

• Level-C Checks: These are checks on required fields to identify critical fields that 

contain a null value. In some cases, these checks are supplanted by non-null restrictions 

placed on critical fields during the table design that prevent a record from being created 

if a value for that field is not entered. 

• Level-D Checks: These are range checks on the validity and reasonableness of values 

entered in a field. For example, the range checks for deflection data from the center 

sensor on a falling-weight deflectometer (FWD) is 5 to 2032 micrometers (μm).

• Level-E Checks: These checks are relational checks between data stored in other fields. 

This category contains a wide range of checks. The common property of these checks is 

that they compare the value in one field of a table to the value in another field that may 

or may not be in the same table. For example, a level-E check is used to see if pavement 

layer temperature gradient data exist for each FWD data set. In addition, level-E checks 

are used to enforce referential integrity between parent and child tables. 

These QC checks are performed sequentially. Level-D checks are applied only to records passing 

level-C checks, and level-E checks are applied only to records passing level-D checks. Record 

statuses of A and B are used for data that either have not undergone QC check processing or 

have not passed the level-C checks. If a record fails a check, its record status remains at the next

lower status. For example, records failing a level-D check have a status of C. Alternatively, the 

record status can be manually upgraded if the record has been examined and has been found to 

be acceptable. 

8 
Records with level-E status can mean any of the following: 

• Records have passed all of the data checks. 

• Records may have failed some data checks; however, they have been manually upgraded 

after inspection and data editing. 

• Records may contain errors that have not been detected by the current data review 

process. 

The QC checks applied to LTPP data are limited. It is not possible to inspect all of the data for 

all types of potential anomalies. As the program evolves and improvements are made to the data 

QC checks, level-E data included in previous releases may be reclassified. 

Records with a status of less than E can be interpreted as: 

• Records have not completed the QC process. 

• Records have completed the QC process, but were left at a lower level of record status 

because they contained a flaw. 

• Records are not currently subjected to the QC process by policy. 

Note: As of this writing, QC checks are not performed on supplemental sections. 

Supplemental sections are sections on an SPS project that are not part of the national 

experiment, but have been designed by the owning agency for their own purposes. The 

LTPP program is currently in the process of developing checks on these very important 

data sets. 

LTPP data users assume the responsibility for conclusions based on interpretation of data 

collected by the LTPP program. Level-E data should not be considered as more reliable than 

non-level-E data. Likewise, non-level-E data should not be considered less reliable than level-E 

data. The record status for non-level-E data can be used as a relative indicator of potential issues 

that might exist for these data. As the LTPP program continues to evolve, users can expect 

changes to be made to LTPP data to improve their use in analyses. 

2.3 GPS AND SPS SECTION IDENTIFICATION 

LTPP test sections fall into one of two categories: General Pavement Studies (GPS) or Specific 

Pavement Studies (SPS). From the database viewpoint, the critical difference between GPS and 

SPS sections stems from the fact that multiple SPS sections are co-located on a single project. 

This co-location allows these sections to share climatic, traffic, and some materials data. Sections 

co-located on an SPS project are identified as sharing a STATE_CODE and PROJECT_ID in the 

SPS_PROJECT_STATIONS table. The TEST_SECTION field in this table contains the actual 

SHRP_ID of the test section. The SPS_PROJECT_STATIONS field also includes information 

about the location of these test sections relative to each other. 

From a data user’s viewpoint, another important difference between GPS and SPS test sections is 

that similar information is stored in different tables. Construction and general information for 

GPS test sections are stored in the INV tables. For example, the road designation and test section 

9 
location coordinates for a GPS section are stored in the INV_ID table. For SPS sections 

classified in maintenance or rehabilitation experiments, location information is stored in the 

INV_ID tables using a project-level ID in the SHRP_ID field that applies to all test sections 

located on the project. Additionally, data about the pavement structure prior to treatment are 

stored in the INV module. Construction information for SPS test sections is stored in the SPS 

tables. Other general information for the new construction SPS experiments is also stored in the 

SPS tables. Location information for these experiments is in the SPS_ID table. 

LTPP Database 

Tip!

The GPS_SPS field in the EXPERIMENT_SECTION table identifies whether 

a section is a GPS or SPS section. The SHRP_ID field for SPS sections is 

“smart”. The first character in SHRP_ID for SPS sections is always a 0 or a 

letter. The second character in SHRP_ID for SPS sections identifies the 

experiment number. Over time, some SPS test sections are reassigned to GPS 

because of a rehabilitation activity; however, they retain the original 

SHRP_ID. However, all sections with a SHRP_ID beginning with a 0 are not 

SPS. A GPS test section in Texas has a SHRP_ID of 0001. Always check the 

GPS_SPS field in EXPERIMENT_SECTION before assuming that a section 

is an SPS section because of its SHRP_ID. 

2.4 MODULES 

The database is divided into modules containing similar sets of tables. With the exception of the 

tables in the Administration module, the first three letters of the table name identify the module 

to which a particular table belongs. The modules are as follows: 

• Administration (ADM): This module contains tables that describe the structure of the 

database and the master test section control table. Key tables in this module are 

LTPPDD, which describes each field in each table; CODES, which describes codes used 

in the database; and EXPERIMENT_SECTION, which is the master control table for the 

test sections. The REGIONS table contains a mapping of States to LTPP operations 

administrative designations. 

• Automated Weather Station (AWS): This module contains data collected by the LTPP 

program from automated weather stations installed on some SPS projects. 

• Climate (CLM): This module contains data collected from offsite weather stations that 

are used to compute a simulated virtual weather station for LTPP test sections or project 

sites. Data in this module are updated at 5-year intervals. 

• Dynamic Load Response (DLR): This module contains dynamic load response 

instrumentation data from SPS test sections located in North Carolina and Ohio. 

• Inventory (INV): This module contains inventory information for all GPS test sections 

and for SPS sections originally classified in maintenance and rehabilitation experiments. 

Tables in this module contain information such as the location of the test section and 

structure information supplied by the owning State or Provincial agency. Since this 

10 
structure information comes from agency project records and not necessarily from actual 

measurements taken at the test sections, the information is generally regarded as suspect 

for use in many types of pavement performance analyses requiring information on the 

actual dimensions of the test section pavement structure. 

• Maintenance (MNT): This module contains information on maintenance-type 

treatments reported by a highway agency that were applied to a test section. Treatments 

included in these tables are thin surface treatments, crack sealing, joint sealing, and 

patching performed on in-service test sections. 

• Monitoring (MON): This module contains pavement performance monitoring data and 

it is the largest module in the database. It can be understood best as a collection of 

submodules by data type: 

o Deflection (MON_DEFL): This submodule contains data from FWD tests. 

o Distress (MON_DIS): This submodule contains distress survey data from both 

manual and film-based surveys. 

o Friction (MON_FRICTION): This submodule contains friction measurements taken 

by participating highway agencies. 

o Profile (MON_PROFILE): This submodule contains longitudinal profile data 

collected by an automated profiler or by manual dipstick measurements. 

o Rut (MON_RUT): This submodule contains rutting data measured using a 1.2-m (4-

ft) straightedge. These data tables are superseded by the rutting indices located within 

the Transverse Profile module. (Note: Straightedge rut measurements were not taken 

on all test sections.)

o Transverse Profile (MON_T_PROF): This submodule contains transverse profile 

data and computed transverse profile distortion indices (rut depth) from manual 

dipstick measurements or the optical Pavement Distress Analysis System (PADIAS) 

method. 

• Rehabilitation (RHB): This module contains information on rehabilitation treatments. A 

key table in this module is RHB_IMP, which identifies the various applied treatments 

that result in changes to CONSTRUCTION_NO. 

• Seasonal Monitoring Program (SMP): This module contains SMP-specific data, such 

as the onsite air temperature and precipitation data, subsurface temperature and moisture 

content data, and frost-related measurements. 

• Specific Pavement Studies (SPS): This module contains SPS-specific general and 

construction information. 

• Traffic (TRF): This module contains traffic load, classification, and volume data. 

• Test (TST): This module contains field and laboratory materials testing data. A key table 

in this module is TST_L05B, which contains layer thickness and composition 

information based on measurements from the test section site. 

11 

CHAPTER 3. ADMINISTRATION MODULE 

The Administration (ADM) module contains the master test section control table, tables that 

describe the structure and content of the database, and general comments tables. Unlike tables in 

the other modules, the first three letters of the table name do not identify tables in the ADM 

module. Tables in this module are EXPERIMENT_SECTION (the master control table for test 

sections), LTPPDD (the data dictionary that describes each field in each table), CODES 

(describes codes used in the database), COMMENTS_GENERAL (a general comments table), 

and REGIONS (contains a mapping of States and Provinces to LTPP operations administrative 

designations). 

3.1 EXPERIMENT_SECTION TABLE 

This can be considered the master table for the entire database. All test sections must have 

entries in this table. This table contains information on test section experiment assignments, 

monitoring assignments, dates when a test section changed experiments, dates when maintenance 

or rehabilitation treatments were applied, types of treatments applied, and monitoring status. 

This table has three key fields: STATE_CODE, SHRP_ID, and CONSTRUCTION_NO. 

STATE_CODE and SHRP_ID uniquely identify a test section or SPS project. 

STATE_CODE is a two-digit code used to identify the State or Province where a test section is 

located. This code is defined in the STATE_PROVINCE code type in the CODES table. These 

codes are, in part, based on the Federal Information Processing Standards (FIPS) codes and 

include codes for agencies not participating in the LTPP program. 

SHRP_ID is a four-character identifier for the test section. For GPS test sections, the number 

has no significance other than being unique when combined with the STATE_CODE. For SPS 

sections, the second character represents the experiment number; the third and fourth characters 

identify the sections at the project; and the first character is typically “0” for the first such project 

constructed in a given State or Province, “A” for the second such project, and so on. SPS 

SHRP_ID numbers ending in “00” are a project-level identifier and do not represent actual test

sections. However, when an SPS section changes experiment type because of a rehabilitation 

event, it will often be transferred into a GPS rehabilitation experiment, although the SHRP_ID 

will stay the same. The EXPERIMENT_NO field (described below) should always be used to 

determine the actual experiment classification. 

CONSTRUCTION_NO identifies changes in the pavement structure caused by rehabilitation 

treatments or application of maintenance treatments. When a section first enters the LTPP 

program, it is assigned a CONSTRUCTION_NO of 1. CONSTRUCTION_NO is incremented 

by 1 for each subsequent maintenance or rehabilitation event regardless of its impact on the 

pavement structure. For example, crack sealing causes a new construction event to be generated, 

even though it does not cause a significant change in the experiment assignment or pavement 

structure. 

13 
CN_ASSIGN_DATE identifies the date that the CONSTRUCTION_NO became active. For a 

CONSTRUCTION_NO of 1, this is the date that the section entered the LTPP program, 

otherwise it is the date of the maintenance or rehabilitation activity that triggered the change in 

CONSTRUCTION_NO. 

CN_CHANGE_REASON describes the maintenance or rehabilitation activity that triggered the 

change in CONSTRUCTION_NO. This is a code of the type MAINT_WORK. 

RECORD_STATUS is described in the Quality Control section of this document. The 

RECORD_STATUS field in EXPERIMENT_SECTION reflects the availability and 

completeness of critical data relating to that section throughout the database. 

GPS_SPS is a code to indicate whether a section is classified as a GPS or SPS experiment for 

that CONSTRUCTION_NO. 

EXPERIMENT_NO is a code indicating to which GPS or SPS experiment the pavement 

section is assigned. This two-character code consists of a number followed by an optional suffix 

letter. The suffix is used for some experiments to indicate a subcategory of test sections. 

EXPERIMENT_NO is a code of the type EXPERIMENT. 

STATUS is a code indicating the current monitoring status of a section. A null value indicates 

that the test section has been approved and has an active monitoring status. A value of “O” 

indicates that the test section has been placed “out of study” and no future monitoring 

measurements will be made. This field is set to O when a test section goes out of study. At that 

time, the STATUS field in all records in EXPERIMENT_SECTION with a matching 

STATE_CODE and SHRP_ID is set to O. 

ASSIGN_DATE is the date when a test section is assigned to the LTPP experiment. The 

experiment designation for a test section is the combination of EXPERIMENT_NO and 

GPS_SPS fields in the record. When a section is first accepted into the LTPP program, 

ASSIGN_DATE is the acceptance date. ASSIGN_DATE must precede any LTPP monitoring 

measurements taken on the test section for the associated experiment. When a test section 

changes experiments because of rehabilitation, ASSIGN_DATE is the construction start date and 

should equal the CN_ASSIGN_DATE (i.e., ASSIGN_DATE(CN+1) = 

CN_ASSIGN_DATE(CN+1), if EXPERIMENT_NO(CN) ≠ EXPERIMENT_NO(CN+1), where 

CN is the CONSTRUCTION_NO).

DEASSIGN_DATE is the date when a test section changed to another experiment or was placed 

in the out-of-study status in the LTPP program (STATUS = O). This field should be null until a 

rehabilitation construction event occurs that causes a change in EXPERIMENT_NO or the test 

section goes out of test. When a test section changes experiments because of rehabilitation, the 

DEASSIGN_DATE for the previous CONSTRUCTION_NO (CN) should equal the 

CN_ASSIGN_DATE for the next CN (i.e., DEASSIGN_DATE(CN) = 

CN_ASSIGN_DATE(CN+1), if EXPERIMENT_NO(CN) ≠ EXPERIMENT_NO(CN+1)). If a 

maintenance-related construction event occurs that does not result in an experiment change, the 

DEASSIGN_DATE for the previous CN should equal the DEASSIGN_DATE for the next CN 

14 
(i.e., DEASSIGN_DATE(CN) = DEASSIGN_DATE(CN+1) (even if NULL), if 

EXPERIMENT_NO(CN) = EXPERIMENT_NO(CN+1)). 

SEAS_ID is an agency-specific SMP identification code indicating that SMP measurements 

were made for the corresponding construction number. SEAS_ID is set to A for the first SMP 

site installed in a State, B for the second site, and so on. This field is only populated for 

construction numbers in which SMP data have been collected. When a construction event occurs 

on an SMP test section that results in termination of its participation in the SMP, or if SMP 

monitoring is terminated prior to occurrence of a new construction event, the SEAS_ID is set to 

null in the EXPERIMENT_SECTION record corresponding to the new CN for which no SMP 

data are available. 

SUPPLEMENTAL identifies supplemental test sections. A value of “S” identifies a 

supplemental test section. 

EXP_SECT_RS is a QC summary field like RECORD_STATUS, except that it reflects the 

quality and completeness of data in the EXPERIMENT_SECTION table only, rather than the 

entire database. 

BASIC_INFO_RS is a QC summary field that reflects the quality and availability of basic 

inventory information for the section. 

PAV_STRUCT_RS is a QC summary field that reflects the quality and availability of pavement 

structure information in the TST_L05B table. 

TRAFFIC_RS is a QC summary field that reflects the quality and availability of traffic data for 

the section. 

CLIMATIC_RS is a QC summary field that reflects the quality and availability of climate data 

for the section. 

3.2 LTPPDD Table 

The LTPPDD table is the online data dictionary for the LTPP pavement performance database. It 

defines each field in each table in the database. Critical fields include FIELDNAME, 

TABLENAME, and DESCRIPTION. This table is a vital reference when searching for 

appropriate fields for the extraction of data for research purposes. 

FIELDNAME is the name of the specific field that is defined by the LTPPDD entry. 

TABLENAME is the name of the table in which the field denoted by FIELDNAME resides. 

Table names generally begin with a three-letter indicator of the data module. For instance, the 

SMP_FROST_PENETRATION table is part of the SMP module. 

15 
DESCRIPTION is a short description of the field. For instance, the NORM_RESISTIVITY 

field has this entry under DESCRIPTION: “Normalized resistivity–It is the electrical resistivity 

of the soil at the measurement depth, relative to the extreme values at that depth.” 

DATA_TYPE specifies the Oracle format data type of the specified field. These fields are 

typically a VARCHAR (variable-length character field), DATE, or NUMBER (numeric field). 

DATASHEET specifies the source of the data stored within the specified field. Typically, this is 

a paper datasheet number; however, it may be a filename or individual’s name. Entries in this 

field may not be current or complete. 

ITEM is the item number of the form denoted within the DATASHEET field. This is the origin 

of the data that reside within the specified field. Entries in this field may not be current or 

complete. 

LEGALTXT is a description of the codes that are valid for this field. It can be linked to the 

CODETYPE field in the CODES table. 

QA_MINIMUM indicates whether the level-C checks are applicable to this field. An “X” in the 

QA_MINIMUM field indicates that data must be present in the specified field for it to pass the 

level-C checks. Entries in this field may not be current or complete. 

QA_RANGE indicates the acceptable range of values for this field for the data to pass the levelD range checks. Entries in this field may not be current or complete. 

SHEETDATE is the latest revision date for the DATASHEET from which this field was 

extracted. Entries in this field may not be current or complete. 

UNITS indicates the units used for the corresponding field. Both SI and U.S. customary units are 

included in the database. 

3.3 CODES 

Many of the elements in the database use a code value to represent alternate standard entries in a 

field. The CODES table contains a description of the codes used in the LTPP database. To 

decipher a code value, the LEGALTXT field in the LTPPDD table can be used to link to the 

CODE_TYPE field in the CODES table. 

CODETYPE is the code type as listed in the LEGALTXT field in the LTPPDD table. 

CODE is the code value. Although most codes are numeric, some are alphanumeric; therefore, 

this field is coded as alphanumeric, which creates an apparent illogical sequence when the field 

is sorted in ascending or descending order. 

DETAIL is the description of the code. 

16 
ADDL_CODE provides a second reference field for codes that require a combination of two 

codes to form a unique reference. The only two CODETYPES that use this field are COUNTY, 

in which ADDL_CODE corresponds to the STATE_PROVINCE code of the State or Province 

in which the county is located, and EXPERIMENT, in which the ADDL_CODE is “G” for GPS 

experiments and “S” for SPS experiments. 

The CODETYPES table is directly related to the CODES table. Its primary purpose is to provide 

a general description of the CODETYPE fields contained in the CODES table. Direct links 

between LTPPDD and CODES, as provided by the Table Navigator software, make the 

information in this table redundant. This table may be removed from the database in the future. 

3.4 COMMENTS_GENERAL 

The COMMENTS_GENERAL table contains general comments related to test section 

anomalies, general status, and other details that are not reflected in other data tables. Comments 

are entered in this table at the discretion of the LTPP regional data collection contractors. 

3.5 REGIONS 

The REGIONS table is perhaps the simplest table in the database. It consists of two fields–

STATE_CODE and REGION_CODE. This table allows a user to sort State and Provincial 

agencies by the LTPP administrative region. In the past, this table had not been distributed since 

its use is primarily for internal LTPP operations. 

17 

CHAPTER 4. AUTOMATED WEATHER STATION MODULE 

Automated Weather Stations (AWS) have been installed near almost all SPS-1, -2, and -8 project 

sites. This equipment measures site-specific climatic information. The data in the AWS module 

contains some data parameters that are also stored in the climatic tables. The significant 

exception is that AWS data include solar radiation. The AWS tables are structured to provide 

users with monthly, daily, and hourly climate statistics. LTPP regional contractors are 

responsible for equipment maintenance, data collection, review, and processing. 

Every request for AWS data should include AWS_LINK. 

4.1 IMPORTANT FIELDS 

AWS_ID is a key field in the AWS data tables used to link the data to SPS project sites and 

other nearby test sections. At locations where multiple SPS projects are co-located on the same

site, such as in Delaware, Nevada, and Ohio, since AWS_ID is not always the same as the 

combined STATE_CODE and SHRP_ID (project ID for SPS projects), AWS_LINK should 

always be used to find AWS data for a given SPS project or GPS section. 

4.2 AWS TABLES 

AWS_LINK: This table provides the link between the weather station identification used in the 

AWS tables and the associated SPS project ID or GPS SHRP_ID. 

AWS_LOCATION: This table contains information regarding the coordinates for the location 

of each weather station. Because of logistical factors regarding the availability of electricity and 

communications, AWS may be located a relatively short distance from the project site. Users 

should evaluate the potential impact of this displacement on their analytical objectives. 

AWS_HOURLY_DATA: This table contains hourly climate statistics, including air 

temperature, humidity, precipitation, solar radiation, wind speed, and wind direction. This is the 

smallest unit of time for which AWS data are available. 

AWS_DAILY_DATA: This table contains daily statistics for the AWS sites. When possible, the

information is provided by the data logger at the AWS site without the need for further 

computation. When data from the data logger are unavailable or otherwise problematic, the 

values in the daily table may be computed from the corresponding hourly data, if available. 

AWS_HUMIDITY_MONTH: This table contains monthly humidity statistics from LTPP 

AWS. These statistics are calculated from daily data for months where 24 or more days of data 

are available. 

AWS_PRECIPITATION_MONTH: This table contains monthly precipitation statistics from

LTPP AWS. These statistics are calculated from daily data for months where 24 or more days of 

data are available. 

19 
AWS_SOLAR_MONTH: This table contains monthly solar radiation statistics from LTPP 

AWS. These statistics are calculated from daily data for months where 24 or more days of data 

are available. 

AWS_TEMP_MONTH: This table contains monthly air temperature statistics from LTPP 

AWS. These statistics are calculated from daily data for months where 24 or more days of data 

are available. 

AWS_WIND_MONTH: This table contains monthly wind statistics from LTPP AWS. These 

statistics are calculated from daily data for months where 24 or more days of data are available. 

20 
CHAPTER 5. CLIMATE MODULE 

The Climate (CLM) module contains general environmental information from weather stations 

located near test sections. In addition to the measurements from these nearby weather stations, a 

test site-specific statistical estimate based on as many as five nearby weather stations is 

available. The statistical estimates are called “virtual weather stations.” Raw climatic data from

the operating weather stations (OWS) are stored in tables whose names begin with CLM_OWS. 

The virtual weather station (VWS) statistics are stored in tables whose names begin with 

CLM_VWS.

A substantial amount of background data is kept in offline climatic tables. Raw climatic data 

collected from the National Climatic Data Center (NCDC) and the Canadian Climatic Center 

(CCC) (for Canadian test sections) are included. These data consist of daily measurements for 

the LTPP selected parameters. To summarize the daily measurements, monthly and annual 

statistics (mean, standard deviation, minimum, maximum, count, and total) have been calculated. 

Selected parameters are also available as annual summaries. As of this writing, the last year for 

which information is included is 1996. 

5.1 IMPORTANT FIELDS 

VWS_ID is a key field in the CLM_VWS_* data tables used to link the data from the VWS to 

SPS and GPS sections. Because the VWS_ID is not always the same as the combined 

STATE_CODE and SHRP_ID (project ID for SPS projects), CLM_SITE_VWS_LINK (and 

SPS_GPS_LINK, if necessary) should always be used to find AWS data for a given SPS project 

or GPS section. 

5.2 CLM TABLES 

5.2.1 Online CLM Tables 

The following CLM tables are included in the database: 

CLM_SITE_VWS_LINK: This table provides the link between the VWS and the test section 

for which data are being provided. When an SPS section is co-located with a GPS section, the 

SPS section will not be in this table and the information will need to be accessed with the help of 

SPS_GPS_LINK. 

CLM_OWS_LOCATION: This table contains the exact location of the OWS used to estimate 

the climatic conditions at each test section. 

CLM_VWS_OWS_LINK: This table provides the link between the VWS and the associated 

OWS. It contains the distance between the VWS and the individual OWS, and the difference in 

elevation and the bearing from the VWS to the OWS. 

CLM_VWS_HUMIDITY_MONTH: This table contains VWS monthly humidity statistics. 

The table is populated only for months with 24 or more days of data available. 

21 
CLM_VWS_HUMIDITY_ANNUAL: This table contains VWS annual humidity statistics. The 

table is populated only for years with 300 or more days of data available. 

CLM_VWS_PRECIP_MONTH: This table contains VWS monthly precipitation statistics. The 

table is populated only for months with 24 or more days of data available. 

CLM_VWS_PRECIP_ANNUAL: This table contains VWS annual precipitation statistics. The 

table is populated only for years with 300 or more days of data available. 

CLM_VWS_TEMP_MONTH: This table contains VWS monthly temperature statistics. The 

table is populated only for months with 24 or more days of data available. 

CLM_VWS_TEMP_ANNUAL: This table contains VWS annual temperature statistics. The 

table is populated only for years with 300 or more days of data available. 

CLM_VWS_WIND_MONTH: This table contains VWS monthly wind statistics. The table is 

populated only for months with 24 or more days of data available. 

CLM_VWS_WIND_ANNUAL: This table contains VWS annual wind statistics. The table is 

populated only for years with 300 or more days of data available. 

5.2.2 Offline CLM Tables 

The following CLM tables are not included in the database. They are stored offline; however, 

they are available. Please contact LTPP customer service for any of these tables. 

CLM_VWS_DATA_DAILY: This table contains VWS daily data calculated from the daily 

OWS data. This table is stored offline. 

CLM_OWS_HUMIDITY_MONTH: This table contains OWS monthly humidity statistics. 

The table is populated only for months with 24 or more days of data available. This table is 

stored offline. 

CLM_OWS_HUMIDITY_ANNUAL: This table contains OWS annual humidity statistics. The 

table is populated only for years with 300 or more days of data available. This table is stored 

offline. 

CLM_OWS_PRECIP_MONTH: This table contains OWS monthly precipitation statistics. 

The table is populated only for months with 24 or more days of data available. This table is 

stored offline. 

CLM_OWS_PRECIP_ANNUAL: This table contains OWS annual precipitation statistics. The 

table is populated only for years with 300 or more days of data available. This table is stored 

offline. 

22 
CLM_OWS_TEMP_MONTH: This table contains OWS monthly temperature statistics. The 

table is populated only for months with 24 or more days of data available. This table is stored 

offline. 

CLM_OWS_TEMP_ANNUAL: This table contains OWS annual temperature statistics. The 

table is populated only for years with 300 or more days of data available. This table is stored 

offline. 

CLM_OWS_WIND_MONTH: This table contains OWS monthly wind statistics. The table is 

populated only for months with 24 or more days of data available. This table is stored offline. 

CLM_OWS_WIND_ANNUAL: This table contains OWS annual wind statistics. The table is 

populated only for years with 300 or more days of data available. This table is stored offline. 

CLM_OWS_DATA_DAILY: This table contains OWS daily data. This table is stored offline. 

5.2.3 Tables in Other Modules 

SPS_GPS_LINK: This table matches SPS maintenance and some rehabilitation projects to colocated GPS sections for which climatic data are provided. 

5.3 CALCULATIONS 

The values in the OWS daily, monthly, and annual tables are averages from the raw climatic data 

mentioned in the introduction. These values form the basis for the values in the VWS tables. The 

VWS_DATA_DAILY table uses values from the OWS_DATA_DAILY table, the 

VWS_*_MONTH tables get information from the OWS_*_MONTH tables, and the 

VWS_*_ANNUAL tables get information from the OWS_*_ANNUAL tables. 

5.3.1 VWS Calculations

Because the values stored in the VWS tables are computed using values from up to five different 

OWS locations, the following equation was used to weight the influence of OWS values based 

on the distance from the OWS to the VWS. 

 

∑

∑

=

= = k

i i

k

i i

mi

m

R

R

V

V

1

2

1

2

1 (1)

where: Vm = calculated data element for day m for the VWS 

 Vmi = value of data element on day m for weather station i

Ri = distance between weather station i and pavement project site 

k = number of weather stations associated with project site (up to 5) 

23 
5.3.2 Freezing Index 

To compute the monthly or annual freezing index, the following equation is used: 

∑( =

= −

n

i

FI Ti

1

0 ) (2)

where: FI = freezing index, degrees Celsius (°C) degree-days

Ti = average daily air temperature on day i, °C 

n = days in the specified period when average daily temperature is

 below freezing 

i = number of days below freezing 

When using this equation, only the days where the average daily temperature is below freezing 

are used. Therefore, the freezing index is the negative of the sum of all average daily

temperatures below 0 °C within the given period. 

24 
CHAPTER 6. DYNAMIC LOAD RESPONSE MODULE 

The Dynamic Load Response (DLR) module contains instrumentation response data collected at 

SPS test sections in North Carolina and Ohio. 

Four PCC pavement sections on the SPS-2 project in North Carolina were instrumented to 

measure pavement response under controlled loading conditions. Both deflections and strains at 

defined positions within the slab were recorded under loading by known vehicles at six locations 

(corner, midslab edge, and midslab outer wheel path) within two adjacent slabs. Pavement 

surface strains were obtained by surface-mounted strain gauges located at midslab within the 

wheel path and midslab along the slab edge. A total of 30 traces were obtained from each pass of 

the loaded vehicle with multiple repetitions at multiple speeds collected at various times of the 

day. The LTPP technical support services contractor and the North Carolina Department of 

Transportation (DOT) worked jointly during data collection operations. The LTPP technical 

support services contractor has summarized the raw data files to determine the characteristic 

peaks and valleys along the individual response traces. 

Ohio DOT and a consortium of Ohio universities took DLR measurements on instrumented 

sections in Ohio. Measurements were taken on both SPS-1 and -2 AC and PCC test sections. The 

data were collected using similar techniques to the LTPP DLR data collected in North Carolina. 

Because of the complex nature of this data module, users interested in analyses of these data 

should consult the technical references listed in appendix A. 

6.1 IMPORTANT FIELDS 

Common fields unique to the DLR tables that can be used to link related data in associated tables 

to each other include TEST_NAME, RUN_NUMBER, and TAG_ID. 

TEST_NAME represents data collection events on each test site. A data collection event can 

occur on a single day or over several consecutive test days. DLR_TEST_MATRIX provides a 

link between TEST_NAME in the DLR_MASTER_* tables and TEST_DATE. RUN_NUMBER 

in the DLR_TEST_MATRIX table can be used to differentiate between multiple test dates 

occurring during a single data collection event as indicated by TEST_NAME. This link to 

TEST_DATE is needed for DLR measurements on PCC sections; TEST_DATE is included in 

the tables containing measurements on AC test sections. The last letter in TEST_NAME 

indicates the temporal order of testing: “a” represents the first data collection event, “b” indicates 

the second, and so on. 

RUN_NUMBER represents the sequential order of runs by test trucks during the data collection 

event as defined by TEST_NAME. RUN_NUMBER is used to relate the characteristics of the 

test truck and test speed stored in the DLR_TEST_MATRIX and DLR_TRUCK_GEOMETRY 

tables to the measured pavement responses stored in the other DLR data tables. For each 

TEST_NAME event, the run number starts with 1 and is increased by 1 for each successive pass 

by the test trucks. 

25 
TAG_ID is the name assigned to the sensors installed on each test section. The combination of 

STATE_CODE, SHRP_ID, and TAG_ID uniquely identifies each response sensor. The TAG_ID

name also identifies the type of sensor, although the DLR data tables are based on the type of 

measurement. TAG_ID is a mapping on the CHANNEL the sensor is wired to on the data 

acquisition device. 

6.2 DLR TABLES 

The relational structure of the tables in the DLR module is illustrated in figure 3: 

MASTER_AC 

TEST_MATRIX TRUCK_GEOMETRY 

LVDT_TRACE_SUM_AC 

LVDT_CONFIG_AC LVDT_CONFIG_PCC 

LVDT_TRACE_SUM_PCC 

STRAIN_CONFIG_AC STRAIN_CONFIG_PCC

STRAIN_TRACE_SUM_AC STRAIN_TRACE_SUM_PCC

PRESSURE_CONFIG_AC 

PRESSURE_TRACE_SUM_AC 

Figure 3. Relational structure of data stored in the DLR module. 

MASTER_PCC 

26 
The name and contents of tables in the DLR module are as follows: 

DLR_MASTER_AC: This table contains site and instrumentation summary information for 

sections with AC surfaces. One record exists in this table for each DLR measurement cycle as 

defined by the TEST_NAME field. 

DLR_MASTER_PCC: This table contains site and instrumentation summary information for 

sections with PCC surfaces. One record exists in this table for each DLR measurement cycle as 

defined by the TEST_NAME field. 

DLR_TEST_MATRIX: This table contains information on each test sequence, including test 

date, test time, test vehicle, vehicle speed, and vehicle offset. TRUCK_ID and STATE_CODE 

are used to link to information on truck geometry stored in the DLR_TRUCK_GEOMETRY 

table. 

DLR_LVDT_CONFIG_AC: This table contains Linear Variable Differential Transformer 

(LVDT) gauge settings and location information for instrumented AC test sections. 

DLR_LVDT_TRACE_SUM_AC: This table contains response trace summaries from LVDT 

measurements on AC test sections. The response trace is reduced to a series of up to 10 points to 

capture the significant events in the response trace (most traces contain 3 to 5 points). 

DLR_LVDT_CONFIG_PCC: This table contains LVDT gauge settings and location 

information for instrumented PCC test sections. 

DLR_LVDT_TRACE_SUM_PCC: This table contains response trace summaries from LVDT 

measurements on PCC test sections. The response trace is reduced to a series of up to 10 points 

to capture the significant events in the response trace. 

DLR_PRESSURE_CONFIG_AC: This table contains pressure gauge settings and location 

information for measurements on AC test sections. 

DLR_PRESSURE_TRACE_SUM_AC: This table contains response trace summaries from

pressure measurements on AC test sections. The time-response trace is reduced to a series of up 

to 10 points to capture the significant events in the response trace (most traces contain 3 to 5 

points). 

DLR_STRAIN_CONFIG_AC: This table contains strain gauge information, configuration 

settings, and location information for measurements on AC test sections. 

DLR_STRAIN_TRACE_SUM_AC: This table contains response trace summaries from strain 

measurements on AC test sections. The time-response trace is reduced to a series of up to 10 

points to capture the significant events in the response trace (most traces contain 3 to 5 points). 

DLR_STRAIN_CONFIG_PCC: This table contains strain gauge information, configuration 

settings, and location information for measurements on PCC test sections.

27 
DLR_STRAIN_TRACE_SUM_PCC: This table contains response trace summaries from strain 

measurements on PCC test sections. The time-response trace is reduced to a series of up to 10 

points to capture the significant events in the response trace. 

DLR_TRUCK_GEOMETRY: This table contains information on the axle spacing, tire type 

and pressure, and axle width of the test trucks used for the DLR tests. 

28 
CHAPTER 7. INVENTORY MODULE 

The Inventory (INV) module contains information on pavement structures that were in service 

up to 15 years prior to selection for monitoring as an LTPP test section. This includes all of the 

test sections classified in a GPS experiment or SPS maintenance and rehabilitation experiment 

for a CONSTRUCTION_NO of 1 as defined in the EXPERIMENT_SECTION table. For SPS 

projects, the information stored in the INV module represents the pavement structure prior to 

application of the experimental treatments. INV data include location of the section, pavement 

type, layer thicknesses and types, material properties, composition, previous construction 

improvements, and other background information. 

The INV information is typically based on highway agency records for the construction project. 

The information may not represent specific conditions found at the portion of the project selected 

for monitoring. The information does not necessarily represent design values. The exception to 

this general rule is that the coordinate data are based on measurements taken by the LTPP 

program using global positioning system receivers. 

LTPP Database 

Tip!

For SPS-3 and -4 projects that include a co-located GPS test section at the 

project site, information for the SPS project in the INV tables is coded to the 

GPS test section. The SPS_GPS_LINK table contains a mapping of SPS 

projects to data stored under the linked GPS test section. 

7.1 INV TABLES 

INV_ID: This table contains section location coordinates by route number and milepost, 

longitude and latitude, direction of travel, identification if the location is part of the FHWA

Highway Performance Monitoring System, and county/parish name. Location information is 

provided in this table for sections classified in a GPS experiment or an SPS maintenance and 

rehabilitation experiment where CONSTRUCTION_NO = 1 in the EXPERIMENT_SECTION 

table. Location information for SPS projects that is based on construction of a new pavement 

structure is stored in the SPS_ID table. 

INV_AGE: This table contains construction completion and traffic open dates for the original 

pavement structure based on highway agency records. 

INV_LAYER: This table contains layer information from highway agency records. This 

information represents the pavement structure prior to LTPP monitoring. This table acts as a 

layer reference table for the other INV tables. INV tables that contain the LAYER_NO field 

reference the layer structure described in the INV_LAYER table. The layer structure in this table

may differ from the actual layer structure found at the test site. The pavement structure data in 

this table are not recommended for use in analysis of performance monitoring measurements. 

The TST_L05* tables are the best representation of the actual pavement structure for each test 

section since they are based on field drilling and sampling measurements at the site. 

29 
INV_GENERAL: This table contains general information, including pavement type, lane width, 

number of lanes, subsurface drainage features, and an estimate of the depth to a rigid layer 

beneath the test section from agency records. 

INV_GRADATION: This table contains data on the gradation of coarse, fine, and combined 

aggregates for PCC, AC, base, and subgrade. LAYER_NO in this table is used to link to the 

INV_LAYER table to indicate the type of layer. These data are based on agency project records. 

INV_MAJOR_IMP: This table contains information on the type, quantity, and cost of major 

improvements to the test section prior to acceptance for LTPP monitoring. 

INV_MODIFIER: This table contains information on asphalt modifiers used in plant-mixed 

asphalt (PMA)-bound layers. 

INV_PCC_JOINT: This table contains information on formed joints in PCC layers, including 

joint type, joint spacing, load-transfer system, joint construction methods, joint sealant, and tie 

bars. 

INV_PCC_MIXTURE: This table contains PCC mix properties, including cement type, air 

entrainment, slump, and mix proportions. 

INV_ADMIX: This table contains information on admixture type and amount for PCC layers. 

INV_AGGR_COMP: This table contains information on aggregate composition for coarse, 

fine, and combined aggregates used in AC and PCC mixtures. 

INV_AGGR_DUR: This table contains information on aggregate durability in AC and PCC

mixtures. 

INV_PCC_STEEL: This table contains information on steel reinforcement in PCC layers, 

including reinforcing steel type, diameter, design amount of longitudinal reinforcing, depth, and 

installation method. 

INV_PCC_STRENGTH: This table contains available strength data from highway agency 

records for PCC layers, including flexural strength, compressive strength, and splitting tensile 

strength. 

INV_PMA: This table contains information on PMA-bound layer aggregate properties, 

including bulk specific gravity, effective specific gravity, mineral fillers, and polish value. 

INV_PMA_ASPHALT: This table contains information on the asphalt cement used in PMAbound layers, including asphalt grade, source, specific gravity, viscosity, penetration, ductility, 

and softening point. 

30 
INV_PMA_COMPACTION: This table contains information on field compaction of PMAbound layers, including type of compaction equipment, coverage, air temperature, compacted 

thickness, and curing period. 

INV_PMA_CONSTRUCTION: This table contains information on field construction of PMAbound layers, including mixing temperature and lay-down temperatures. 

INV_PMA_ORIG_MIX: This table contains available agency information from laboratory- and 

field-compacted specimens on the mix properties of PMA-bound layers. Data included in this 

table are maximum specific gravity, bulk specific gravity, asphalt content, air voids, voids in the 

mineral aggregate, mix design stability, plant type, anti-stripping agents, and moisture 

susceptibility. 

INV_PMA_ROLLER: This table contains details on the rollers used to compact AC layers, 

including roller weight, tire pressure, and roller speed. 

INV_SHOULDER: This table contains shoulder composition, geometric, and structural 

properties, including surface material type, width, thickness, base type, and associated details for 

PCC shoulders. 

INV_STABIL: This table contains data on stabilizing agents used in base and subbase layers. 

INV_SUBGRADE: This table contains available information on the properties of the subgrade 

from highway agency records, including plasticity indices, soil classification, soil strength, 

laboratory moisture-density relationships, in situ properties, soil suction, expansion index, frost 

susceptibility, and key gradation properties. 

INV_UNBOUND: This table contains available information on the properties of base layers 

from highway agency records, including plasticity indices, classification, strength, laboratory 

moisture-density relationships, and in situ properties. 

INV_DEICE_SITE_DATA: This table contains general information on snow removal and the 

frequency of deicer use. Data stored in this table are primarily for GPS test sections in the North 

Atlantic, North Central, and Western LTPP regions. Data were collected once at the start of the 

program in support of the SHRP research on snow and ice control. 

INV_DEICE_TYPES: This table contains a listing of the type of deicers used on test sections. 

Data stored in this table are primarily for GPS test sections in the North Atlantic, North Central, 

and Western LTPP regions. Data were collected once at the start of the program in support of the 

SHRP research on snow and ice control.

31 

CHAPTER 8. MAINTENANCE AND REHABILITATION MODULES 

The Maintenance (MNT) and Rehabilitation (RHB) modules house very similar and often related 

data, and are therefore discussed in the same chapter. In the future, it is planned to collapse the 

MNT and RHB modules into a single module to avoid confusion on where these closely related 

data types are stored. 

Major improvements to a test section after inclusion in the LTPP program are documented in the 

RHB module. The tables in this module contain information on activities such as overlay 

properties and construction, shoulder replacement, and joint repair. Rehabilitation activities 

include resurfacing, reconstruction, and the addition of lanes. Rehabilitation sometimes alters the 

pavement structure. In these cases, layer data are recorded. 

The MNT module contains data reported by highway agencies on maintenance treatments 

applied to test sections. This module primarily records activities conducted on the test section 

after inclusion in the LTPP program. However, one table contains information on maintenance 

treatments applied prior to inclusion of the test section in the LTPP study. While the data in the 

MNT tables include information such as placement of seal coats, patches, joint resealing, 

milling, and grooving, users should also examine information stored in the RHB module since 

these two activities are closely related. Unlike the RHB module, there is no significant pavement 

structure change from a maintenance event, and therefore no maintenance layer table exists. 

Regardless of whether a treatment is considered maintenance or rehabilitation, the pavement 

structure will always be represented in the appropriate TST tables. Chapter 14 contains more 

information on TST tables. 

Participating highway agencies are requested to notify the LTPP regional office prior to 

performing maintenance or rehabilitation on a highway segment containing an LTPP section. 

This allows the regional office to collect any necessary monitoring data to identify the condition 

of the pavement prior to the activity. Data are collected on pavement condition before and after 

all rehabilitation and many maintenance activities. States provide information on paper forms 

describing the actual work done. 

Some types of rehabilitation do not fit either the GPS or SPS experiments. Sections receiving 

those treatments are placed out of study, are no longer studied after rehabilitation, and do not 

have data in this module for that treatment. 

8.1 IMPORTANT FIELDS 

IMP_TYPE provides information on the type of maintenance or rehabilitation performed, and is 

used in both MNT_IMP and RHB_IMP. The field uses a code named MAINT_WORK. Some

of these codes are very similar and, therefore, one type of activity may be represented by 

different codes in different records. 

 

33 
LTPP Database 

Tip!

For SPS maintenance and rehabilitation experiments, much of the data related 

to the experimental maintenance treatments are stored in tables in the SPS 

module. 

This field should be used to determine which other MNT or RHB tables contain the specifics of 

the activity. Table 3 shows the general relationships between IMP_TYPE and the MNT and 

RHB tables. Because of the variability in the maintenance and rehabilitation improvements, and 

the use of SPS_* tables for some of these data, different tables may be completed for different 

projects, and data may not be stored in the expected MNT or RHB table for a given IMP_TYPE 

code. Data may not always be available for a given improvement, and when 

DATA_AVAIL_IMS is “N”, there will be no data in other MNT and RHB tables. 

Table 3. IMP_TYPE and expected location of data in MNT and RHB tables. 

IMP_TYPE Improvement Type Expected Location of Specific Data in 

MNT and RHB Tables 

1 Crack Sealing

MNT_PCC_CRACK_SEAL

MNT_ASPHALT_CRACK_SEAL 

2 Transverse Joint Sealing MNT_PCC_JOINT_RESEAL 

3 Lane-Shoulder Longitudinal Joint Sealing MNT_PCC_JOINT_RESEAL 

4 Full-Depth Transverse Joint Repair Patch MNT_PCC_FULL_DEPTH

5 Full-Depth Patching of PCC Pavement Other Than at Joint MNT_PCC_FULL_DEPTH

6 Partial-Depth Patching of PCC Pavement Other Than at

Joint MNT_PCC_PART_DEPTH 

7 PCC Slab Replacement MNT_PCC_FULL_DEPTH 

8 PCC Shoulder Restoration RHB_RESTORE_PCC_SHOULDER

9 PCC Shoulder Replacement RHB_RESTORE_PCC_SHOULDER

10 AC Shoulder Restoration RHB_RESTORE_AC_SHOULDER 

11 AC Shoulder Replacement RHB_RESTORE_AC_SHOULDER

12 Grinding Surface MNT_GMC

13 Grooving Surface MNT_GMG 

14 Pressure Grout Subsealing RHB_SUBSEALING_PCC 

16 Asphalt Subsealing RHB_SUBSEALING_PCC

19 AC Overlay RHB_ACO_*

RHB_PMA_* 

20 PCC Overlay RHB_PCCO_*

21 Mechanical Premix Patch MNT_ASPHALT_PATCH 

22 Manual Premix Spot Patch MNT_ASPHALT_PATCH 

23 Machine Premix Patch MNT_ASPHALT_PATCH 

24 Full-Depth Patch of AC Pavement MNT_ASPHALT_PATCH 

25 Patch Pot Holes: Hand Spread, Compacted With Truck MNT_ASPHALT_PATCH 

26 Skin Patching MNT_ASPHALT_PATCH

27 Strip Patching MNT_ASPHALT_PATCH 

28 Surface Treatment, Single Layer MNT_ASPHALT_SEAL 

29 Surface Treatment, Double Layer MNT_ASPHALT_SEAL 

30 Surface Treatment, Three or More Layers MNT_ASPHALT_SEAL 

34 
Table 3. IMP_TYPE and expected location of data in MNT and RHB tables (continued). 

IMP_TYPE Improvement Type Expected Location of Specific Data in 

MNT and RHB Tables 

31 Aggregate Seal Coat MNT_ASPHALT_SEAL 

32 Sand Seal Coat MNT_ASPHALT_SEAL 

33 Slurry Seal Coat MNT_ASPHALT_SEAL 

34 Fog Seal Coat MNT_ASPHALT_SEAL 

35 Prime Coat MNT_ASPHALT_SEAL 

36 Tack Coat MNT_ASPHALT_SEAL 

37 Dust Layering MNT_ASPHALT_SEAL 

38 Longitudinal Subdrainage RHB_SUBDRAINAGE

39 Transverse Subdrainage RHB_SUBDRAINAGE 

40 Drainage Blankets RHB_SUBDRAINAGE

41 Well System RHB_SUBDRAINAGE

42 Drainage Blankets With Longitudinal Drains RHB_SUBDRAINAGE 

43 Hot-Mix Recycled AC RHB_HMRAP_*

RHB_PMA_* 

44 Cold-Mix Recycled AC RHB_CMRAP_*

RHB_PMA_* 

45 Heater Scarification, Surface-Recycled AC RHB_HEATER_SCARIF 

46 Crack-and-Seat PCC Pavement as Base for New AC 

Surface RHB_CRACK_SEAT_PCC 

47 Crack-and-Seat PCC Pavement as Base for New PCC 

Surface RHB_CRACK_SEAT_PCC 

48 Recycled PCC RHB_RCYPCC_*

RHB_PCCO_*

49 Pressure Relief Joints in PCC Pavements RHB_PRESSURE_RELIEF 

50 Joint Load-Transfer Restoration in PCC Pavements RHB_LOAD_TRANSFER 

51 Mill Off AC and Overlay With AC 

RHB_MILL_AND_GRIND 

RHB_ACO_*

RHB_PMA_* 

52 Mill Off AC and Overlay With PCC RHB_MILL_AND_GRIND 

RHB_PCCO_*

53 Other

54 Partial-Depth Patching of PCC Pavements at Joints MNT_PCC_PART_DEPTH

55 Mill Existing Pavement and Overlay With Hot-Mix AC 

RHB_MILL_AND_GRIND 

RHB_HMRAP_*

RHB_PMA_* 

56 Mill Existing Pavement and Overlay With Cold-Mix AC 

RHB_MILL_AND_GRIND 

RHB_CMRAP_*

RHB_PMA_* 

DATA_AVAIL_IMS in MNT_IMP and RHB_IMP indicates whether information on the 

maintenance or rehabilitation activity is available in other MNT or RHB tables. The creation of a 

record in MNT_IMP or RHB_IMP is an important step in the process of assigning a construction 

number, and this field is necessary so that entries can be made in the MNT_IMP or RHB_IMP 

tables before the specifics of the activity are known. 

35 
8.2 MNT TABLES 

MNT_IMP: This table contains a listing of the various maintenance activities conducted on each 

test section after its inclusion in the LTPP program and the date on which these treatments were 

applied. 

MNT_PCC_CRACK_SEAL: This table contains crack sealing information for PCC 

pavements, including the type of sealant used, how it was applied, and how much sealing was 

performed. 

MNT_PCC_FULL_DEPTH: This table contains information on full-depth PCC repair, 

including the reasons for the repair, the size of the replacement slab, the material used for 

replacement, the interface of the replacement with the existing pavement, and finishing/curing 

methods. 

MNT_PCC_JOINT_RESEAL: This table contains joint resealing information for PCC

pavements, including information on the removal of existing joint sealant, the application and 

type of the new sealant, and the quantity of sealing performed. 

MNT_PCC_PART_DEPTH: This table contains information on partial-depth patching for 

PCC pavements, including the reasons for patching, the type of patching performed, the material 

used for patching and material properties, jointing, and curing methods for PCC patches. 

MNT_ASPHALT_CRACK_SEAL: This table contains crack sealing information for AC 

pavements, including the type of sealant used, how it was applied, and how much sealing was 

performed. 

MNT_ASPHALT_PATCH: This table contains patching information for AC pavements, 

including the reasons for patching, the size of patching, and patching techniques. 

MNT_ASPHALT_SEAL: This table contains seal-coat application information for AC

pavements, including the reasons for sealing, the type and properties of the sealant used, and 

application information. 

MNT_GMG: This table contains information on diamond grinding, milling, and grooving of all 

pavement surface types, including the reasons for treatment and the details of the treatment type 

and application. 

MNT_COST: This table contains cost information for maintenance activities. Because of 

differences in the way highway agencies compute costs, users should expect inconsistencies in 

cost information. 

MNT_HIST: This table contains information on section maintenance that occurred prior to the 

section’s inclusion in the LTPP program, including only basic information such as type and 

quantity of maintenance. 

36 
8.3 RHB TABLES 

8.3.1 Nonrehabilitation-Specific Tables 

These tables are not specific to any one type of rehabilitation, and may be filled out regardless of

the rehabilitation performed. RHB_IMP will be filled out for every rehabilitation event, and 

RHB_LAYER will be completed only for those rehabilitations that alter the layer structure. 

RHB_IMP: This table contains a complete list of the rehabilitation treatments placed after the 

test section was included in the LTPP program. This table also contains when the treatments 

were placed.

RHB_LAYER: This table contains changes to the layer structure based on information provided 

by the State or Provincial highway agency. This information should not be used when 

conducting analyses on long-term pavement performance; however, it is considered useful when 

conducting a detailed analysis of an individual section(s). 

RHB_CAUSE_INFO: This table contains information on the cause(s) of rehabilitation for a test 

section and the scheduled start date for the rehabilitation. 

8.3.2 RHB Tables for AC Overlays 

8.3.2.1 RHB_PMA_* Tables 

These tables contain information on the construction of AC overlays. They will be used

regardless of whether the overlay is recycled AC or not. They will probably be populated when 

IMP_TYPE = 19, 43, 44, 51, 55, or 56. 

RHB_PMA_COMPACTION: This table contains compaction data for all types of AC

overlays, including information on roller types and coverage. 

RHB_PMA_CONSTRUCTION: This table contains construction data for all types of AC

overlays. This table includes plant information and lay-down temperatures. 

RHB_PMA_ROLLER: This table contains roller data for rollers used on all types of AC 

overlays, including the type, weight, and speed of the rollers used for compaction. 

8.3.2.2 RHB_ACO_* Tables 

These tables are used for nonrecycled asphalt pavement overlays. They will probably be 

populated only if IMP_TYPE = 19 or 51. 

RHB_ACO_AGGR_PROP: This table contains the properties of the aggregate used in AC 

overlays, including aggregate composition, durability, specific gravity, and gradation. 

37 
RHB_ACO_LAB_AGED_AC: This table contains the properties of the laboratory-aged asphalt 

cement used in AC overlays, including viscosity, ductility, penetration, and other asphalt cement 

properties. 

RHB_ACO_LAB_MIX: This table contains the properties of the AC laboratory mix design 

used in AC overlays, including asphalt content, air voids, specific gravity, stability, and other AC 

properties. 

RHB_ACO_MIX_PROP: This table contains the as-placed properties of the AC mix used in 

AC overlays, including asphalt content, air voids, specific gravity, stability, and other AC 

properties. 

RHB_ACO_PROP: This table contains the properties of the asphalt cement used in AC 

overlays, including the modifiers used, specific gravity, viscosity, ductility, and other asphalt 

cement properties. 

8.3.2.3 RHB_CMRAP_* Tables 

These RHB tables are used for cold-mix recycled AC overlays. They will probably be populated 

only if IMP_TYPE = 44 or 56. Since this is not a standard treatment option for the LTPP 

experiments, most of the following tables are empty. Currently, the only table populated in this 

series is RHB_CMRAP_LAB_MIX, which contains two records. 

RHB_CMRAP_COMBINED_AGG: This table contains the properties of the combined 

aggregate used in cold-mix recycled AC overlays, including aggregate composition, specific 

gravity, and gradation. 

RHB_CMRAP_COMBINE_AC: This table contains the properties of the asphalt cement used 

in cold-mix recycled AC overlays, including the modifiers used, specific gravity, viscosity, 

ductility, and other asphalt cement properties. 

RHB_CMRAP_GEN_INFO: This table contains the properties of the reclaimed aggregate and 

general information for cold-mix recycled AC overlays, including the gradation and specific 

gravity of the reclaimed aggregate, and the methods used to process and break up the existing 

pavement. 

RHB_CMRAP_LAB_AGED_AC: This table contains the properties of the laboratory-aged 

asphalt cement used in cold-mix recycled AC overlays, including viscosity, ductility, 

penetration, and other asphalt cement properties. 

RHB_CMRAP_LAB_MIX: This table contains the properties of the AC laboratory mix design 

used in cold-mix recycled AC overlays, including asphalt content, air voids, specific gravity, 

stability, and other AC properties. 

38 
RHB_CMRAP_MIX_PROP: This table contains the as-placed properties of the AC mix used 

in cold-mix recycled AC overlays, including asphalt content, air voids, specific gravity, stability, 

and other AC properties. 

RHB_CMRAP_NEW_AC_PROP: This table contains the properties of the new asphalt cement 

used in cold-mix recycled AC overlays, including viscosity, ductility, penetration, and other 

asphalt cement properties. 

RHB_CMRAP_RECLAIM_AC: This table contains the properties of the reclaimed asphalt 

cement used in cold-mix recycled AC overlays, including viscosity, ductility, penetration, and 

other asphalt cement properties. 

RHB_CMRAP_UNTREAT_AGGR: This table contains the properties of the untreated 

aggregate used in cold-mix recycled AC overlays, including aggregate composition, durability, 

specific gravity, and gradation. 

8.3.2.4 RHB_HMRAP_* Tables 

These RHB tables are used for hot-mix recycled AC overlays. They will probably be populated 

only if IMP_TYPE = 43 or 55. 

RHB_HMRAP_COMBINED_AGG: This table contains the properties of the combined 

aggregate used in hot-mix recycled AC overlays, including aggregate composition, specific 

gravity, and gradation. 

RHB_HMRAP_COMBINE_AC: This table contains the properties of the asphalt cement used 

in hot-mix recycled AC overlays, including the modifiers used, specific gravity, viscosity, 

ductility, and other asphalt cement properties. 

RHB_HMRAP_GEN_INFO: This table contains the properties of the reclaimed aggregate and 

general information on hot-mix recycled AC overlays, including the gradation and specific 

gravity of the reclaimed aggregate and the methods used to process and break up the existing 

pavement. 

RHB_HMRAP_LAB_AGED_AC: This table contains the properties of the laboratory-aged 

asphalt cement used in hot-mix recycled AC overlays, including viscosity, ductility, penetration, 

and other asphalt cement properties. 

RHB_HMRAP_LAB_MIX: This table contains the properties of the AC laboratory mix design 

used in hot-mix recycled AC overlays, including asphalt content, air voids, specific gravity, 

stability, and other AC properties. 

RHB_HMRAP_MIX_PROP: This table contains the as-placed properties of the AC mix used 

in hot-mix recycled AC overlays, including asphalt content, air voids, specific gravity, stability, 

and other AC properties. 

39 
RHB_HMRAP_NEW_AC_PROP: This table contains the properties of the new asphalt 

cement used in hot-mix recycled AC overlays, including viscosity, ductility, penetration, and 

other asphalt cement properties. 

RHB_HMRAP_RECLAIM_AC: This table contains the properties of the reclaimed asphalt 

cement used in hot-mix recycled AC overlays, including viscosity, ductility, penetration, and 

other asphalt cement properties. 

RHB_HMRAP_UNTREAT_AGGR: This table contains the properties of the untreated 

aggregate used in hot-mix recycled AC overlays, including aggregate composition, durability, 

specific gravity, and gradation. 

8.3.3 RHB Tables for PCC Overlays 

8.3.3.1 RHB_PCCO Tables 

These tables include information on PCC overlays. These tables will probably be populated 

when IMP_TYPE = 20, 48, or 52. 

RHB_PCCO_AGGR: This table contains the properties of the aggregate used in PCC overlays, 

including aggregate composition, durability, specific gravity, and gradation. 

RHB_PCCO_CONSTRUCTION: This table contains construction data for PCC overlays, 

including information on curing, temperature, and existing surface preparation. 

RHB_PCCO_JOINT_DATA: This table contains joint data for PCC overlays, including 

information on construction and expansion joints, sealants, and load-transfer devices. 

RHB_PCCO_MIXTURE: This table contains PCC mixture data for PCC overlays, including 

information on mix design, admixtures, slump, air entrainment, and other PCC mix properties. 

RHB_PCCO_STEEL: This table contains information on reinforcing steel used in PCC 

overlays, including the type and strength of the reinforcement and some placement information. 

RHB_PCCO_STRENGTH: This table contains PCC strength data for PCC overlays, including 

flexural, compressive, and tensile strength, and elastic modulus. 

8.3.3.2 RHB_RCYPCC Tables 

These tables contain information on PCC overlays using recycled PCC pavement. These tables 

will probably be populated when IMP_TYPE = 48. Since recycled PCC overlays were not an 

LTPP study topic, the tables in this module are currently empty. 

RHB_RCYPCC_COMBINED_AGGR: This table contains the properties of the combined 

aggregate used in recycled PCC overlays, including aggregate durability, specific gravity, and 

gradation. 

40 
RHB_RCYPCC_CONSTRUCTION: This table contains construction data for recycled PCC

overlays, including information on curing, temperature, and existing surface preparation. 

RHB_RCYPCC_JOINT: This table contains joint data for recycled PCC overlays, including 

information on construction and expansion joints, sealants, and load-transfer devices. 

RHB_RCYPCC_MIXTURE: This table contains PCC mixture data for recycled PCC overlays, 

including information on mix design, admixtures, slump, air entrainment, and other PCC mix 

properties. 

RHB_RCYPCC_NEW_AGGR: This table contains the properties of the new (nonrecycled) 

aggregate used in recycled PCC overlays, including aggregate composition, durability, specific 

gravity, and gradation. 

RHB_RCYPCC_STEEL: This table contains information on reinforcing steel used in recycled 

PCC overlays, including the type and strength of the reinforcement and some placement 

information. 

RHB_RCYPCC_STRENGTH: This table contains PCC strength data for recycled PCC 

overlays, including flexural, compressive, and tensile strength, and elastic modulus. 

8.3.4 Non-Overlay RHB Tables 

These tables are for rehabilitation other than AC or PCC overlays, though the rehabilitation often 

occurs in conjunction with an overlay. They are populated for a variety of IMP_TYPE’s, as 

shown in table 3. 

RHB_CRACK_SEAT_PCC: This table contains data collected from PCC crack-and-seat 

operations, including information on the breaking and seating processes used. This table may 

also be used for rubblization. 

RHB_HEATER_SCARIF: This table contains data on heater scarification surface recycling 

treatments on AC pavements, including information on the type of heater scarification,

rejuvenating agents, and compaction. 

RHB_LOAD_TRANSFER: This table contains load-transfer restoration data for PCC

pavements, including information on the type of restoration and the specifics on the placement of 

the load-transfer devices.

RHB_MILL_AND_GRIND: This table contains milling and grinding data for all pavement 

types, including the type and depth of milling or grinding. 

RHB_PRESSURE_RELIEF: This table contains data on the installation of pressure relief 

joints in PCC pavement, including information on the joint dimensions and interval, and the 

sealants and fillers used.

41 
RHB_RESTORE_AC_SHOULDER: This table contains information on the restoration of AC 

shoulders, including the structure of the shoulder and the restoration performed. 

RHB_RESTORE_PCC_SHOULDER: This table contains information on the restoration of 

PCC shoulders, including the structure of the shoulder and the restoration performed.

RHB_SUBDRAINAGE: This table contains data on retrofitted subdrainage installation, 

including information on the drainage materials used and the specifics of their placement. 

RHB_SUBSEALING_PCC: This table contains data on subsealing PCC pavement, including 

the type, properties, and placement of the sealant.

8.4 TABLES IN OTHER MODULES 

INV_MAJOR_IMP: This table contains data on major maintenance and rehabilitation 

treatments that were applied to the test section prior to its inclusion in the LTPP program. 

42 
CHAPTER 9. PAVEMENT MONITORING MODULE 

The Pavement Monitoring (MON) module contains photographic distress, manual distress, 

transverse profile distortion (ruts), longitudinal profile, deflection, friction, and drainage data. 

9.1 PHOTOGRAPHIC AND MANUAL DISTRESS 

Data stored in the MON_DIS tables provide a measure of pavement surface condition, including 

the amount and severity of cracking, patching and potholes, existence of surface deformation, 

joint defects, and other types of surface defects. Data on the transverse profile and rut-related 

distresses are stored in other tables. 

Initially, visual interpretation of high-resolution 35-mm (1.38-inch) photographic images of the 

pavement surface was the primary means used to obtain the surface distress data. A national 

distress data collection contractor was hired to take the field measurements and interpret the 

images. The images provided a photographic record that can be reviewed and reinterpreted in the 

future. Circa 1994, the frequency of the distress surveys conducted by manual inspection of test 

sections by LTPP regional contractors in the field increased.

To create a distress time history, data users are often faced with combining distresses from

photographic and manual data collection methods. The limitations of each method of data 

collection must be recognized in interpreting combined data sets, particularly when illogical time

series trends exist. 

The guidelines for distress data collection are contained in the Distress Identification Manual for 

the LTPP project. 

9.1.1 MON_DIS Tables 

Most of the distress data tables have names beginning with MON_DIS. The one exception is the 

MON_DROP_SEP table that contains shoulder dropoff and separation information. 

MON_DIS_AC_REV: This table contains distress survey information obtained by manual 

inspection in the field for pavements with AC surfaces. 

LTPP Database 

Tip!

Transverse cracks can include cracks caused by low temperature or reflection 

cracking types of mechanisms. Since the LTPP program does not classify 

cracks by these distress mechanisms, users must make these interpretations. 

Hand-drawn distress maps, 35-mm (1.38-inch) photographs, and maps of 

distress surveys conducted prior to overlay may be useful in identifying these 

types of cracking mechanisms. 

MON_DIS_CRCP_REV: This table contains distress survey information obtained by manual 

inspection in the field for continuously reinforced PCC pavements. 

43 
MON_DIS_JPCC_REV: This table contains distress survey information obtained by manual 

inspection in the field for jointed PCC pavements. 

MON_DIS_PADIAS_AC: This table contains distress survey information for AC-surfaced 

pavements interpreted from 35-mm (1.38-inch) black-and-white photographs using an early 

version of the PADIAS software for data collected prior to April 1992. Work is underway to 

reinterpret the film with version 4.2 of the PADIAS software and store the information in the 

MON_DIS_PADIAS42_AC table. 

MON_DIS_PADIAS42_AC: This table contains distress survey information for AC-surfaced 

pavements interpreted from 35-mm (1.38-inch) black-and-white photographs using version 4.2 

of the PADIAS software. 

MON_DIS_ PADIAS_CRCP: This table contains distress survey information for continuously 

reinforced PCC pavements interpreted from 35-mm (1.38-inch) black-and-white photographs 

using an early version of the PADIAS software for data collected prior to May 1991. Work is 

underway to reinterpret the film with version 4.2 of the PADIAS software and store the 

information in the MON_DIS_PADIAS42_CRCP table. 

MON_DIS_PADIAS42_CRCP: This table contains distress survey information for 

continuously reinforced PCC pavements interpreted from 35-mm (1.38-inch) black-and-white 

photographs using version 4.2 of the PADIAS software. 

MON_DIS_ PADIAS_JPCC: This table contains distress survey information for jointed PCC

pavements interpreted from 35-mm (1.38-inch) black-and-white photographs using an early 

version of the PADIAS software for data collected prior to May 1992. Work is underway to 

reinterpret the film with version 4.2 of the PADIAS software and store the information in the 

MON_DIS_PADIAS42_JPCC table. 

MON_DIS_PADIAS42_JPCC: This table contains distress survey information for jointed PCC

pavements interpreted from 35-mm (1.38-inch) black-and-white photographs using version 4.2 

of the PADIAS software. 

MON_DIS_JPCC_FAULT: This table contains manual measurements of fault height on 

individual joints and cracks taken using a Georgia-style faultmeter. 

LTPP Database 

Tip!

The MON_DIS_JPCC_FAULT table contains information on the location of 

joints and cracks on jointed PCC pavements. This information can be useful in 

interpreting FWD load-transfer measurements and profile data. 

MON_DIS_JPCC_FAULT_SECT: This table contains test section summary statistics for fault 

measurements taken on a test section on the same monitoring day. Fault-height values that are 

null or are less than -1 are excluded from the section statistics calculations. 

44 
MON_DROP_SEP: This table contains lane-to-shoulder dropoff measurements for ACsurfaced pavements. It also contains lane-to-shoulder dropoff and lane-to-shoulder separation 

measurements for PCC pavements. 

9.2 TRANSVERSE PROFILE DISTORTION 

The bulk of the data from which users can obtain information on test section rutting is based on 

interpretation of transverse profile measurements. These data are stored in tables whose names 

begin with MON_T_PROF. Early in the program, rut-depth measurements were made using a 

1.2-m (4-ft) straightedge reference. These measurements were primarily taken on SPS-3 test 

sections, although such measurements on other test sections varied by LTPP region. These data 

are stored in the MON_RUT_DEPTH_POINT table. Transverse profile measurements have been

chosen by the LTPP program over 1.2-m (4-ft) straightedge measurements because research has 

shown that, in many instances, wheel-path depressions are wider than 1.2 m (4-ft). 

Transverse profile measurements are taken using photographic and manual techniques. The 

photographic technique results in non-uniform spacing between profile points. The manual 

technique uses uniform 0.305-m (1-foot) spacing between profile points. As illustrated in figure 

4, the transverse elevations are adjusted to a reference line through the endpoints so that the 

elevations of the endpoints are zero. 

True Profile

Normalized Profile

Reference Datum

Normalize

to datum

Elevation 

Distance from outside lane edge 

 

Figure 4. Illustration of how transverse profile measurements are normalized to lane edges. 

The LTPP regional offices are responsible for collecting manual transverse profile data for their 

region. The national data collection contractor that takes the photographic distress measurements 

also takes the photographic transverse profile measurements. Measurements are typically taken 

at 15.25-m (50-ft) intervals. 

To obtain rutting information, the transverse profile shapes must be interpreted. This 

interpretation was performed under one of the LTPP-sponsored data analysis efforts. The results 

45 
of these computations are stored in the MON_T_PROF_INDEX_POINT and 

MON_T_PROF_INDEX_SECTION tables. The values in the POINT table are those computed 

for each measurement location, while the summary statistics for all measurements on a test

section are stored in the SECTION table. 

A variety of transverse profile distortion indices, which can be used to characterize rutting, are 

stored in the MON_T_PROF_ INDEX table. Quantification of rutting is complex; it is much 

more difficult than may be apparent to a casual observer. While the LTPP program has not yet 

developed indices that capture all aspects of rut characterization, two important measures of rut 

depth are based on a 1.83-m (6-ft) straightedge and lane-width wireline reference. 

The straightedge rut-depth method is based on positioning the straightedge at various locations in 

each half of the lane until the maximum displacement from the bottom of the straightedge to the 

top of the pavement surface is found. As shown in figure 5, at each measurement location, three 

surface profile distortion indices are computed for each half of the lane. These include maximum 

depth, offset from lane edge to the point of maximum depth, and depression width. 

The lane-width wireline rut indices are based on anchoring an imaginary wireline at each lane 

edge. The wire reference connects any peak elevation point that extends above the lane edges 

with straight lines. The wireline reference method is illustrated in figure 6. The same type of 

pavement surface profile distortion indices as those for the straightedge are also computed. 

Outside Lane Edge 

Offsets

Depth

Depth

Right Lane Hal Left Lane Half f

Straightedge

D Depression Width epression Width

Figure 5. Illustration of LTPP transverse pavement distortion indices based on 1.8-m (6-

ft) straightedge reference. Distortion indices are computed for each half of the 

lane, including depth, offset to point of maximum depth, and depression width. 

46 
Offsets 

Wireline Reference

Depth

Depression Width Depression Width 

Depth

Figure 6. Illustration of LTPP transverse pavement distortion indices based on lane-width 

wireline reference. Distortion indices are computed for each half of the lane, 

including depth, offset, and depression width.

The reason these indices are referred to as transverse profile distortion indices is that the location 

of the maximum depth is not constrained to the wheel path. Rutting is defined as a longitudinal 

depression in the wheel path. The algorithm was constrained only to each half of the lane. 

 

LTPP Database 

Tip!

Transverse profile statistics, based on the photographic measurement method, 

are available for PCC-surfaced pavements. This is an interesting data source 

for those interested in ruts on PCC-surfaced pavements. Manual transverse 

profile measurements on PCC surfaces are not taken. In 2001, the LTPP 

program stopped the photographic interpretation of transverse profile 

measurements on PCC pavements. 

9.2.1 MON_T_PROF Tables 

The relational structure of the MON_T_PROF tables is shown in figure 7.

MON_T_PROF_MASTER: This table contains information on the general characteristics of

transverse profile measurement data, including date, measurement device, number of profiles 

measured, and measurement width. This is the parent table for all other tables stored in the 

MON_T_PROF_* submodule. One record is created in this table for each set of transverse 

profile measurements on a test section. The content of the DEVICE_CODE field in 

MON_T_PROF_MASTER indicates the type of measurement. A value of “P” indicates a 

photographic measurement; “D” indicates a manual dipstick measurement. 

MON_T_PROF_DEV_CONFIG: This table contains information on equipment configuration 

settings used to capture, digitize, and interpret transverse profile measurements using the 

photographic and manual dipstick measurement methods. Note that transverse profile 

measurements based on the photographic method are obtained at the same time as the 

photographs for the film-based distress interpretations. 

47 
MASTER DEV_CONFIG 

Profile 

INDEX_POINT INDEX_SECTION

MON_T_PROF_PROFILE: This table contains edge-normalized transverse profile data. Up to

30 x-y points on the transverse profile are stored in this table. Field names starting with X

represent the offset from the outside lane edge; those names starting with Y are the elevation of 

the point relative to the outside-edge starting point. 

Figure 7. Relational structure among tables in the MON_T_PROF module. 

MON_T_PROF_INDEX_POINT: This table contains transverse profile distortion indices for 

each longitudinal measurement location. 

MON_T_PROF_INDEX_SECTION: This table contains summary statistics for the transverse 

profile distortion statistics stored in the MON_T_PROF_INDEX_POINT table. 

9.2.2 MON_RUT_DEPTH_POINT Table 

The MON_RUT_DEPTH_POINT table contains rut-depth information collected manually in the

field using a 1.2-m (4-ft) straightedge. These measurements were primarily limited to SPS-3 test 

sections; however, these measurements were also made on other test sections. The coverage of 

these data varies between LTPP regions. 

9.3 LONGITUDINAL PROFILE 

The vast majority of longitudinal profile measurements are taken on LTPP test sections using 

inertial profilers. To date, three models of inertial profilers have been used. The first profiler was 

the K.J. Law Engineering model DNC690. This profiler was used from June 1989 through April 

1997. The second inertial profiler used on LTPP test sections was the K.J. Law Engineering 

model T6600. The transition to the model T6600 began in July 1996. Implementation dates for 

the new equipment varied by region. In July 2002, the transition began to implement the 

International Cybernetics Corporation model MDR4086L3 profiler. Each of these profilers used 

different types of instrumentation technology. Descriptions of these profilers can be found in the 

references listed in appendix A. From a data availability perspective, only 0.305-m (1-ft) moving 

average profile data are available for measurement with the DNC690. The raw 25-mm (1-inch) 

48 
interval profile measurements are available offline for measurements taken with T6600 and 

MDR4086L3 devices. The raw data can be requested through ltppinfo@fhwa.dot.gov. 

For a small number of test sections, primarily those located in Alaska, Hawaii, and Puerto Rico, 

where it is not practical to obtain measurements using an LTPP inertial profiler, longitudinal 

profile measurements are taken using a device manufactured by FACE®, called Dipstick®, which 

is operated manually. This device measures the surface elevation at 0.305-m (1-ft) intervals. 

9.3.1 MON_PROFILE Tables 

MON_PROFILE_MASTER: This table contains information on the measurement device, 

measurement date, other measurement conditions, and computed profile and ride parameters. 

Some of the computed parameters include the International Roughness Index (IRI), the Mays 

Index, the Root Mean Square Vertical Acceleration (RMSVA), and an approximation of the 

American Association of State Highway Officials (AASHO) Road Test slope variance 

parameter. These data are collected for each measurement pass on a section. For inertial 

profilers, data are collected for at least five repeat measurement passes on the same day. 

MON_PROFILE_DATA: For inertial profilers, this table contains the 0.305- or 0.300-m (1- or 

0.98-ft) moving average of the profile measurements, stored at 0.153- or 0.150-m (0.5- or 0.49-

ft) intervals, depending on the measurement device. For the FACE Dipstick, the raw 0.305-m (1-

ft) interval measurements are collected. This is currently the largest online table in the database. 

This table is typically subdivided by STATE_CODE to reduce it to a convenient size for 

distribution. 

9.4 DEFLECTION MEASUREMENTS 

LTPP regional contractors take deflection measurements using FWDs. FWD data, pavement 

temperature gradient data, and computed parameters based on FWD measurements are stored in 

tables whose names begin with MON_DEFL. 

Because of the large volume of deflection testing conducted by the LTPP program, data recorded 

in a single FWD output file is spread across multiple tables to reduce redundancy and improve 

data storage efficiency. The overall structural relationship between the tables used to store FWD 

data is shown in figure 8. While this can be daunting to users accustomed to flat formats, with an 

understanding of the relationships between these tables, the data can be reassembled into any 

desired format. Example SQL scripts for building a data set for backcalculation are included in 

appendix C. 

Because of the size of the deflection time-history data, they are not stored in the database. Timehistory files in their native format can be requested through ltppinfo@fhwa.dot.gov. 

9.4.1 MON_DEFL Tables 

MON_DEFL_MASTER: This table contains summary information on measurements taken 

during a measurement day. Data stored in this table include test date, number of deflection 

49 
measurement passes, FWD serial number, operator, data collection software, and the format of 

the time-history files generated. This is the parent table for all other tables stored in the

MON_DEFL submodule. 

MON_DEFL_LOC_INFO: This table contains information specific to each point at which 

testing was conducted. Its contents include the time at which testing was initiated, the 

longitudinal and transverse location of the test point, and the air and pavement surface 

temperatures measured by instruments on the FWD. The LANE_NO field indicates the type of 

deflection test (basin or load transfer), the general location of the test (lane edge, wheel path, 

lane center, corner, or joint), and the type of surface material being tested. These codes are 

shown under LANE_SPEC in the CODES table. The CONFIGURATION_NO field is used to 

MASTER 

LOC_INFO 

DROP_DATA 

DEV_CONFIG 

DEV_SENSORS TEMP_DEPTHS 

TEMP_VALUES 

BUFFER_SHAPE 

EST_SENSOR_OFFSET 

Figure 8. Structural relationship between tables used to store FWD data. 

link to the MON_DEFL_DEV_CONFIG and MON_DEFL_DEV_SENSOR tables that contain 

data on sensor spacing and calibration. 

MON_DEFL_DROP_DATA: This table contains peak deflection and applied load 

measurements for every drop conducted at each test point on a section. This is currently the 

second largest table in the database. Each record represents one test drop. The 

NON_DECREASING_DEFL field is populated with a 1 if a nondecreasing deflection pattern is 

detected for a basin test. 

MON_DEFL_DEV_CONFIG: This table and its child, MON_DEFL_DEV_SENSORS, 

contain information specific to the configuration of the FWD during testing. These 

configurations are typically stable over many tests. Its contents include the number of deflection 

sensors used, load plate radius, and load cell and temperature sensor calibration factors. This 

table is linked to MON_DEFL_LOC_INFO through the CONFIGURATION_NO field. 

50 
MON_DEFL_DEV_SENSORS: This table contains deflection sensor offset, calibration factors, 

and serial numbers. This table is linked to MON_DEFL_LOC_INFO through the 

CONFIGURATION_NO field. The CENTER_OFFSET_FLAG field is populated when the 

location of a sensor is considered suspect based on analysis of the deflection basin. 

MON_DEFL_EST_SENSOR_OFFSET: This table contains estimates of deflection sensor 

offset in those cases where analysis of the deflection basin suggests that the reported location in 

the MON_DEFL_DEV_SENSOR table is not correct and corroborating evidence of sensor 

misplacement does not exist. Values in this table are determined based on engineering analysis 

of the deflection data. 

MON_DEFL_TEMP_DEPTHS: This table contains the depths at which temperature gradient 

data are collected during FWD testing. Generally, temperature measurements are taken at a 

minimum of three depths in the pavement structure. In some cases, it has been found that the 

temperature depth holes were drilled completely through the bound surface layer and into the 

base material. Data users should evaluate the hole depths against the information stored in the 

TST_L05A and TST_L05B tables to determine their position in the pavement structure. 

MON_DEFL_TEMP_VALUES: This table contains temperatures measured at the depths 

recorded in the MON_DEFL_TEMP_DEPTHS table. 

MON_DEFL_BUFFER_SHAPE: This table contains information on the four different styles of 

buffers used on the LTPP FWDs. Buffer use is aggregated by time period. 

MON_DEFL_FWDCHECK_CMNTS: This table contains comments from the results of the 

analysis of section homogeneity, nonrepresentative test pit and section data, and structural 

capacity from the FWDCHECK program. Use of the FWDCHECK program was discontinued 

by the LTPP program. Users interested in these data are cautioned that the table storage structure 

does not permit a direct association with the deflection measurement data set that the calculations

are based on. 

9.5 BACKCALCULATION TABLES

In 1997, data were extracted from the deflection data tables for backcalculation of material 

properties of layers in the pavement structure. The data used in these computations and their 

results are stored in tables whose names begin with either MON_DEFL_FLX or 

MON_DEFL_RGD. The MON_DEFL_FLX tables contain the inputs and results of the layered 

elastic analysis conducted on both flexible and rigid pavement structures. The 

MON_DEFL_RGD tables contain the inputs and results of slab analysis based on plate theory 

that was conducted on PCC-surfaced pavement structures. LTPP analysis contractors performed 

these computations. References to publications documenting these analytical procedures can be 

found on the LTPP Web site. 

These computations were performed external to the database and have not been updated. At this 

time, available FWD and related pavement structure data greatly exceed the volume of data 

51 
available at the time of the data extraction for these data. Furthermore, over time, other problems 

have been found in the data set that could affect the results. Users of these data are cautioned to 

fully evaluate the terms of the calculation and the current status of the raw data used in the 

calculations.

MON_DEFL_FLX_BAKCAL_BASIN: This table contains an average of the applied load and 

the measurements from each deflection sensor for multiple drops, at the same point, from the 

same drop height. 

MON_DEFL_FLX_BAKCAL_LAYER: This table contains information on the layer structure 

and material properties used in the backcalculation computation. BAKCAL_LAYER_NO 

conforms to the layer referencing system used by the computer program and the other 

FLX_BAKCAL tables. Links to the LTPP layer referencing method are stored in the fields 

whose names are similar to L05B_LAYER_NO_#. 

MON_DEFL_FLX_BAKCAL_POINT: This table contains the results of the elastic layer 

analytical backcalculation computation for each test point on a test section by layer type, drop 

height, and test time. Inclusion of records in this table in the section statistics is based on the 

value stored in the ERROR_RMSE field. Values in this field that are greater than 2 are not 

included in the section statistical summaries. 

MON_DEFL_FLX_BAKCAL_SECT: This table contains test section summary statistics from

the elastic layer analysis. These statistics are based on records in the 

MON_DEFL_FLX_BAKCAL_POINT table with a value of 1 in the 

SECTION_STAT_INCLUDE_FLAG field. For database users interested in the evaluation of 

multiple deflection measurement passes on the same day on SMP test sections, only aggregate 

statistical summaries for the test day are included in this table. 

MON_DEFL_FLX_NMODEL_POINT: This table contains the results of the nonlinear 

material response models for the pavement layers. Since various types of nonlinear models can 

be applied to the different pavement layers, this table contains codes that reference the model and 

the associated coefficients. Data are stored in this table for each deflection test point on a test

section. 

MON_DEFL_FLX_NMODEL_SECT: This table contains a statistical summary of the results 

of the nonlinear analysis for the complete test section. These statistics are based on records in the 

MON_DEFL_FLX_MODEL_POINT table that have a value of 1 in the 

SECTION_STAT_INCLUDE_FLAG field. 

MON_DEFL_RGD_BAKCAL_LAYER: This table contains information on the pavement 

structure input parameters used in the backcalculation based on plate theory. Information stored 

in this table includes the thicknesses of the PCC and the base layer, the modulus ratio, the 

Poisson’s ratio, and references to the layers in the TST_L05B table that may have been 

combined in this analysis. 

52 
MON_DEFL_RGD_BAKCAL_BASIN: This table contains the load, deflection basin, and 

associated parameters used in the analysis, including the average of the applied load and the 

measurements from each deflection sensor for multiple drops, at the same point, from the same

drop height. 

MON_DEFL_RGD_BAKCAL_POINT: This table contains the results of the plate theory 

backcalculation results for each test point on the test section. The table contains the analytical 

results for four models from the combination of the assumptions of dense liquid/elastic support 

and full base friction/no base friction. Based on the evaluation of the results by the analysts, the 

fields for the model results that were not considered appropriate were populated with a 999.9 

type of convention. 

MON_DEFL_RGD_BAKCAL_SECT: This table contains test section summary statistics from

the plate theory backcalculation analysis. These statistics are based on records in the 

MON_DEFL_RGD_BAKCAL_POINT table with a value of 1 in the 

SECTION_STAT_INCLUDE_FLAG field. For database users interested in evaluation of 

multiple deflection measurement passes on the same day on SMP test sections, the 

MON_DEFL_BAKCAL_RGD-* tables contain a FWD_PASS field that is used to aggregate 

statistical summaries for each measurement pass on the test day. 

9.6 FRICTION 

The Friction submodule includes only the MON_FRICTION table. This table contains the results 

of friction tests on pavement sections where the State/Provincial highway agency was willing to 

provide the data. Because of the litigious nature of this data, submission is voluntary. The LTPP 

program has no control over the data collection method, measurement equipment, or calibration 

of the equipment used for these measurements. The database does not contain surface texture 

measurements and related information that are traditionally used to link pavement properties to 

measured friction levels. 

9.7 DRAINAGE 

Tables in this module contain information on the inspection of drainage features. These tables 

are currently under construction and are expected to be available in January 2004. Tables in this 

module will contain information on the condition of the edge drain systems installed at the SPS1, -2, and -6 projects. In the future, tables may be added for other drainage feature evaluations. 

MON_DRAIN_MASTER: This table contains information on the permanent features of the 

edge drain system and the location of the lateral openings. Since the data stored in this table are 

from inspections on SPS project sites with multiple test sections, the primary keys are related to 

a project-level identifier. These data are from video inspections of the drainage system that start 

from an exposed lateral-side drain structure. The key field LATERAL_ID, in combination with 

PROJECT_STATION and NEAREST_SECTION, provides an indication of the location of the 

drainage structure being inspected. The SPS_PROJECT_STATIONS table can be used to 

understand the location of the lateral drain being inspected relative to other sections on SPS 

projects. 

53 
MON_DRAIN_CONDITION: This table contains information regarding the condition of the 

lateral openings and the area around the lateral openings at the time of inspection.

MON_DRAIN_INSPECT: This table contains information on the results of the video edge 

drain inspection. Significant events in the inspection are recorded as a function of the distance of 

insertion of the camera within the drainage pipes. 

54 
CHAPTER 10. SEASONAL MONITORING PROGRAM MODULE 

The Seasonal Monitoring Program (SMP) study is designed to measure the impact of daily and 

yearly temperature and moisture changes on pavement structures and the response to loads. 

Sixty-three sites were selected from the GPS and SPS studies and were monitored for 

temperature and moisture, and at higher than normal intervals for distress, deflection, and 

longitudinal profile. Measurements specific to sections in the SMP were made using the 

following devices: 

 

• Time-Domain Reflectometry: Subsurface moisture changes. 

• Thermistor Probes: Subsurface temperature changes. 

• Electrical Resistivity: Frost/thaw depth. 

• Piezometer: Groundwater table determination. 

• Air Temperature Probes: Ambient temperature. 

• Tipping-Bucket Rain Gauge: Precipitation. 

The data collected from these devices are stored in the tables contained in the SMP module. All 

other data collected at sites within the SMP, but not specific to sites in the SMP, are stored in the 

usual tables external to the SMP module. For example, deflection measurements on SMP test 

sections are stored in the MON_DEFL series of tables. 

At the inception of the SMP program, subsurface time-domain reflectometry and electrical 

resistivity measurements were taken on a nominal monthly cycle. In the latter part of the SMP 

program, selected sites were instrumented to take these measurements daily and, in some cases, 

subdaily to capture changes caused by rainfall. The only way to identify the sites with these 

types of daily measurements is to inspect the contents of the tables containing these data. 

In addition to the raw data as collected, several computed parameters are included that reduce 

the raw data into values in engineering units. All of the raw data used to calculate the computed 

parameters are included in the database. 

10.1 DATA TABLES 

10.1.1 Ambient Temperature and Precipitation

The ambient temperature and precipitation data collected from the onsite weather stations are 

stored in the SMP_ATEMP_RAIN series of tables. 

SMP_ATEMP_RAIN_HOUR: This table contains the average hourly temperature and the total 

hourly precipitation. Temperature or precipitation data in this table may be null if an 

instrumentation error was discovered. The hour at the end of the averaging period is stored in the 

ATEMP_RAIN_TIME field in 24-hour military-style text format. The date of the measurement 

is stored in the SMP_DATE field in a native date format. 

SMP_ATEMP_RAIN_DAY: This table contains the average, minimum, and maximum

ambient air temperatures over the course of a day; the times at which the minimum and 

maximum temperatures occurred; and the cumulative precipitation. These values are computed 

55 
directly from the SMP_ATEMP_RAIN_HOUR table when at least 18 hours of data exist for a 

day. 

10.1.2 Subsurface Temperature 

Subsurface temperatures are stored in the SMP_MRCTEMP_* series of tables (MRC is the 

manufacturer of the type of thermistor used by the LTPP program). 

SMP_MRCTEMP_AUTO_HOUR: This table contains the vast majority of subsurface 

temperature data. It includes average hourly temperatures at a series of depths; however, it must 

be linked to SMP_MRCTEMP_DEPTHS using the THERM_NO field (and the STATE_CODE 

and SHRP_ID for the section) to determine the depth at which the temperature was recorded. 

SMP_MRCTEMP_MAN: This table contains the remainder of the subsurface temperature data. 

Its format is very similar to SMP_MRCTEMP_AUTO_HOUR; however, it contains manual 

temperature measurements taken when the automatic temperature monitoring equipment was out 

of service. Like SMP_MRCTEMP_AUTO_HOUR, it must be linked to

SMP_MRCTEMP_DEPTHS to determine the depth at which the temperature was measured. 

SMP_MRCTEMP_AUTO_DAY_STATS: This table contains the average, minimum, and 

maximum subsurface temperatures over the course of a day and the times at which the minimum 

and maximum temperatures occurred. These values are based on either the minute-by-minute 

readings recorded by the data logger or are computed from the averages stored in the 

SMP_MRCTEMP_AUTO_HOUR table when recomputation of the daily statistics is needed for 

adjustments, and like that table, it must be linked to SMP_MRCTEMP_DEPTHS to determine 

the depth at which the temperature was measured. 

SMP_MRCTEMP_DEPTH: This table contains the depths at which each temperature probe at 

an SMP section was installed and the date of installation. The primary use of this table is to link 

to other SMP_MRCTEMP_* tables, using the STATE_CODE, SHRP_ID, and THERM_NO 

fields, to determine the depth corresponding to a temperature reading. In some rare cases, 

STATE_CODE, SHRP_ID, and THERM_NO do not resolve to a unique depth because the 

thermistors were reinstalled at slightly different depths at some point after the initial installation. 

In these cases, the link must be further refined using the INSTALL_DATE field. 

10.1.3 Subsurface Moisture Content 

The LTPP SMP uses time-domain reflectometry (TDR) to measure subsurface moisture content. 

A description of the process is located in chapter 2 of the Seasonal Monitoring Program 

Guidelines. 

SMP_TDR_AUTO_MOISTURE: This table contains the volumetric and gravimetric moisture 

contents calculated using TDR (the dry densities used to convert volumetric to gravimetric 

moisture content are located in SMP_MOISTURE_SUPPORT). The depths at which these 

moisture contents were calculated can be determined by linking to 

SMP_TDR_DEPTHS_LENGTHS using STATE_CODE, SHRP_ID, and TDR_NO. Further

56 
information on the calculation of these computed parameters can be found in An Input for 

Moisture Calculations–Dielectric Constant From Apparent Length, Publication No. FHWA-RD99-201. 

SMP_TDR_AUTO: This table contains a flat representation of the TDR waveform. The 

measured reflected waveform is sampled at 245 intervals and stored in the WAVP_1 through 

WAVP_245 fields. The distance interval between samples is recorded in the 

DIST_WAV_POINTS field. This table is only useful to the analyst who is interested in 

reinterpreting the raw TDR data. 

SMP_TDR_MANUAL_DIELECTRIC: This table contains dielectric constants interpreted 

from TDR measurements recorded on paper strip charts during installation of SMP 

instrumentation. The protocol for interpretation of the manual TDR measurements is stored in 

LTPP Directive SM-28. 

SMP_TDR_AUTO_DIELECTRIC: This table contains the dielectric constant interpreted from

the waveforms stored in SMP_TDR_AUTO and several intermediate calculations. 

SMP_TDR_DEPTHS_LENGTHS: This table contains information on the physical 

characteristics of the TDR probes, including the depth at which the probe is installed, the length 

of the probe, and its installation date. The primary use of this table is to link to other 

SMP_TDR_* tables, using the STATE_CODE, SHRP_ID, and TDR_NO fields, to determine the 

depth corresponding to a moisture reading. In some rare cases, STATE_CODE, SHRP_ID, and 

TDR_NO do not resolve to a unique depth because the thermistors were reinstalled at slightly 

different depths at some point after the initial installation. In these cases, the link must be further 

refined, using the INSTALL_DATE field. A secondary use of this table is to determine the 

length of the TDR probe, which is necessary when reinterpreting the TDR data. 

SMP_TDR_MOISTURE_SUPPORT: This table contains the dry density of soils sampled 

from areas adjacent to each of the TDR probes. These data are primarily useful for converting 

volumetric moisture contents to gravimetric moisture contents. For some samples, gradation and 

plastic limit data are also available. 

SMP_DRY_DENSITY: This table is an alternate source of soil dry density data. Data are 

limited to one dry density per SMP site, with the test conducted on samples obtained from

approximately 1 m below the pavement surface. In practice, the utility of this table is limited 

because of low data availability. 

SMP_GRAV_MOIST: This table contains the results of laboratory gravimetric moisture testing 

of materials sampled adjacent to each TDR probe at the time of installation. 

57 
10.1.4 Frost Penetration 

The LTPP SMP uses a combination of subsurface temperature and electrical resistivity to 

estimate frost penetration. The soil resistivity probes used by the LTPP program are all identical; 

however, the data have been collected in slightly different ways, as described below. 

SMP_ERESIST_MANUAL_CONTACT: This table contains manually collected voltage and 

current, and the calculated resistance between adjacent electrodes on the probe. This resistance is 

the contact resistance. The depths of the electrodes can be determined by linking 

ELECTRODE_START and ELECTRODE_END to ELECTRODE_NO in the 

SMP_ERESIST_AUTO_ABF table. 

SMP_ERESIST_MAN_4POINT: This table contains the manually collected voltage and 

current, and the calculated bulk resistivity of the material around the probe using the four-point 

method. This process is described further in chapter 2 of Seasonal Monitoring Program 

Guidelines. The depths of the electrodes across which these measurements were made can be 

determined by linking EAMP_START and EAMP_END to ELECTRODE_NO in the 

SMP_ERESIST_AUTO_ABF table. 

SMP_ERESIST_AUTO: This table contains automatically collected voltage data between 

adjacent electrodes on the probe. Since the current associated with this voltage varies over time, 

the absolute contact resistance cannot be calculated. However, significant changes in voltage 

with depth at a given time can be used to indicate changes in the freeze state of the soil. The 

depths of the electrodes across which these measurements were made can be determined by 

linking ELECTRODE_START and ELECTRODE_END to ELECTRODE_NO in the 

SMP_ERESIST_AUTO_ABF table. 

SMP_ERESIST_AUTO_ABF: This table contains data from the ABF data logger that is 

automatically calibrated using an internal resister (these calibrations are stored in 

SMP_ERESIST_ABF_RES_VA). Therefore, unlike SMP_ERESIST_AUTO, both the voltage 

and the contact resistance are available from this table. 

SMP_ERESIST_ABF_RES_VA: This table contains automatic calibration data from the ABF 

data logger. Both the total voltage applied by the data logger and the voltage drop across the 

internal calibration resister are available. Generally, this table is only of use to the analyst who 

wishes to recalculate the contact resistance data stored in SMP_ERESIST_AUTO_ABF. 

SMP_ERESIST_DEPTHS: This table contains the depths at which each resistivity probe at an 

SMP section was installed and the date of installation. The primary use of this table is to link to 

other SMP_ERESIST_* tables, using the STATE_CODE, SHRP_ID, and ELECTRODE_NO 

fields, to determine the depth corresponding to a resistance or resistivity reading. In some rare 

cases, STATE_CODE, SHRP_ID, and THERM_NO do not resolve to a unique depth because 

the probes were reinstalled at slightly different depths at some time after the initial installation. 

In these cases, the link must be further refined using the INSTALL_DATE field. 

58 
SMP_FREEZE_STATE: This table contains the computed parameters necessary to determine 

whether the pavement layers at a given depth are frozen or not. It includes resistivity and contact 

resistance extracted from SMP_ERESIST_MAN_4POINT and 

SMP_ERESIST_MAN_CONTACT, the daily average temperature extracted from

SMP_MRC_TEMP_AUTO_DAY_STATS, and a determination of the freeze state of the soil 

based on these values. Information on the calculation of these computed parameters can be found 

in Freeze-Thaw Monograph for LTPP, Publication No. FHWA-RD-98-177. 

SMP_FROST_PENETRATION: This table contains an estimation of the upper and lower 

boundaries of the frozen layer based on the computed parameters in the SMP_FREEZE_STATE 

table. 

10.1.5 Depth to Water Table 

The LTPP SMP uses an observation well (this well is sometimes called an “observation 

piezometer” for reasons relating to the permitting process for drilling wells) to determine if the 

depth of the water table is within approximately 5 m from the pavement surface. In many cases, 

the observation well did not extend to the water table. 

SMP_WATERTAB_DEPTH_MAN: This table contains manual observations of the distance 

from the pavement surface to the water table. 

SMP_WATERTAB_DEPTH_AUTO: This table was originally developed to contain 

automated readings of the water table depth; however, such readings were never obtained. 

Therefore, this table contains no data. 

10.1.6 Surface Elevation Data 

Surface elevation measurements using a rod-and-level surveying method are taken at each SMP 

site at the time of FWD testing. Measurements are taken at the location of each FWD test and are 

referenced to a frost- and swell-free benchmark

SMP_ELEV_AC_DATA: This table contains surface elevation measurements for asphaltsurfaced SMP sections. At each longitudinal location, elevation measurements are typically 

taken at the pavement edge (PE), outer wheel path (OWP), midlane (ML), inner wheel path 

(IWP), and inner lane edge (ILE). To determine the actual transverse locations of these 

measurement points, this table must be linked to SMP_ELEV_AC_OFFSET using 

STATE_CODE, SHRP_ID, and SMP_DATE. 

SMP_ELEV_AC_OFFSET: This table contains the transverse offset of the elevation 

measurement locations stored in SMP_ELEV_AC_DATA. In addition, it also contains a text 

description of the equipment used to conduct the elevation survey. 

SMP_ELEV_PCC_DATA: This table contains surface elevation measurements for PCCsurfaced SMP sections. At each longitudinal location, elevation measurements are typically 

taken at the pavement edge (PE), midlane (ML), and inner lane edge (ILE). To determine the 

59 
actual transverse locations of these measurement points, this table must be linked to 

SMP_ELEV_PCC_OFFSET using STATE_CODE, SHRP_ID, and SMP_DATE. 

SMP_ELEV_PCC_OFFSET: This table contains the transverse offset of the elevation 

measurement locations stored in SMP_ELEV_PCC_DATA. In addition, it also contains a text 

description of the equipment used to conduct the elevation survey. 

10.1.7 Joint Opening and Faulting 

Joint opening and faulting measurements are typically collected concurrently with FWD testing 

at the same locations as where the load-transfer tests are conducted. The joint opening is 

measured using snap rings installed in the joint, while faulting is measured using a Georgia-style 

faultmeter (as done with standard LTPP distress surveys). 

SMP_JOINT_FAULT_DATA: This table contains joint faulting measurements for PCCsurfaced SMP sections. At each longitudinal location for which FWD load-transfer testing is 

conducted, joint faulting is measured at the pavement edge (PE), midlane (ML), and inner lane 

edge (ILE). To determine the actual transverse locations of these measurement points, this table 

must be linked to SMP_JOINT_FAULT_OFFSET using STATE_CODE, SHRP_ID, and 

SMP_DATE. 

SMP_JOINT_FAULT_OFFSET: This table contains the transverse offset of the joint fault 

measurement locations stored in SMP_JOINT_FAULT_DATA. 

SMP_JOINT_GAUGE_DATA: This table contains joint opening measurements for PCCsurfaced SMP sections. At each longitudinal location for which FWD load-transfer testing is 

conducted, the joint opening is measured at the pavement edge (PE), midlane (ML), and inner 

lane edge (ILE). To determine the actual transverse locations of these measurement points, this 

table must be linked to SMP_JOINT_GAUGE_OFFSET using STATE_CODE, SHRP_ID, and 

SMP_DATE. 

SMP_JOINT_GAUGE_OFFSET: This table contains the transverse offset of the joint opening 

measurement locations stored in SMP_JOINT_GAUGE_DATA. 

10.1.8 Additional SMP Tables 

SMP_LAYOUT_INFO: When using SMP data, it is critical to know the locations at which the 

measurements were taken. SMP_LAYOUT_INFO is the source for much of this information, 

including the location of the instrument hole where the TDR, thermistor, and resistance probes 

were installed, and the locations of the piezometer and the weather observation instrumentation. 

Longitudinal and transverse locations for joint opening and faulting, and surface elevation 

measurements are located in other tables within the SMP module, as described elsewhere in this 

chapter. 

SMP_COMMENTS: This table contains a wealth of information regarding irregularities in data 

collection. Equipment failure, unusual weather conditions such as flooding of an adjacent river, 

60 
and anything else out of the ordinary will be recorded in this table. These data are keyed to the 

section ID, date of occurrence, and the table in which the effected data is stored. 

61 

CHAPTER 11. SPECIFIC PAVEMENT STUDIES MODULE 

The Specific Pavement Studies (SPS) module contains construction and location information for 

SPS projects. The various SPS experiments are defined within table 2. New construction SPS 

projects include SPS-1, -2, -8, and -9 experiments, while SPS-3, -4, -6, and -7 designations 

identify the maintenance and rehabilitation projects. Tables with the SPS prefix contain data that 

are general to all SPS experiments. Data that are specific to an SPS experiment type are 

maintained in tables with prefixes that indicate the SPS experiment. 

Materials testing and construction details within the SPS tables vary by experiment. Tables for 

layer materials and thicknesses are included in the SPS modules for all experiments. These tables 

are similar in purpose to the INV tables for GPS sections. However, since SPS sections enter the 

program at the time of their construction or rehabilitation, the data within the SPS module reflect 

initial conditions as observed at that time. Information within this module comes from

construction data sheets that are filled out by highway agencies and LTPP regional contractors 

and from materials testing conducted by the State highway agencies on samples collected during 

and immediately following construction or rehabilitation. Data entry is done at the LTPP 

regional offices. 

 

11.1 IMPORTANT FIELDS 

Common fields unique to the SPS tables that can be used to link related data in associated tables 

to each other include STATION, LIFT_NO, ROLLER_CODE, and PROJECT_STATION_NO. 

STATION is used to denote the longitudinal position within each SPS-4 test section where 

transient dynamic response and Benkelman beam testing were conducted. STATION is the 

distance in feet from the start of the test section. The usefulness of the field for relating data from

different tables is limited since no transient dynamic response testing was ever done and hence 

the SPS4_TRANSIENT_MEASURE table is empty of data. 

LTPP Database 

Tip!

Several fields within SPS tables can be used to relate SPS table data to 

monitoring data collected at specific locations on the test sections; however, 

the user must be careful to match converted units when necessary. 

STATION_NO is used within SPS#_LAYER_THICKNESS tables to denote 

the longitudinal position relative to the start of the test section. STATION is 

used for the same purpose within the SPS4_BENKELMAN_MEASURE table 

and POINT_DISTANCE is used within the 

SPS#_TRANSFER_EFFICIENCY and SPS9_LOAD_TRANS_EFFICIENCY 

tables. The POINT_LOC field within the monitoring data tables uses meters, 

while each of the SPS fields uses feet. Attention to units is required when 

relating data through these fields. 

LIFT_NO can be useful in linking compaction information in the SPS#_PMA_COMPACTION

tables and the lift thicknesses found in SPS#_PMA_PLACEMENT_DATA. These thicknesses 

are found in fields with names such as AC_SURFACE_1ST_THICK, so the data cannot be 

directly linked to LIFT_NO values that represent the sequential numbering of PMA lifts. To do 

63 
this, a manual count of the sequential lifts recorded within the 

SPS#_PMA_PLACEMENT_DATA table is needed to find the number that matches the first lift 

of the AC surface layer, then that number must be substituted for LIFT_NO to extract the 

compaction data from SPS#_PMA_COMPACTION. 

ROLLER_CODE is also part of the SPS#_PMA_COMPACTION tables. 

SPS#_PMA_COMPACTION contains information on the compaction of each AC lift in the 

construction of the section. The variables BREAKDOWN_ROLLER_CODE, 

INTERMED_ROLLER_CODE, and FINAL_ROLLER_CODE within this table can be related 

to the ROLLER_CODE variable within the SPS#_PMA_ROLLER table, which defines the 

characteristics of each of the rollers used during construction.

PROJECT_STATION_NO is found only in SPS_INTERSECTION and denotes the position of 

any intersections or ramps in relation to the start of the first section of an SPS project. The units 

are in feet. PROJECT_STATION_NO can be compared to the SECTION_START and 

SECTION_END fields from the SPS_PROJECT_STATIONS table to determine where the 

intersection is located with respect to each of the individual test sections within the project. 

11.2 GENERAL SPS TABLES 

Within the SPS module, a series of tables exists whose names begin with SPS, with no reference 

to the number of the experiment. The data stored in these tables are common to more than one 

SPS experiment. However, these data are not always common to all SPS experiments. 

SPS_ID: This table contains information on the location of SPS project sites in the 1, 2, 8, and 9 

experiments that started with either new pavement construction or reconstruction. Location 

information for SPS projects constructed on existing pavements is stored in the INV_ID table. 

This table contains data on roadway information, elevation, latitude, longitude, and other features 

of the test section location. 

SPS_GENERAL: This table contains information on road geometry, and shoulder and drainage 

features for new construction SPS test sections classified in the 1, 2, 8, and 9 experiments. 

SPS_PROJECT_STATIONS: This table links test sections that are co-located on a project and 

provides the order in which the test sections occur in the direction of traffic flow. The stations 

stored in this table are in meters. 

SPS_INTERSECTIONS: This table contains project-level intersection information and data on 

the location of ramps, signals, and stop signs within the project boundaries. 

SPS_CUT_FILL_LOCATIONS: This table contains the order and location of the cuts and fills 

within each SPS section. Starting and ending points are recorded. 

SPS_GPS_LINK: This table links the SPS maintenance projects and some SPS rehabilitation 

projects to co-located GPS test sections. SPS projects that are not included within this table do 

not have co-located GPS test sections. 

64 
LTPP Database 

Tip! 

The SPS_GPS_LINK table can be used to link SPS projects to co-located GPS 

test sections. This table links the SHRP_ID field that identifies the projectlevel SPS site to the LINKED_GPS_ID field that matches the SHRP_ID field 

in the INV_ID table. SHRP_ID in the INV_ID table identifies the co-located 

GPS test section. Inventory, climatic, and traffic data can be shared. 

11.3 NUMBERED TABLES COMMON TO MULTIPLE EXPERIMENTS 

The fourth character of the prefix of many table names in the SPS module is a number that is 

intended to reference a specific experiment. The following tables are common to multiple 

experiments and contain the same basic information; however, they have names that differ by 

only the fourth character. In the following list, # is used as a “wild card” character to represent 

all numerical values. 

SPS#_LAYER: This table contains the pavement materials layer structure used to reference data 

stored in other tables whose names begin with a matching SPS#. This information is based on 

observations made during the construction. The layer thicknesses provided in these tables were 

often obtained from plans and specifications. These values should not be used in performance 

analyses. SPS-3 and -4 maintenance experiment sections have no LAYER tables. Information on 

the pavement structure layers for these sections can be found in the INV_LAYER table entries 

for the co-located GPS sections. 

SPS#_LAYER_THICKNESS: These tables have thickness values for each layer computed 

from elevation measurements from each test section at various offsets from the pavement edge. 

SPS-3 and -4 maintenance experiment sections have no LAYER_THICKNESS tables. 

SPS#_NOTES_AND_COMMENTS: This table contains miscellaneous comments and notes 

concerning construction operations that may have had an influence on the ultimate performance 

of the test section or that may have caused undesirable performance differences among test 

sections. SPS-3 and -4 maintenance experiment sections have no NOTES_AND_COMMENTS 

tables. 

SPS#_PMA_AC_PROPERTIES: This table contains the properties of the asphalt cement that 

was used in the PMA-bound layers of the SPS section. These properties were typically obtained 

from the asphalt supplier or from tests conducted by the State highway agency. SPS-1, -2, -8, and 

-9 experiments have PMA#_AC_PROPERTIES tables. 

SPS#_PMA_AGGREGATE_PROP: This table contains the properties of the aggregate that 

was used in the PMA-bound layers of the SPS section. These properties were typically obtained 

from the asphalt supplier or from tests conducted by the State highway agency. SPS-1, -2, -8, and 

-9 experiments have PMA_AC_PROPERTIES tables. 

SPS#_PMA_COMPACTION: This table contains compaction data, including air temperatures, 

roller information, and roller coverage for each lift of each PMA-bound layer of the SPS section. 

SPS-1, -2, -5, -6, -8, and -9 experiments have PMA_COMPACTION tables. 

65 
SPS#_PMA_CONSTRUCTION: This table contains construction data for PMA-bound layers 

of the SPS section, including paving start and end dates, and mixing/lay-down temperatures. 

SPS-1, -2, -5, -6, -8, and -9 experiments have PMA_CONSTRUCTION tables. 

SPS#_PMA_MIXTURE_PROP: This table contains mixture properties for each PMA-bound 

layer. SPS-1, -2, and -8 experiments have PMA_MIXTURE_PROP tables. 

SPS#_PMA_PLACEMENT DATA: This table contains placement data for each PMA-bound 

layer, including asphalt-treated base (ATB), permeable asphalt-treated base (PATB), binder, 

surface, and friction courses. SPS-1, -2, and -8 experiments have PMA_PLACEMENT tables. 

SPS#_PMA_ROLLER: This table contains data for each roller used on any of the PMA-bound 

layers, roller weights, tire pressures, vibration frequency and amplitude, and roller speed. The 

ROLLER_CODE field can be used to link the information within this table to that stored in 

SPS#_PMA_COMPACTION. SPS-1, -2, -5, -6, -8, and -9 experiments have PMA_ROLLER 

tables. 

SPS#_SUBGRADE_PREP: This table contains subgrade preparation data, including 

information on compaction, stabilizing agents, and lift thicknesses (fill sections). SPS-1, -2, and 

-8 experiments have SUBGRADE_PREP tables. 

SPS#_UNBOUND_AGG_BASE: This table contains placement information associated with 

unbound aggregate base layers, including compaction equipment and lift thicknesses. SPS-1, -2, 

-8, and -9 experiments have UNBOUND_AGG_BASE tables. 

SPS#_QC_MEASUREMENTS: This table contains all of the construction QC procedures and 

the measurements that were taken during construction of SPS-5, -6, and -7 test sections. 

SPS#_OVERLAY: This table contains placement data for the AC overlays, including 

equipment and plant information, surface preparation, and haul times for each AC layer. This 

table applies to SPS-5 and -6 rehabilitation experiments. 

SPS#_OVERLAY_LAYERS: This table contains information specific to each lift placed during 

AC overlay applications on SPS-5 and -6 test sections. 

SPS#_LOAD_TRANSFER: This table contains information on the restoration of load-transfer 

capacity at joints in PCC pavements within SPS-6, -7, and -9 test sections prior to the application 

of an overlay. 

SPS#_PCC_CRACK_SEAL: This table contains data on crack sealing operations that occurred 

prior to the application of an overlay on SPS-6, -7, and -9 test sections. 

SPS#_PCC_FULL_DEPTH: This table contains data on full-depth repair of PCC surfaces that 

occurred prior to the application of an overlay on SPS-6, -7, and -9 test sections. 

66 
SPS#_PCC_JOINT_RESEAL: This table contains data on joint resealing operations that 

occurred prior to the application of an overlay on SPS-6, -7, and -9 test sections. 

SPS#_PCC_PART_DEPTH: This table contains data on partial-depth patching of PCC 

surfaces that occurred prior to the application of an overlay on SPS-6, -7, and -9 test sections. 

SPS#_SUBDRAINAGE: This table contains data on the process of retrofitting subgrade 

drainage capacity within SPS-6, -7, and -9 test sections prior to the application of a rehabilitative 

overlay. 

SPS#_TRANSFER_EFFICIENCY: This table contains data on the load-transfer efficiency of 

transverse joints within SPS-6, -7, and -9 test sections following the load-transfer restoration 

process, but prior to the placement of an overlay.

SPS#_UNDERSEALING: This table contains general undersealing data for work done on 

SPS-6 and -7 test sections prior to the application of a rehabilitative overlay. 

SPS#_PCC_JOINT_DATA: This table contains construction data on joints within the test

section, including skew, dowel spacing, joint forming and saw-cutting, sealant, etc. SPS-2 and -8 

experiments have entries in this table.

SPS#_PCC_MIXTURE_DATA: This table contains construction data for the mixture for each 

PCC layer of the test section, including mix design, admixture information, aggregate 

composition and durability test results, and gradation. SPS-2 and -8 experiments have entries in 

this table. 

SPS#_PCC_PLACEMENT_DATA: This table contains construction data for each PCC layer 

in the test section, including concrete mix plant, paver, and spreader information; and dowel 

placement, vibration, finishing, curing, and texturing data. SPS-2 and -8 experiments have 

entries in this table. 

SPS#_PCC_PROFILE_DATA: This table contains information on the profiling and grinding 

of PCC surface layers of SPS-2 and -8 test sections. 

SPS#_PMA_DENSITY_PROFILE: This table contains PMA-bound layer nuclear density 

measurements and profilograph data. The densities of ATB, binder, surface, and friction are 

courses that are included. SPS-1 and -8 experiments have entries in this table. 

SPS#_AC_PATCHES: This table contains AC patching data collected at test sections in the 

SPS-5 and -9 experiments. This information is on patching that occurred in preparation for the 

applied AC overlay and was typically collected by the State highway agency or a representative 

of the regional support contractor. 

SPS#_MILLED_SECTIONS: This table contains data on milling operations that occurred at 

some SPS-5 and -9 test sections in preparation for AC overlays. The table contains information 

67 
on the equipment, layer delamination, milled thickness measurements, and other observations of

the process. 

SPS#_RUT_LEVEL_UP: This table contains data on applications of leveling treatments to 

correct severe rutting on SPS-5 and -9 test sections prior to the application of a PMA overlay. 

11.4 TABLES SPECIFIC TO INDIVIDUAL EXPERIMENTS 

The following tables are experiment-specific. The fourth character of the prefix indicates the 

number of the SPS experiment for which data are included in that table. 

SPS2_PCC_FULL_DEPTH: This table contains full-depth repair data for SPS-2 (study of 

structural factors for rigid pavements) test sections, including information on patching, slab 

replacement, load-transfer devices, reinforcing steel, concrete properties, finishing and curing 

methods, etc. 

SPS2_PCC_STEEL: This table contains information on the reinforcing steel used in each PCC 

layer of the SPS-2 test section. 

SPS3_CHIP: This table contains chip seal aggregate and sealant properties, placement data, 

surface preparation, and other information for SPS-3 test sections with chip seal maintenance 

treatments. 

SPS3_CHIP_EQUIP: This table contains information on all equipment used in applying chip 

seal maintenance treatments to SPS-3 test sections. 

SPS3_CRACK: This table contains information on surface preparation, environmental 

conditions, sealant properties, equipment used, and application processes for SPS-3 test sections 

with crack sealing maintenance treatments. 

SPS3_ROLLER: This table contains information on the roller equipment used in chip seal 

applications to SPS-3 test sections. 

SPS3_SLURRY: This table contains asphalt and aggregate properties, application rates, surface 

preparation, environmental conditions, etc., for SPS-3 test sections with slurry seal maintenance 

treatments. 

SPS3_SLURRY_EQUIP: This table contains information on all equipment used in slurry seal 

applications to SPS-3 sections. 

SPS4_BENKELMAN_GENERAL: This table contains general information on Benkelman 

beam deflection tests conducted on SPS-4 test sections. Included are start and end times, dates, 

environmental conditions, etc. 

68 
SPS4_BENKELMAN_MEASURE: This table contains the results of Benkelman beam 

deflection tests conducted on SPS-4 test sections, including the station and joint number where 

each test was conducted and the corresponding deflection measurements. 

SPS4_CONTROL_GENERAL: Each SPS maintenance test project included a control section 

on which no maintenance was to be performed unless required as a safety measure. This table 

contains general information on the characteristics of the control section for each SPS-4 project. 

SPS4_CONTROL_LONG: This table contains the width of the longitudinal joint opening for 

each SPS-4 control section. 

SPS4_CONTROL_RANDOM: This table contains the widths of the surface cracks for each 

SPS-4 control section. 

SPS4_CONTROL_SHOULDER: This table contains the width of the shoulder joint for each 

SPS-4 control section. 

SPS4_CONTROL_TRANS: This table contains the widths of the transverse joints for each 

SPS-4 control section. 

SPS4_CRACK_SEAL_GENERAL: This table contains information on joint and crack sealing 

operations at SPS-4 test sections. 

SPS4_CRACK_SEAL_PVMT: This table contains information on sealant properties, 

temperatures, application techniques, backer rod, removal of old sealant, cleaning, etc., 

associated with the sealing of transverse and longitudinal joints within SPS-4 test sections. 

SPS4_CRACK_SEAL_PVMT_MEAS: This table contains joint seal measurements, including 

backer rod depths, for all sealing work on transverse and longitudinal joints within SPS-4 test 

sections. 

SPS4_CRACK_SEAL_RAND: This table contains information on sealant properties, 

temperatures, application techniques, backer rod, removal of old sealant, cleaning, etc., 

associated with the sealing of cracks within SPS-4 test sections. 

SPS4_CRACK_SEAL_RAND_MEAS: This table contains crack sealing measurements, 

including backer rod depths, for all sealing work on cracks within SPS-4 test sections. 

SPS4_CRACK_SEAL_SH: This table contains information on sealant properties, temperatures, 

application techniques, backer rod, removal of old sealant, cleaning, etc., associated with the 

sealing of longitudinal joints at the shoulders of SPS-4 test sections. 

SPS4_CRACK_SEAL_SH_MEAS: This table contains joint seal measurements, including 

backer rod depths, for all sealing work on longitudinal shoulder joints of SPS-4 test sections. 

69 
SPS4_DYNAFLECT_GENERAL: This table contains general information on Dynaflect®

deflection testing that was conducted on SPS-4 test sections. 

SPS4_DYNAFLECT_MEASURE: This table contains the point locations (stationing) and 

Dynaflect sensor deflections recorded at each joint or crack within the SPS-4 section that was 

tested. 

SPS4_FWD_MEASUREMENTS: This table contains general information on FWD deflection 

testing that was conducted on SPS-4 test sections. The table name is misleading since the actual 

test results are stored offline. 

SPS4_TRANSIENT_GENERAL: This table contains general information on transient dynamic 

response testing that was conducted on SPS-4 test sections. 

SPS4_TRANSIENT_MEASURE: This table contains the point locations (stationing) and 

transient dynamic response test results for each joint or crack within the SPS-4 section that was 

tested. 

SPS4_UNDERSEAL_GENERAL: This table contains general undersealing data, including 

information on the cement, fly ash, water source, hole installation and volume, etc. 

SPS4_UNDERSEAL_INIT_GROUT: This table contains information on the initial grouting 

application process. 

SPS4_UNDERSEAL_PRES_GROUT: This table contains information on the pressure 

grouting application process. 

SPS4_UNDERSEAL_REGROUT: This table contains information on the regrouting 

application process. 

SPS6_CRACK_SEAT_PCC: This table contains PCC crack-and-seat data collected at test 

sections in the SPS-6 experiment (rehabilitation of PCC pavements). This information is on 

crack-and-seat operations that occurred in preparation for overlays on PCC pavements and was 

typically collected by the State highway agency or a representative of the regional support 

contractor. 

SPS6_SAW_AND_SEAL: This table contains data on joint sawing and sealing operations that 

occurred prior to the application of an overlay on SPS-6 test sections. 

SPS7_DELAMINATION: This table contains general information on the removal/cleaning of 

the PCC surfaces of SPS-7 test sections in preparation for PCC overlay. 

SPS7_MILLING: This table contains data on milling operations that occurred at some SPS-7 

test sections in preparation for PCC overlay. 

70 
SPS7_PCCO_JOINT_DATA: This table contains construction data on joints in the PCC

overlay of SPS-7 test sections, including skew, load-transfer method, joint forming and sawcutting, sealant, etc. 

SPS7_PCC_OVERLAY: This table contains information on the placement operations of PCC 

overlays on SPS-7 test sections, including air temperatures, curing, sawing, grouting, and 

texturing. 

SPS7_REFLECTIVE_CRACK: This table contains the methods used for controlling reflective 

cracking on SPS-7 test sections after a PCC overlay. 

SPS7_REMOVAL_CLEANING: This table contains the methods and dates for surface 

removal/cleaning of the PCC surfaces of SPS-7 test sections prior to a PCC overlay. 

SPS9_DIAMOND_GRIND: This table contains information on the diamond grinding of the 

PCC surface of SPS-9 test sections prior to overlay. 

SPS9_PMA_DENSITY: This table, which is unique to SPS-9 test sections, contains PMA layer 

density data used for construction control. 

SPS9_PMA_MIX_DES_PROP: This table contains the design mixture properties for PMA 

layers of SPS-9 test sections. 

SPS9_PMA_MIXTURE_PROP: This table contains the mixture properties (determined from

laboratory testing) for PMA layers of SPS-9 test sections. 

SPS9_PMA_PLACEMENT_INFO: This table contains the sectionwide properties of the 

asphalt lay-down process for each SPS-9 project, including surface preparation, asphalt plant 

information, equipment information, and haul time and distances for each lift. 

SPS9_PMA_PLACEMENT_LAYER: This table contains the sectionwide properties of the 

asphalt lay-down process for SPS-9 sections, including lift thicknesses, tack coat information, 

and transverse joint locations. 

SPS9_PMA_PROFILE: This table contains profilograph measurement results for the AC 

overlay layer of each SPS-9 test section. This information was used for construction control. 

SPS9_SP_PMA_AC_PROPERTIES: This table, which is unique to SPS-9 test sections, 

contains PMA-bound layer Superpave asphalt cement properties. 

SPS9_SP_PMA_AGGREGATE_PROP: This table, which is unique to SPS-9 test sections, 

contains PMA-bound layer Superpave aggregate properties. 

SPS9_SP_PMA_MIXTURE_PROP: This table, which is unique to SPS-9 test sections, 

contains PMA-bound layer Superpave mixture properties. 

71 
SPS9_SUBGRADE_PREP: This table contains subgrade preparation data collected on 

construction data sheets, including information on compaction and stabilization. 

72 
CHAPTER 12. TRAFFIC MODULE 

The Traffic (TRF) module contains agency estimates, computed annual estimates of traffic 

volumes and loads, and supporting measurement information on the traffic characteristics in the 

LTPP test section lane. In the development of the LTPP program, participating highway agencies 

have agreed to provide traffic monitoring measurements for test sections in their jurisdiction. 

Traffic volume and loading estimates for time periods prior to the start of LTPP traffic 

monitoring in 1990 are referred to as “Historical” data, while the information derived from the 

installed monitoring equipment (or from estimates for those test sections that had no monitoring 

equipment until some time after 1990) is known within the program as “Monitoring” data. Table 

names within the TRF module reflect the source of the data stored within them. 

The LTPP traffic data collection plan has been developed to balance the needs of the research 

program and the constraints of existing technology and finite highway agency resources. The 

plan recognizes several major principles: 

• Traffic loading estimates should be the result of onsite measurements wherever possible. 

• Data from all LTPP locations should be treated consistently in collection, submission, 

review, and aggregation, without modification to reflect “expected” values. 

• Data included in the database should follow the principle of “truth in data“. ” The term

“truth in data” has been defined to include the following: 

o Practices and conditions under which the data have been collected must be reported. 

o Editing of traffic data must be documented and a record of the original (unedited)

data must be retained. 

o Estimates of the variability in the data must be made and reported. 

Traffic data collection for LTPP sections is a State/Provincial responsibility. Data collection 

plans from each agency have integrated the LTPP requirements and individual State/Provincial 

practices. This has resulted in site-to-site variability in the amount and type of data being 

collected for the LTPP program that greatly exceeds the variability found in the other data 

modules. 

12.1 IMPORTANT FIELDS 

Common fields unique to the TRF tables that can be used to link related data in associated tables 

to each other include VEHICLE_CLASS, AXLE_GROUP, CLASS_COUNT_BEGIN_DATE, 

and WIM_AVC_CALIB_DATE. 

VEHICLE_CLASS refers to the FHWA 13-bin vehicle classification system (table 4). (Note 

that athough the classification system is named 13-bin for historical reasons, it has 15 

categories.) This field can be used to link the number of vehicles weighed within each class 

(from the TRF_HIST_WEIGHT_DATA table) to the distribution of axle group weights for these 

classes (from the TRF_HIST_WEIGHT_AXLES table). This field is also used within 

TRF_HIST_CLASS_DATA to indicate the number of vehicles within each category that were 

counted during classification surveys. The similar VEHICLE_CLASS field within 

73 
TRF_MONITOR_AXLE_DISTRIB can be used to link data to the TRF_HIST tables, but only 

for the truck categories (classes 4 through 14) since motorcycles, automobiles, and light trucks 

are not present in weigh-in-motion (WIM) monitoring data. 

Table 4. FHWA 13-bin vehicle classification system. 

Vehicle Class Description

1 Motorcycles

2 Passenger cars

3 Other 2-axle, 4-tire single-unit vehicles 

4 Buses

5 2-axle, 6-tire single-unit trucks 

6 3-axle single-unit trucks 

7 4- or more axle single-unit trucks 

8 4- or less axle single-trailer trucks 

9 5-axle single-trailer trucks

10 6- or more axle single-trailer trucks 

11 5- or less axle multi-trailer trucks 

12 6-axle multi-trailer trucks

13 7- or more axle multi-trailer trucks 

14 Unclassifiable

15 Partial vehicles, including offscale or lane-changing vehicles 

AXLE_GROUP is a variable that defines the type of axle or axle group (single, tandem, triple, 

or quad). The variable is used within the TRF_HIST_WEIGHT_AXLES and 

TRF_MONITOR_AXLE_DISTRIB tables. Note that steering axle groups are not recorded 

separately from other single axles in this table. 

CLASS_COUNT_BEGIN_DATE may be used to relate information on a specific historical 

traffic classification count that is stored within the TRF_HIST_CLASS_MASTER table with the 

actual count data that is stored in TRF_HIST_CLASS_MASTER. 

WIM_AVC_CALIB_DATE must be used when relating the specific calibration factors found 

within TRF_CALIBRATION_AVC and TRF_CALIBRATION_WIM to the list of installed 

traffic monitoring equipment found within TRF_EQUIPMENT_MASTER. 

12.2 TRF TABLES 

TRF_BASIC_INFO: This table contains basic information about the location of the section and 

the roadway on which it is located. 

TRF_CALIBRATION_AVC: This table contains information on the calibration of automated 

vehicle classification (AVC) equipment installed at a test section. 

TRF_CALIBRATION_WIM: This table contains information on the calibration of weigh-inmotion (WIM equipment installed at a test section. 

74 
TRF_EQUIPMENT_MASTER: This table contains information about equipment (both AVC 

and WIM) in place during a calibration event. 

TRF_EXTRACTOR: This table is used for internal database functions.

TRF_HIST_CLASS_DATA: This table contains the results of vehicle classification counts that 

were taken by the State/Provincial agency prior to the start of LTPP traffic monitoring and were 

used to estimate vehicle distributions at the site. These counts were not necessarily taken at the 

site itself.

TRF_HIST_CLASS_MASTER: This table contains the specifics of the classification counts 

that furnished data for TRF_HIST_CLASS_DATA. The CLASS_MASTER table also contains

the total volumes recorded during each count. 

TRF_HIST_EST_ESAL: This table contains estimates of 80-kN (18-kip) equivalent single-axle 

loads (ESALs) at the section for each year from construction (or 1965, whichever is later) to its 

inclusion in the LTPP program. 

TRF_HIST_VOLUME_COUNT: This table contains the results of vehicle volume counts that 

were taken by the State/Provincial agency prior to the start of LTPP traffic monitoring and were 

used to estimate traffic volumes at the site. These counts were not necessarily taken at the site 

itself.

TRF_HIST_WEIGHT_AXLES: This table contains the results of truck weighing sessions that 

were conducted by the State/Provincial agency prior to the start of LTPP traffic monitoring and 

were used to estimate traffic loading at the site. These counts were not necessarily taken at the 

site itself.

TRF_HIST_WEIGHT_DATA: This table contains the number of vehicles weighed during the 

sessions in which TRF_HIST_WEIGHT_AXLES information was extracted. 

TRF_HIST_WEIGHT_MASTER: This table contains all general information on the roadway 

and the equipment used for historical truck weighing sessions. 

TRF_LIBRARIAN_INDEX: This table is used for internal database functions. 

TRF_MONITOR_AADT: This table contains information about the traffic characteristics of 

the LTPP section or project. This table contains estimates of total and truck annual average daily 

traffic (AADT)for the road and for the LTPP lane. This table also summarizes the amount of 

monitoring data used to create these estimates. Since the LTPP program requires only monitoring 

of a single lane in which the test section(s) is located, this table will be removed from the 

database in the future. 

TRF_MONITOR_AXLE_DISTRIB: This table contains the number of axles measured in each

weight range for each axle group (single, tandem, triple, and quad). This information is obtained

75 
from weigh-in-motion (WIM equipment installed at or near the test section. Note that steering 

axle weight distributions are not recorded separately from other single axles in this table. 

TRF_MONITOR_BASIC_INFO: This table contains summary information concerning the 

extent of data collection and site characteristics on a yearly basis. 

TRF_MONITOR_LTPP_LN: This table contains information on the amount of data collected 

on a vehicle class basis and the estimated annual volumes of trucks and axles associated with that 

data for the LTPP lane only. 

TRF_MON_EST_ESAL: This table contains an annual estimate of the number of 80-kN (18-

kip) ESALs in the study lane and estimates of truck and total vehicle volumes. The data within 

this table are for the period from 1990 until the test section was instrumented with monitoring 

equipment. The estimates are supplied by the highway agency. 

76 
CHAPTER 13. MATERIALS TESTING MODULE 

13.1 BACKGROUND 

Extensive field tests, materials sampling, and laboratory testing are conducted on LTPP test 

sections to: 

• Verify and document the as-constructed pavement structure of LTPP test sections. 

• Provide the basic engineering material properties of the pavement structure that support a 

wide variety of performance analyses. 

• Provide a measure of the variation in the pavement structure and material properties. 

The original materials characterization scheme was based on materials testing and parameters 

that existed in the late 1980s. Updates to a few tests, most notably the resilient modulus of AC 

materials, were made in the 1990s. Overall, the intention of the LTPP program is to focus on 

materials tests in common use at the initiation of the project, so that upon completion, a full suite 

of results will be available for the entire timespan. 

The LTPP program developed materials sampling and testing protocols primarily based on inplace material samples from pavement structures, although for some tests on SPS sections or 

GPS overlay sections, materials were sampled during construction. These protocols are 

documented in SHRP-LTPP Interim Guide for Laboratory Materials Handling and Testing and 

SHRP-LTPP Guide for Field Materials Sampling, Testing, and Handling. In addition, materials 

sampling and testing guidelines were developed for each SPS experiment. A list of these 

guidelines is presented in appendix A. 

The LTPP materials sampling and testing program began on GPS test sections accepted into the 

program before 1990. An initial round of sampling and testing was conducted in 1989. LTPP 

contractors conducted the field materials sampling and testing and laboratory testing for these 

sections. For SPS sections and GPS overlay sections, the respective highway agency is 

responsible for most materials testing. Resilient modulus and associated testing of hot-mix 

asphalt (HMA) materials and the coefficient of thermal expansion of PCC materials are 

conducted by LTPP-contracted laboratories. 

13.2 MATERIALS TEST TYPES 

A list of typical materials tests, test designations, and protocols are shown in table 5. The test 

designation is used for database table names. The tests actually conducted on a test section are 

dependent on the type of materials, the thickness of the material layers, and the type of pavement 

layer. Test requirements also vary according to the objectives of the experiment to which the 

section is assigned. In some cases, a layer may not have been thick enough to meet testing 

requirements for bound materials or sufficient quantities of materials could not be obtained in 

order to conduct a test. 

LTPP Database 

Tip!

Perform an evaluation of data availability. Do not assume that all planned

materials tests are available. 

77 
Table 5. Materials testing designations and protocols. 

Material Test 

Designation Name Protocol

Asphalt Concrete AC01 Core Examination and Thickness P01

Asphalt Concrete AC02 Bulk Specific Gravity P02

Asphalt Concrete AC03 Maximum Specific Gravity P03

Asphalt Concrete AC04 Asphalt Content (Extracted) P04

Asphalt Concrete AC07(1) Resilient Modulus, Tensile Strength, and

Creep P04 

Asphalt Concrete SP01(1) Gyratory Compaction (4)

Asphalt Concrete SP02(1) Volumetric and Gravimetric Properties of 

Superpave Mixes 

(4)

Extracted Aggregate From Asphalt 

Concrete

AG01 Specific Gravity of Coarse Aggregate P11 

Extracted Aggregate From Asphalt 

Concrete

AG02 Specific Gravity of Fine Aggregate P12 

Extracted Aggregate From Asphalt 

Concrete

AG04 Gradation of Aggregate P14 

Extracted Aggregate From Asphalt 

Concrete

AG05(2) Fine Aggregate Particle Shape P14A 

Asphalt Cement AE01 Abson Recovery P21 

Asphalt Cement AE02 Penetration at 77 °F and 115 °F P22 

Asphalt Cement AE03 Specific Gravity at 60 °F P23 

Asphalt Cement AE04 Viscosity at 77 °F P24 

Asphalt Cement AE05 Viscosity at 140 °F and 275 °F P25 

Asphalt Cement AE07 Dynamic Shear Rheometer (DSR) Test (4)

Asphalt Cement AE08 Superpave Direct Tension (DT) Test (4)

Asphalt Cement AE09 Bending-Beam Rheometer (BBR) Test (4)

Bound/Treated Base and Subbase TB01 Identification and Description of Treated

Material and Type of Treatment P31 

Bound/Treated Base and Subbase TB02 Compressive Strength of Other Than Asphalt

Treated Material P32 

Unbound Granular Base and Subbase UG01 Particle Size Analysis P41

Unbound Granular Base and Subbase UG02 Washed Sieve Analysis P41 

Unbound Granular Base and Subbase UG04 Atterberg Limits P43

Unbound Granular Base and Subbase UG05 Moisture-Density Relations P44 

Unbound Granular Base and Subbase UG07 Resilient Modulus P46

Unbound Granular Base and Subbase UG08 Classification and Description P47 

Unbound Granular Base and Subbase UG09 Permeability of Granular Base/Subbase P48

Unbound Granular Base and Subbase UG10 Natural Moisture Content P49 

Subgrade SS01 Sieve Analysis P51

Subgrade SS02 Hydrometer Analysis P42 

Subgrade SS03 Atterberg Limits P43 

Subgrade SS04 Classification and Description P52 

Subgrade SS05 Moisture-Density Relations P55

78 
Table 5. Materials testing designations and protocols (continued). 

Material Test 

Designation Name Protocol

Subgrade SS06 Determination of Modulus of Subgrade Reaction 

by Nonrepetitive Static Plate Load Test P58 

Subgrade SS07 Resilient Modulus P46

Subgrade SS09 Natural Moisture Content P49

Subgrade 

SS11(3)

Measurement of Hydraulic Conductivity of

Saturated Porous Material Using a Flexible Wall 

Permeameter 

P57 

Subgrade SS12(3) Expansion Index P60 

Portland Cement Concrete PC01 Compressive Strength P61 

Portland Cement Concrete PC02 Splitting Tensile Strength P62

Portland Cement Concrete PC03 Coefficient of Thermal Expansion P63 

Portland Cement Concrete PC04 Static Modulus of Elasticity P64

Portland Cement Concrete PC05 Density of PCC P66 

Portland Cement Concrete PC06 Core Examination and Thickness P66 

Portland Cement Concrete PC07 Interface Bond Strength P67 

Portland Cement Concrete PC08(3) Air Content of Hardened Concrete P68

Portland Cement Concrete PC09 Flexural Strength P69 

SPS-3 and -4 SC01 Tests on Emulsified Asphalts (4)

SPS-3 and -4 SC02 Plastic Fines in Graded Aggregates by Use of 

Sand Equivalency Test

(4)

SPS-3 and -4 SC03 Testing Crushed Stone for Single Bituminous

Surface Treatments 

(4)

SPS-3 and –4 SC04 Determination of Flakiness Index of Aggregates (4)

SPS-3 and -4 SC05 Testing of Slurry Seal (4)

SPS-3 and -4 

SC06 

Measurement of Excess Asphalt in Bituminous

Mixtures by Use of Loaded Wheel and Sand 

Cohesion 

(4)

SPS-3 and -4 SC07 Wet Stripping Test for Cured Slurry Seal Mixes (4)

SPS-3 and -4 SC08 Determination of Slurry System Compatibility (4)

SPS-3 and -4 SC09 Mixing, Setting, and Water-Resistance Test to

Identify Quick-Set Emulsified Asphalts 

(4)

SPS-3 and -4 SC10A Aggregate Gradation of Chip Seals (4)

SPS-3 and -4 SC10B Aggregate Gradation of Slurry Seals (4)

SPS-3 and -4 SC11 Chip Seal Mix Design (4)

SPS-3 and -4 SC12 Determination of Asphalt Content From Slurry 

Seal Sample 

(4)

SPS-3 and -4 SC13 Polish Value of Chip Seal Aggregates (4)

SPS-3 and -4 CS01 Properties of Hot-Poured Joint Sealants (4)

SPS-3 and -4 CS02 Properties of Silicone Joint Sealants (4)

Notes: 

1 Data are limited at this time; more expected in the future. 2 Test is conducted by the National Aggregates Association Joint Research Laboratory. Data are not available for 

all test sections. 3 Data are limited; no more data expected. 4 Certain tests developed for experiments not begun under the LTPP program (SPS-3, -4, and -9) were not

conducted according to an LTPP protocol.

79 
13.3 IMPORTANT FIELDS 

In addition to the fields described in the course of outlining the sampling and layering

information tables, there are several other fields common to many tables in the Materials Testing 

(TST) module. While they are not critical to understanding the relational structure of the module, 

they do provide additional information to the analyst. 

FIELD_SET identifies materials sampled during visits to a site as related to construction events.

In theory, the FIELD_SET number should be incremented for each day that materials sampling 

and testing were conducted. In practice, the FIELD_SET number can span a period of time

during construction events. Material samples from GPS test sections are typically obtained 

during the first site visit after investigations to confirm the pavement structure. If a rehabilitation 

event is performed on a GPS test section, such as an overlay, material samples from the overlaid 

pavement structure will be assigned a new FIRLD_SET number. On SPS sites, assignment of a 

FIELD_SET number is more complicated since construction of multiple layers within a single 

construction event can occur. For SPS projects starting with a new or reconstructed pavement 

structure (i.e., SPS-1, -2, -8, and some -9’s), FIELD_SET = 1 will encompass the time until the 

final surface layer is completed. On SPS maintenance and rehabilitation projects, FIELD_SET =

1 typically represents materials sampling and testing prior to application of the maintenance and 

rehabilitation treatment. On a given test section, FIELD_SET begins at 1 and is incremented for 

each site visit at which material samples were obtained. As such, FIELD_SET can be used as a 

surrogate for the actual date of sampling in identifying samples from a single section of 

approximately the same age. 

TEST_NO is a code field of the type TEST_NO that indicates where in the section the sample 

was obtained. As such, TEST_NO can be used as a surrogate for the actual longitudinal and 

transverse location of the sampling when identifying test results from adjacent material samples 

at a test section. In addition, some tests conducted on bulk samples had to be conducted on a 

combination of materials sampled at different ends of the section or, in some cases, at different 

sections at an SPS project to meet the minimum weight requirements of the test. Certain values 

of the code TEST_NO are used to identify such conditions. Material samples obtained at an 

LTPP test section are typically obtained from either just before the beginning of the section (the 

“approach end”) or just after the end of the test section (the “leave end”). Sometimes samples are 

obtained from within the test section; however, this is kept to a minimum to avoid altering the 

performance characteristics of the section. 

SAMPLE_AREA identifies the area from which the material was sampled. During the 

development of the SPS materials sampling guidelines, the term “sample area” was coined to 

uniquely identify discrete areas at an SPS project from which material samples were obtained. 

Generally, the sample areas at an SPS project are numbered sequentially, starting with sample 

area 1 being assigned to the approach end of the first test section on the project. In addition, 

generally, the sample area at the approach end of a section has an odd number and the sample 

area at the leave end of a section has an even number. However, there is no way to verify that 

these generalizations hold true at any given SPS project without consulting the materials 

sampling plan specific to that project. This information is not available in the LTPP database at 

this time. The format of SAMPLE_AREA varies from table to table in the TST module (and 

80 
sometimes within a table as well). Generally, SAMPLE_AREA is formatted as “##”; however, 

sometimes it is formatted as “SA-##”, “SA##”, or even “S##”. 

LAB_CODE is a code field of the type LAB_CODE that identifies the laboratory that conducted 

the test of interest. As might be expected with a project as large as the LTPP program, many 

different laboratories contributed to the materials testing database. The individual laboratory that 

conducted any given test can be identified by the LAB_CODE field. LAB_CODE is actually a 

“smart code” in that the first two digits of a LAB_CODE are the same as the 

STATE_PROVINCE code of the State or Canadian Province in which the laboratory is located. 

COMMENTS_* are codes of the type COMMENT, so this value must be linked to the codes 

table for a description. Most of the test results tables share a unified set of comment codes. These 

comment codes document expected error conditions, such as insufficient sample size or 

specimen fracture during testing. These tables have multiple fields for storing these codes, taking 

the form of COMMENTS_* (e.g., COMMENTS_1, COMMENTS_2, etc.). For cases where no 

appropriate comment code is available, the COMMENT_OTHER field is used to store a text

comment. 

13.4 UNDERSTANDING THE MATERIALS TESTING DATA STRUCTURES 

Materials testing data are stored in the TST module. Additional materials characterization data 

are stored in the INV, RHB, MNT, and SPS# modules; however, those are based on construction 

history records supplied by the highway agency and are of unknown reliability. 

13.4.1 Test Results Tables 

Tables containing the results for specific tests can be identified based on the test designations 

shown in table 5. For example, data resulting from test AC03 is stored in a table named 

“TST_AC03”. Some subgrade and unbound base layer tests that were conducted according to the 

same protocol, but which have different test designations, are stored in tables that have a name

reflecting both test designations. For example, data resulting from test designations SS02 and 

UG03 are located in TST_SS02_UG03. 

Some tests, such as the resilient modulus tests, generate more complex results that are stored in a 

related series of tables. The following sections include a general outline of each test results table 

in the TST module. 

In each of the table descriptions below, the primary key is identified. The primary key is the list 

of fields required by the database to uniquely identify a single record in a particular table. 

13.4.1.1 AC Test Results Tables 

TST_AC01: This table contains the results of a visual examination of an AC core. It contains six 

fields (VISUAL_EXAM_1 through VISUAL_EXAM_6) for codes related to the observed 

properties of the core. These codes, of code type VISUAL_ACPC, encompass such items as 

stripping and degraded aggregate. An additional field (VISUAL_EXAM_OTHER) is reserved 

81 
for text comments for which no numeric codes were reserved. In addition, the height of the core 

is stored in the CORE_AVG_THICKNESS field. The primary key consists of the 

STATE_CODE, SHRP_ID, FIELD_LAYER_NO, FIELD_SET, TEST_NO, and LOC_NO 

fields. Although only STATE_CODE, SHRP_ID, FIELD_LAYER_NO, and LOC_NO are 

required to uniquely identify a record. 

The FIELD_LAYER_NO field should not be confused with LAYER_NO as used elsewhere in 

the TST module. Field layering, as the name suggests, is assigned during the field visit and is 

often modified at the regional office after inventory and materials testing data are reviewed. To 

obtain the “true” layer number, this table must be linked to TST_AC01_LAYER (described 

below) using the STATE_CODE, SHRP_ID, FIELD_SET, and FIELD_LAYER_NO fields. 

(FIELD_SET is required because field layering may be assigned differently on separate field 

visits.) 

TST_AC01_LAYER: This table contains the information necessary to convert the field layer 

numbers recorded in TST_AC01 to “true” layer numbers as used in the rest of the module. In 

addition, this table contains the thickness of each “true” layer in so far as it can be determined 

from the core. This thickness is stored in the LAYER_THICKNESS field. The primary key 

consists of the STATE_CODE, SHRP_ID, FIELD_LAYER_NO, FIELD_SET, TEST_NO, 

LAYER_NO, and LOC_NO fields. 

TST_AC02: This table contains bulk specific gravity test results from AC cores. Calculated bulk 

specific gravity is stored in the BSG field (no intermediate results are included). In addition, 

percent moisture absorption is available from the WATER_ABS field. Some specimens were 

paraffin-coated, and this is indicated by the value of the PARAFFIN_COAT field. The primary 

key consists of the STATE_CODE, SHRP_ID, FIELD_SET, LAYER_NO, TEST_NO, and 

LOC_NO fields, although STATE_CODE, SHRP_ID, and SAMPLE_NO should be all that is 

necessary to uniquely identify a record. 

TST_AC03: This table contains theoretical maximum specific gravity test results from AC

cores. Calculated maximum specific gravity is stored in the MAX_SPEC_GRAVITY field (no 

intermediate results are included). The primary key consists of the STATE_CODE, SHRP_ID, 

LAYER_NO, FIELD_SET, TEST_NO, and LOC_NO fields, although STATE_CODE, 

SHRP_ID, and SAMPLE_NO should be all that is necessary to uniquely identify a record. 

TST_AC04: This table contains extracted asphalt content test results from AC cores using 

trichloroethylene as a solvent. Calculated asphalt content is stored in the 

ASPHALT_CONTENT_MEAN field (no intermediate results are included). The primary key 

consists of the STATE_CODE, SHRP_ID, LAYER_NO, FIELD_SET, TEST_NO, and 

LOC_NO fields, although STATE_CODE, SHRP_ID, and SAMPLE_NO should be all that is 

necessary to uniquely identify a record. 

TST_AC05: This table contains moisture susceptibility test results from laboratory-compacted 

bulk asphalt specimens. There are only data for a limited number of sections from the SPS-1, -5, 

-8, and -9 projects. A user should first check for data availability before attempting to use this 

82 
data in analysis. The LTPP protocol for this test (P05) is primarily based on AASHTO T283, and 

the user should be familiar with the procedure before attempting to interpret the results. 

In essence, test AC05 evaluates the changes in indirect tensile strength in a bituminous mixture 

caused by water saturation. Six specimens are molded from bulk samples using Marshall, 

Hveem, or gyratory compaction (the type of compaction used is stored in the 

METHOD_OF_COMPACTION field). Three of these cores are subjected to vacuum saturation 

followed by freezing and warm water soaking cycles, while the other three are kept dry. All six 

specimens are then loaded to failure in indirect tension. The ratio of the average strength of the 

dry specimens to the conditioned specimens, called the tensile strength ratio (TSR), is stored in 

the TENSILE_STRENGTH_RATIO field. In addition, the ratio of the coefficient of variation of 

the strength of the dry specimens to the coefficient of variation of the strength of the conditioned 

specimens is stored in the RELATIVE_VARIATION_IN_STRENGTH field. 

TST_AC05 also contains several intermediate calculations for the six specimens. These 

calculations are stored in fields with names in the format {property name}_#_{C,U}, where the 

property name is the measured property (such as WIDTH or BSG), # is the name of the number, 

and {C,U} denotes whether the specimen is from the conditioned set or the unconditioned set. 

TST_AC05 also has a slight complication regarding sample numbers. The SAMPLE_NO field 

denotes the sample number of the bulk asphalt concrete from which the specimens were molded 

and SAMPLE_NO_#_{C,U} denotes the sample number assigned to the compacted specimens. 

Since these specimens were tested to failure, their individual sample numbers should not appear 

in any other table. 

The primary key consists of the STATE_CODE, SHRP_ID, LAYER_NO, FIELD_SET, 

TEST_NO, and LOC_NO fields, although STATE_CODE, SHRP_ID, and SAMPLE_NO 

should be all that is necessary to uniquely identify a record. 

TST_AC_MOIST_DAMAGE: This table contains data resulting from a visual evaluation of 

moisture damage to the field cores. Data exists for only a limited number of SPS-5 and -9 

sections. 

13.4.1.2 TST_AC07_V2_* Tables 

Test results from LTPP test AC07 are stored in four related tables. These results include resilient 

modulus, creep compliance, and the indirect tensile strength of AC core samples. “V2” in the 

table names indicates that these tests were conducted according to the second version of protocol 

P07 used by the LTPP program. The results from the first version of protocol P07 are considered 

unreliable and are not available in the standard data release. 

Test AC07 involves multiple tests on three specimens. The analytical procedures employ unusual 

data massaging, averaging, and outlier elimination methods to combine the results from these 

three specimens. While a full understanding of these analytical procedures is not a requirement 

for using the data, a basic understanding of the test procedure could prove to be useful. The test 

procedure is documented in LTPP Protocol P07: Test Method for Determining the Creep 

83 
Compliance, Resilient Modulus, and Strength of Asphalt Materials Using the Indirect Tensile 

Test Device and is illustrated by figure 9. Protocol P07 is also similar to AASHTO TP9-96 with 

regards to the creep compliance and indirect tensile strength portions. 

(1 record 

per test) 

Basic information for 

specimen 1 

Basic information for 

specimen 2 

Basic information for 

specimen 3 

Specimen 

1 

Specimen 

2 

Specimen 

3 

TST_AC07_V2_SPECIMEN_INFO

“Magic Box” Analysis Software 

Raw Data Raw Data Raw Data

Resilient Modulus at Temperature 1 

Basic Info Basic Info Basic Info

TST_AC07_V2_MR_SUM 

Resilient Modulus at Temperature 2 

Resilient Modulus at Temperature 3 

Creep Compliance at Temperature 1

TST_AC07_V2_CREEP_COMP_SUM 

Creep Compliance at Temperature 2

Creep Compliance at Temperature 3

TST_AC07_V2_IDT_SUM 

Indirect Tensile Strength at 

Temperature 1 

(3 records 

per test) 

(3 records 

per test) 

(1 record 

per test) 

Figure 9. Illustration of relationships among TST_AC07* tables. 

84 
TST_AC07_V2_SPECIMEN_INFO: This table is considered the master table for a 

TST_AC07_V2 submodule. Key fields in TST_AC07_V2_SPECIMEN_INFO include 

STATE_CODE, SHRP_ID, LAYER_NO, TEST_NO, and FIELD_SET. This table also includes 

the sample numbers for the three specimens used (SAMPLE_NO_*), thickness information for 

the specimens (THICKNESS_SPECIMEN_*), diameter information 

(DIAMETER_SPECIMEN_*), and bulk specific gravity test results (BSG_SPECIMEN_*). This 

table also contains the unique filenames for the output files generated by the analysis software. 

These files are stored offline, but may contain data of interest to some analysts. These data are 

stored in the CREEP_DATA_ANAL_FILE, MR_DATA_ANAL_FILE, and 

IDT_DATA_ANAL_FILE_* fields, where MR stands for “resilient modulus” and IDT stands 

for “indirect tensile strength.” 

TST_AC07_V2_MR_SUM: This table contains summary data for the resilient modulus tests. 

These data include computed values for three load cycles and average values. The three 

computed values are instantaneous resilient modulus, total resilient modulus, and Poisson’s ratio. 

The instantaneous resilient modulus is calculated using only the strain recovered during the 

unloading portion of the cycle, while the total resilient modulus includes the strain recovered 

during the 0.9-second “rest” portion of the cycle. In addition, there are fields containing a “used” 

Poisson’s ratio. This is an output of the analysis software to account for the fact that the test 

procedure sometimes yields unreasonable Poisson’s ratios. This table also contains the unique 

filenames for the three raw data files (one per specimen per test temperature) generated by the 

test data acquisition system and processed by the analysis software. They are stored offline. The 

primary key includes STATE_CODE, SHRP_ID, LAYER_NO, TEST_NO, FIELD_SET, and 

TEST_TEMPERATURE since this test is conducted at three different temperatures. 

TST_AC07_V2_CREEP_COMP_SUM: This table contains summary data for the creep 

compliance tests. Creep compliance is stored in the CREEP_COMP_*_SEC fields, where * is 

the time interval from the initiation of the test in which the creep compliance was calculated. 

These time intervals are 1, 2, 5, 10, 20, 50, and 100 seconds. In addition, the value of the 

Poisson’s ratio calculated using these data is stored in the CREEP_POISSON_CALC field. The 

CREEP_POISSON_USED field contains the value used in the computation as described in the 

preceding paragraph. In addition, the unique filenames for the three raw data files (one per 

specimen) are stored in the CREEP_COMP_DATA_FILE_SPECIMEN_* fields. The primary 

key includes STATE_CODE, SHRP_ID, LAYER_NO, TEST_NO, FIELD_SET, and 

TEST_TEMPERATURE since this test is conducted at three different temperatures. 

TST_AC07_V2_IDT_SUM: This table contains the summary data for the indirect tensile 

strength test. Indirect tensile strengths for the three specimens are stored in the 

IDT_SPECIMEN_* fields, while the average is stored in the IDT_AVERAGE field. The 

calculated Poisson’s ratio for this test is stored in the IDT_POISSON_CALC field, while the 

IDT_POISSON_USED field contains the value used in the computations as described in the 

discussion of TST_AC07_V2_MR_SUM. Several other fields for the initial tangent modulus, 

fracture energy, and failure strain exist; however, the data to populate them are not included in 

the standard release because the algorithms used by the analysis software are insufficiently 

documented, could not be reverse-engineered, and are suspect. The primary key includes 

85 
STATE_CODE, SHRP_ID, LAYER_NO, TEST_NO, FIELD_SET, and

TEST_TEMPERATURE, although this test is only conducted at one temperature. 

13.4.1.3 Asphalt Cement Tables 

TST_AE01: This table contains the results of the extraction of asphalt cement from field cores 

by the Abson method. The two data fields are MASS_OF_RECOVERED_BITUMEN, which 

contains the mass in grams of the recovered asphalt cement, and 

ASH_CONTENT_OF_BITUMEN, which contains the percent ash content of the recovered 

asphalt cement. Generally, this test is conducted to provide material for the other AE series tests, 

although the sample number for the input material is the same as the sample number for the 

output material. The primary key consists of the STATE_CODE, SHRP_ID, LAYER_NO, 

FIELD_SET, TEST_NO, and LOC_NO fields, although STATE_CODE, SHRP_ID, and 

SAMPLE_NO should be all that is necessary to uniquely identify a record. 

TST_AE01S is quite similar to TST_AE01; however, it was developed to accommodate data 

from SPS-3 projects that were tested according to different protocols. The only significant 

difference from the analyst’s perspective is that the moisture content of the field core is also 

included in the MOISTURE_IN_MIXTURE field. 

TST_AE02: This table contains the results of penetration tests conducted on extracted asphalt 

cements at 25 °C (77 degrees Fahrenheit (°F)) and 68 °C (155 °F) (although plant-sampled 

asphalt cements were tested for some SPS projects (see the discussion on sample numbers in 

section 13.4.2)). The three data fields are PENETRATION_77_F, PENETRATION_155_F, and 

PENETRATION_INDEX. The primary key consists of the STATE_CODE, SHRP_ID, 

LAYER_NO, FIELD_SET, TEST_NO, and LOC_NO fields, although STATE_CODE, 

SHRP_ID, and SAMPLE_NO should be all that is necessary to uniquely identify a record. 

TST_AE02S: This table contains data for SPS-3 projects only. Penetration was performed at 

only one test temperature, typically 25 °C (77 °F). The test temperature is stored in the 

TEST_TEMPERATURE field and the penetration is stored in the AVERAGE_PENETRATION 

field. 

TST_AE03: This table contains the results of specific gravity tests on extracted asphalt cement. 

Calculated specific gravity is stored in the only data field (SPECIFIC_GRAVITY). The primary 

key consists of the STATE_CODE, SHRP_ID, LAYER_NO, FIELD_SET, TEST_NO, and 

LOC_NO fields, although STATE_CODE, SHRP_ID, and SAMPLE_NO should be all that is 

necessary to uniquely identify a record. 

TST_AE04: This table contains the viscosity of asphalt cements as measured using a cone-andplate viscometer. This test is conducted at a nominal temperature of 25 °C (77 °F). The data 

fields include viscosity and the corresponding shear rate for five surcharges (100, 300, 1000, 

3000, and 10,000 grams), and the fracture load and failure shear stress. Calculated specific 

gravity is stored in the only data field (SPECIFIC_GRAVITY). The primary key consists of the 

STATE_CODE, SHRP_ID, LAYER_NO, FIELD_SET, TEST_NO, and LOC_NO fields, 

86 
although STATE_CODE, SHRP_ID, and SAMPLE_NO should be all that is necessary to 

uniquely identify a record. This test is no longer conducted. 

TST_AE05: This table contains the results of kinematic viscosity testing at 135 °C (275 °F) and 

absolute viscosity testing at 60 °C (140 °F). The summary data fields are 

KINEMATIC_VISC_275_F and ABSOLUTE_VISC_140_F, although some intermediate 

calculations are also provided. The primary key consists of the STATE_CODE, SHRP_ID, 

LAYER_NO, FIELD_SET, TEST_NO, and LOC_NO fields, although STATE_CODE, 

SHRP_ID, and SAMPLE_NO should be all that is necessary to uniquely identify a record. 

TST_AE06S: This table contains the absolute viscosity of extracted asphalt cement from SPS-3 

projects. These data are similar to the absolute viscosity data stored in the TST_AE05 table. The 

test was conducted at a nominal temperature of 60 °C (140 oF). Absolute viscosity data are stored 

in the VACUUM_CAPILARY_VISC field and the test temperature is stored in the 

TEST_TEMPERATURE field. The primary key consists of the STATE_CODE, SHRP_ID, 

LAYER_NO, FIELD_SET, TEST_NO, and LOC_NO fields, although STATE_CODE, 

SHRP_ID, and SAMPLE_NO should be all that is necessary to uniquely identify a record. 

13.4.1.4 Tables on Aggregate in Asphalt Concrete 

TST_AG01: This table contains the bulk specific gravity and percent moisture absorption of 

extracted coarse aggregate from AC cores. These data are stored in the 

BSG_OF_COARSE_AGG and ABSORPTION_OF_COARSE_AGG fields. Some intermediate

calculations are also included. The primary key consists of the STATE_CODE, SHRP_ID, 

LAYER_NO, FIELD_SET, TEST_NO, and LOC_NO fields, although STATE_CODE, 

SHRP_ID, and SAMPLE_NO should be all that is necessary to uniquely identify a record. 

TST_AG02: This table contains the bulk specific gravity and percent moisture absorption of 

extracted fine aggregate from AC cores. These data are stored in the BSG_OF_FINE_AGG and 

ABSORPTION_OF_FINE_AGG fields. Some intermediate calculations are also included. The 

primary key consists of the STATE_CODE, SHRP_ID, LAYER_NO, FIELD_SET, TEST_NO, 

and LOC_NO fields, although STATE_CODE, SHRP_ID, and SAMPLE_NO should be all that 

is necessary to uniquely identify a record. 

TST_AG04: This table contains the gradation of extracted aggregate from AC cores. Gradation 

is determined by sieve analysis. The sieve set used consists of 37.5-mm (11⁄2-inch), 25.0-mm (1-

inch), 19.0-mm (3⁄4-inch), 12.5-mm (1⁄2-inch), 9.5-mm (3⁄8-inch), 4.75-mm (No. 4), 2.00-mm (No. 

10), 425-μm (No. 40), 180 μm (No. 80), and 75μm (No. 200) sieves. The percent passing each 

sieve is stored in a data field such as ONE_AND_HALF_PASSING for the 37.5-mm (11⁄2-inch)

sieve or NO_80_PASSING for the 180 μm (No. 80) sieve. The primary key consists of the 

STATE_CODE, SHRP_ID, LAYER_NO, FIELD_SET, TEST_NO, and LOC_NO fields, 

although STATE_CODE, SHRP_ID, and SAMPLE_NO should be all that is necessary to 

uniquely identify a record. 

TST_AG05: This table contains the fine aggregate shape test results for fine aggregate extracted 

from AC cores. Data include bulk specific gravity, percent moisture absorption, and 

87 
uncompacted void content, which are stored in the BSG, ABSORPTION, and 

UNCOMP_VOID_AVG fields, respectively. The primary key consists of the STATE_CODE, 

SHRP_ID, LAYER_NO, FIELD_SET, TEST_NO, and LOC_NO fields, although 

STATE_CODE, SHRP_ID, and SAMPLE_NO should be all that is necessary to uniquely 

identify a record. 

13.4.1.5 In Situ Tests 

TST_ISD_MOIST: This table contains in situ density and moisture content measurements using 

a nuclear density gauge. Up to four measurements of dry density (ISD_DRY_*), wet density 

(ISD_WET_*), and moisture content (ISMC_*), along with their respective averages 

(ISD_DRY_AVG, ISD_WET_AVG, ISMC_AVG) are stored in this table. The primary key 

consists of the STATE_CODE, SHRP_ID, FIELD_SET, LOC_NO, and 

DEPTH_TOP_STRATA fields. The DEPTH_TOP_STRATA field contains the depth (in inches) 

from the measuring surface to the pavement surface. 

13.4.1.6 PCC Test Results 

TST_PC01: This table contains the compressive strength of PCC cores (although for a few SPS 

projects, cylinders made from fresh PCC sampled during construction were tested (see the 

discussion of sample numbers in section 13.4.2 for information on how to determine the sample 

type)). Compressive strength is stored in the COMP_STRENGTH field and the observed fracture 

mechanism (a code of the type FRACTURE) is stored in the COMP_FRAC_OTHER field. 

Several other intermediate calculations, such as the length and diameter of the specimen, are also 

stored. The primary key consists of the STATE_CODE, SHRP_ID, LAYER_NO, FIELD_SET, 

LOC_NO, TEST_NO, and SAMPLE_NO fields, although STATE_CODE, SHRP_ID, and 

SAMPLE_NO should be sufficient to uniquely identify a specimen. 

TST_PC02: This table contains the splitting tensile strength of PCC cores and some cylinders 

(see discussion for TST_PC01). Tensile strength is stored in the TENSILE_STRENGTH field 

and the observed failure mechanism (a code of the type FRACTURE) is stored in the

TENSILE_STRENGTH_FRAC field. Several intermediate calculations, such as the length and 

diameter of the core, are also stored. The primary key consists of the STATE_CODE, SHRP_ID, 

LAYER_NO, FIELD_SET, LOC_NO, TEST_NO, and SAMPLE_NO fields, although 

STATE_CODE, SHRP_ID, and SAMPLE_NO should be sufficient to uniquely identify a 

specimen. 

TST_PC03: This table contains the coefficient of thermal expansion of PCC cores. The 

coefficient of thermal expansion is stored in the COEFF_THERMAL_EXPANSION field. In 

addition, a text description of the character of the aggregate type is included in the 

AGGR_TYPE_PCC field. The primary key consists of the STATE_CODE, SHRP_ID, 

LAYER_NO, FIELD_SET, LOC_NO, TEST_NO, and SAMPLE_NO fields, although 

STATE_CODE, SHRP_ID, and SAMPLE_NO should be sufficient to uniquely identify a 

specimen. 

88 
TST_PC04: This table contains the static modulus of elasticity of PCC cores. Elastic modulus is 

stored in the ELASTIC_MOD field, the Poisson’s ratio is stored in the POISSON_RATIO field, 

and unit weight is stored in the UNIT_WT field. The primary key consists of the 

STATE_CODE, SHRP_ID, LAYER_NO, FIELD_SET, LOC_NO, and TEST_NO fields, 

although STATE_CODE, SHRP_ID, and SAMPLE_NO should be sufficient to uniquely identify 

a specimen. 

TST_PC05: This table contains the density measurements for PCC cores. Bulk specific gravity, 

apparent specific gravity, density, and percent voids are stored in the 

BULK_SPECIFIC_GRAVITY_DRY, APPARENT_SPECIFIC_GRAVITY, 

DENSITY_OF_PCC, and PERCENT_VOIDS_IN_PCC fields, respectively. Several other 

intermediate calculations are also included in this table. The primary key consists of the 

STATE_CODE, SHRP_ID, LAYER_NO, FIELD_SET, LOC_NO, and TEST_NO fields, 

although STATE_CODE, SHRP_ID, and SAMPLE_NO should be sufficient to uniquely identify 

a specimen. 

TST_PC06: This table contains the visual examination notes for PCC cores. Six fields 

(VISUAL_EXAM_*) are provided for visual comments of the type VISUAL_ACPC (which 

means that these comments must be linked to the CODES table to retrive their meaning). A 

seventh field (VISUAL_EXAM_OTHER) is reserved for comments for which no comment 

codes were provided. In addition, this table also provides the thickness of the core, which is 

stored in the CORE_AVG_THICKNESS field. The primary key consists of the STATE_CODE, 

SHRP_ID, LAYER_NO, FIELD_SET, LOC_NO, and TEST_NO fields, although 

STATE_CODE, SHRP_ID, and SAMPLE_NO should be sufficient to uniquely identify a 

specimen. 

TST_PC07: This table contains the interface shear strength between two bonded PCC layers. 

This test is conducted on a core (including both layers). The maximum shear strength exhibited 

by the bond during testing of the core is stored in the SHEAR_BOND_STRENGTH field. 

Several intermediate calculations are also included in this table. The primary key consists of the 

STATE_CODE, SHRP_ID, LAYER_NO, FIELD_SET, LOC_NO, and TEST_NO fields, 

although STATE_CODE, SHRP_ID, and SAMPLE_NO should be sufficient to uniquely identify 

a specimen. 

TST_PC08: This table contains the air content of hardened PCC as determined by visual 

examination of core specimens. Air content is stored in the AIR_CONTENT field. These data 

exist for only a handful of SPS-2 and -8 projects. The primary key consists of the 

STATE_CODE, SHRP_ID, LAYER_NO, FIELD_SET, LOC_NO, and TEST_NO fields, 

although STATE_CODE, SHRP_ID, and SAMPLE_NO should be sufficient to uniquely identify 

a specimen. 

TST_PC09: This table contains the flexural strength of PCC beams that were poured from

materials sampled at the time of construction. Because of the requirement for sampling during 

construction, data for this test are only available for SPS sections. The modulus of rupture is 

stored in the MODULUS_OF_RUPTURE field. Several other intermediate calculations are also 

included. The primary key consists of the STATE_CODE, SHRP_ID, LAYER_NO, 

89 
FIELD_SET, LOC_NO, TEST_NO, and SAMPLE_NO fields, although STATE_CODE, 

SHRP_ID, and SAMPLE_NO should be sufficient to uniquely identify a specimen. 

13.4.1.7 Test Results for Materials Specific to SPS-3 and -4 

TST_CS01: This table contains data on hot-poured joint sealants for a few SPS-3 and -4 

sections. There are 11 records in this table. For further information on these tests, see the SPS-3 

and -4 data collection guide. 

TST_CS02: This table contains data on silicone joint sealants for a few SPS-3 and -4 sections. 

There are only 12 records in this table. For further information, see the SPS-3 and -4 data 

collection guide. 

TST_SC01: This table contains the results of various tests on asphalt emulsions used in surface 

treatments applied to SPS-3 sections only. Unlike most other tables in the TST module that 

contain the results for a single test, this table contains the results for many tests on the same

material. Most of these tests are straightforward; however, some of them are fairly unusual (in 

these cases, consult the SPS-3 and -4 data collection guide). The primary key consists of the 

STATE_CODE, SHRP_ID, LAYER_NO, FIELD_SET, LOC_NO, and TEST_NO fields, 

although STATE_CODE, SHRP_ID, and SAMPLE_NO should be sufficient to uniquely identify 

a specimen. 

TST_SC02: This table contains the sand equivalency of fine aggregate materials from SPS-3 

sections only. The sand equivalency value, expressed as a percentage, is stored in the 

SAND_EQUIVALENCY field. No intermediate values are stored. The primary key consists of 

the STATE_CODE, SHRP_ID, LAYER_NO, FIELD_SET, LOC_NO, and TEST_NO fields, 

although STATE_CODE, SHRP_ID, and SAMPLE_NO should be sufficient to uniquely identify 

a specimen. 

TST_SC03: This table contains the results of various tests on coarse aggregates used in surface 

treatments applied to SPS-3 sections only. There are three records in this table and no further 

data are expected. For further information, see the SPS-3 and -4 data collection guide. 

TST_SC04: This table contains the flakiness index of aggregates used in surface treatments 

applied to SPS-3 sections only. The flakiness index is stored in the FLAKINESS_INDEX field. 

No intermediate calculations are stored. The primary key consists of the STATE_CODE, 

SHRP_ID, LAYER_NO, FIELD_SET, LOC_NO, and TEST_NO fields, although 

STATE_CODE, SHRP_ID, and SAMPLE_NO should be sufficient to uniquely identify a 

specimen. 

TST_SC05: This table contains the results of various tests on slurry seals applied to SPS-3 

sections only. This table contains a single record and no further data are expected. For further 

information, see the SPS-3 and -4 data collection guide. 

90 
TST_SC06: This table was intended to contain measurements of excess asphalt in bituminous 

mixtures obtained by using a loaded wheel and sand cohesion. Although the table structure 

exists, no data for this test were ever loaded into the database.

TST_SC07: This table contains the results of the wet stripping test of cured slurry seal mixes 

applied to SPS-3 sections only. This table contains a single record and no further data are 

expected. For further information, see the SPS-3 and -4 data collection guide. 

TST_SC08: This table contains the results of the slurry system compatibility test for slurry seals 

applied to SPS-3 sections only. This table contains a single record and no further data are 

expected. For further information, see the SPS-3 and -4 data collection guide. 

TST_SC09: This table contains the results of tests to identify quick-set asphalt emulsions used 

in surface treatments applied to SPS-3 sections only. This table contains a single record and no 

further data are expected. For further information, see the SPS-3 and -4 data collection guide. 

TST_SC10A: This table contains the gradation of aggregates used in chip seals applied to SPS-3 

sections only. Gradation analysis is conducted by sieve test using the 12.5-mm (1⁄2-inch), 9.5-mm

(3⁄8-inch), 4.75-mm (No. 4), 2.36-mm (No.8), 2.00-mm (No. 10), and 75-μm (No. 200) sieves. 

The percent passing each sieve is stored in fields whose name is based on the United States 

(U.S.) customary designation for the sieve size. For example, NO_4_PASSING contains data 

passing the 4.75-mm (No. 4) sieve. The primary key consists of the STATE_CODE, SHRP_ID, 

LAYER_NO, FIELD_SET, LOC_NO, and TEST_NO fields, although STATE_CODE, 

SHRP_ID, and SAMPLE_NO should be sufficient to uniquely identify a specimen. 

TST_SC10B: This table contains the gradation of aggregates used in slurry seals applied to SPS3 sections only. Gradation analysis is conducted by sieve test using the 8.0-mm (5

/16-inch), 4.75-

mm (No. 4), 2.36-mm (No. 8), 1.1.8-mm (No. 16), 600-μm (No. 30), 300-μm (No. 50), 150-μm

(No. 100), and 75-μm (No.200) sieves. The percent passing each sieve is stored in fields whose 

name is based on the U.S. customary designation for the sieve size. For example, the field named 

FIVE_SIXTEENTHS_PASSING contains data for percent retained on the 8.0-mm (5/16-inch) 

sieve. The primary key consists of the STATE_CODE, SHRP_ID, LAYER_NO, FIELD_SET, 

LOC_NO, and TEST_NO fields, although STATE_CODE, SHRP_ID, and SAMPLE_NO 

should be sufficient to uniquely identify a specimen. 

TST_SC11: This table contains various data used in chip seal mix designs applied to SPS-3 

sections only. Factors such as the average least dimension of the aggregate (stored in 

AVG_LEAST_DIMENSION) and the rate of asphalt application (stored in

RESIDUAL_ASPH_SPREAD_RATE) are included. The primary key consists of the 

STATE_CODE, SHRP_ID, LAYER_NO, FIELD_SET, LOC_NO, and TEST_NO fields, 

although STATE_CODE, SHRP_ID, and SAMPLE_NO should be sufficient to uniquely identify 

a specimen. 

TST_SC12: This table contains the asphalt content of slurry seals applied to SPS-3 sections 

only. The percent asphalt by weight of dry aggregate is stored in the ASPHALT_CONTENT 

field. No intermediate results are available. The primary key consists of the STATE_CODE, 

91 
SHRP_ID, LAYER_NO, FIELD_SET, LOC_NO, and TEST_NO fields, although 

STATE_CODE, SHRP_ID, and SAMPLE_NO should be sufficient to uniquely identify a 

specimen. 

TST_SC13: This table was intended to contain measurements of the polish value of aggregates 

used in chip seals applied to SPS-3 sections only. Although the table structure exists, no data for 

this test were ever loaded into the database. 

13.4.1.8 Treated Base Test Results 

TST_TB01: This table contains various classification results for treated base materials. The 

overall description of the treated material is available from the DETAIL_TREAT_MATL field. 

The DETAIL_TREAT_TYPE field identifies the treatment agent. Both fields contain codes of 

the type TREAT_TYPE. There are also two fields (PRELIM_TREAT_MATL and 

PRELIM_TREAT_TYPE) that may have had significance at the beginning of the LTPP 

program; however, they no longer provide useful information except in cases where there is no 

data in the corresponding DETAIL* fields, in which case they may be used as a substitute. There 

are various soil geology-related fields and aggregate-type fields that may or may not be 

populated based on the nature of the treated material. The primary key consists of the 

STATE_CODE, SHRP_ID, LAYER_NO, FIELD_SET, LOC_NO, and TEST_NO fields, 

although STATE_CODE, SHRP_ID, and SAMPLE_NO should be sufficient to uniquely identify 

a specimen. 

TST_TB02: This table contains unconfined compressive strength results for treated base 

materials. Compressive strength (in pounds force per square inch (lbf/inch2

)) is stored in the 

COMP_STRENGTH field. Fracture mode (a code of the type FRACTURE) is stored in the 

COMP_STRENGTH_FRAC field. The primary key consists of the STATE_CODE, SHRP_ID, 

LAYER_NO, FIELD_SET, LOC_NO, and TEST_NO fields, although STATE_CODE, 

SHRP_ID, and SAMPLE_NO should be sufficient to uniquely identify a specimen. 

13.4.1.9 Unbound Materials Testing Results 

TST_SS01_UG01_UG02: This table contains the gradation of unbound coarse-grained granular 

base, subbase, and subgrade materials. Gradation analysis is conducted by the washed sieve test, 

with the washed fines included with the percent passing the 75-μm (No. 200) seive. The sieve set 

specified in the test protocol consists of the 75-mm (3-inch), 50-mm (2-inch), 37.5-mm (11⁄2-

inch), 25.0-mm (1-inch), 19.0-mm (3⁄4-inch), 12.5-mm (1⁄2-inch), 9.5-mm (3⁄8-inch), 4.75-mm (No.

4), 2.00-mm (No. 10), 425-μm (No. 40), 180-μm (No. 80), and 75-μm (No. 200) sieves. The 

name of field is based on the U.S. customary sieve size name. For example, 

ONE_AND_HALF_PASSING contains data for amount of material passing the 37.5-mm (11⁄2-

inch) sieve. In addition, the total dry weight of the sample before washing is stored in the 

SAMPLE_WT field and the moisture content of the sample prior to testing is stored in the 

MOISTURE_CONTENT field. If data are unavailable for a given material, check 

TST_SS02_UG03. The primary key consists of the STATE_CODE, SHRP_ID, LAYER_NO, 

FIELD_SET, LOC_NO, and TEST_NO fields, although STATE_CODE, SHRP_ID, and 

SAMPLE_NO should be sufficient to uniquely identify a specimen. 

92 
TST_SS02_UG03: This table contains the gradation of unbound fine-grained granular base, 

subbase, and subgrade materials. Gradation analysis is conducted by sieve test combined with 

hydrometer analysis. The sieve set used is identical to that used in TST_SS01_UG01_UG02, as 

are the associated field names. In addition, the hydrometer results are expressed as percent size 

smaller (passing) 0.02 mm (780 microinch), 0.002 mm (78 microinch), and 0.001 mm (39 

microinch). These data are stored in fields whose name is based on the SI measurement 

convention. For example HYDRO_02 contains data passing, or smaller than, 0.02 mm (780 

microinch). These values are also expressed as percent gravel (GT_2MM), coarse sand, fine 

sand, silt, clay, and colloids in fields of the same name. If data are unavailable for a given 

material, check the TST_SS01_UG01_UG02 table. The primary key consists of the 

STATE_CODE, SHRP_ID, LAYER_NO, FIELD_SET, LOC_NO, and TEST_NO fields, 

although STATE_CODE, SHRP_ID, and SAMPLE_NO should be sufficient to uniquely identify 

a specimen. 

TST_SS04_UG08: This table contains the general classification of unbound granular base, 

subbase, and subgrade materials. Information in this table includes maximum particle size 

(MAX_PART_SIZE); soil color (SOIL_COLOR); 10 fields for the description codes of the type 

SOIL_CRITERA, including American Society for Testing and Materials (ASTM) classification 

(DESC_CODE_*); and AASHTO classification (AASHTO_SOIL_CLASS). The primary key 

consists of the STATE_CODE, SHRP_ID, LAYER_NO, FIELD_SET, LOC_NO, TEST_NO, 

and SAMPLE_NO fields, although STATE_CODE, SHRP_ID, and SAMPLE_NO should be 

sufficient to uniquely identify a specimen. 

TST_SS06: This table contains the modulus of the subgrade reaction (k-value) of unbound 

subgrade layers. This subgrade reaction is measured by static plate loading. Raw modulus (in 

lbf/inch2

/inch) is stored in SOIL_MOD_UNCORRECTED, while the modulus as corrected for 

plate bending is stored in SOIL_MOD_CORRECTED. The primary key consists of the 

STATE_CODE, SHRP_ID, LAYER_NO, FIELD_SET, and LOC_NO fields. 

TST_SS08: This table contains subgrade in situ moisture and density measurements. These 

measurements are taken on thin-wall tube or split-spoon specimens. Moisture content is stored in 

the MOISTURE_CONTENT field and dry density is stored in the DRY_DENSITY field. A few 

intermediate calculations are also available. The primary key consists of the STATE_CODE, 

SHRP_ID, LAYER_NO, FIELD_SET, LOC_NO, TEST_NO, and SAMPLE_NO fields, 

although STATE_CODE, SHRP_ID, and SAMPLE_NO should be sufficient to uniquely identify 

a specimen. 

TST_SS10: This table contains unconfined compressive strength measurements on subgrade 

materials. Test specimens are obtained by thin-wall tube sampling. Unconfined compressive 

strength is stored in the UNCONFINED_COMPRESSED_STRENGTH field. In addition, the 

moisture content and dry density of the specimen are stored in the MOISTURE_CONTENT and

DRY_DENSITY fields, respectively. The primary key consists of the STATE_CODE, 

SHRP_ID, LAYER_NO, FIELD_SET, LOC_NO, TEST_NO, and SAMPLE_NO fields, 

although STATE_CODE, SHRP_ID, and SAMPLE_NO should be sufficient to uniquely identify 

a specimen. 

93 
TST_SS11: This table contains hydraulic conductivity measurements on subgrade materials 

obtained using a flexible-wall permeameter. Data are only available for a limited number of 

SPS-1, -2, -8, and -9 sections. Test specimens are either thin-wall tube samples or laboratory 

remolds. Hydraulic conductivity is stored in the AVG_HYDRAULIC_CONDUCTIVITY field. 

Several intermediate calculations are also available. The primary key consists of the 

STATE_CODE, SHRP_ID, LAYER_NO, FIELD_SET, LOC_NO, TEST_NO, and 

SAMPLE_NO fields, although STATE_CODE, SHRP_ID, and SAMPLE_NO should be 

sufficient to uniquely identify a specimen. 

TST_SS12: This table contains potential vertical rise (PVR) values for subgrade materials. 

These data are intended for use in identifying expansive soils. This total is the summation of the 

PVR for the first 6.1 m (20 ft) of subgrade depth, tested at 0.61-m (2-ft) intervals. Only three 

records are available in the database. 

TST_UG04_SS03: This table contains the Atterberg limit test results for unbound granular base, 

subbase, and subgrade materials. The liquid limit, plastic limit, and plasticity index are stored in 

the LIQUID_LIMIT, PLASTIC_LIMIT, and PLASTICITY_INDEX fields, respectively. The 

primary key consists of the STATE_CODE, SHRP_ID, LAYER_NO, FIELD_SET, LOC_NO, 

TEST_NO, and SAMPLE_NO fields, although STATE_CODE, SHRP_ID, and SAMPLE_NO 

should be sufficient to uniquely identify a specimen. 

TST_UG05_SS05: This table contains standard Proctor test results for unbound granular base, 

subbase, and subgrade materials. Only the optimum dry density and moisture content are stored 

in the table (in the MAX_LAB_DRY_DENSITY and MAX_LAB_MOISTURE fields, 

respectively). The other points on the moisture-density curve are not loaded into the database. 

The primary key consists of the STATE_CODE, SHRP_ID, LAYER_NO, FIELD_SET, 

LOC_NO, TEST_NO, and SAMPLE_NO fields, although STATE_CODE, SHRP_ID, and 

SAMPLE_NO should be sufficient to uniquely identify a specimen. 

TST_UG09: This table contains the permeability of unbound base and subbase materials as 

tested under constant head using a rigid-wall permeameter. Measured hydraulic conductivity is 

stored in the AVG_HYDRAULIC_CONDUCTIVITY field. Some intermediate calculations are 

also included. The primary key consists of the STATE_CODE, SHRP_ID, LAYER_NO, 

FIELD_SET, LOC_NO, and TEST_NO fields, although STATE_CODE, SHRP_ID, and 

SAMPLE_NO should be sufficient to uniquely identify a specimen. 

TST_UG10_SS09: This table contains the in situ moisture content of unbound base, subbase, 

and subgrade materials as measured by drying samples in the laboratory. Measured moisture 

content is stored in the MOIST_CONTENT field. No intermediate calculations are stored. The 

primary key consists of the STATE_CODE, SHRP_ID, LAYER_NO, FIELD_SET, LOC_NO, 

TEST_NO, and SAMPLE_NO fields, although STATE_CODE, SHRP_ID, and SAMPLE_NO 

should be sufficient to uniquely identify a specimen. 

94 
13.4.1.10 TST_UG07_SS07_* 

The TST_UG07_SS07 family of tables contains resilient modulus data for unbound granular 

base, subbase, and subgrade materials. Testing is conducted according to LTPP Protocol P46. 

Analysts are encouraged to review the test protocol before using the data. The relational structure 

and some test details related to this submodule are illustrated in figure 10. 

TST_UG07_SS07_A: As shown in figure 10, this table contains basic information on the tested

specimen. The information on specimens molded in the laboratory from bulk material includes 

initial length (INITIAL_LENGTH), initial area (INITIAL_AREA), moisture content after testing 

(AFTER_MOIST_CONT), dry density (DRY_DENSITY), and the strength of the specimen as 

measured in the quick shear test (STRENGTH). This table also contains additional information 

used in determining the moisture-density target, including the in situ moisture and density 

(IN_SITU_MOIST and IN_SITU_DENSITY, respectively), and the maximum Proctor density 

and the associated optimum moisture content (MAX_DRY_DENSITY and 

OPT_MOIST_CONT, respectively). The primary key consists of the STATE_CODE, SHRP_ID, 

LAYER_NO, FIELD_SET, LOC_NO, TEST_NO, and SAMPLE_NO fields, although 

STATE_CODE, SHRP_ID, and SAMPLE_NO can be used to uniquely identify a specimen. 

TST_UG07_SS07_B: As shown in figure 10, this table also contains basic information on the 

specimen being tested. The table contains similar information to the TST_UG07_SS07_A table; 

however, it is for undisturbed thin-wall tube specimens only. As in the previous table, the 

information stored includes the initial length (INITIAL_LENGTH), initial area

(INITIAL_AREA), moisture content after testing (AFTER_MOIST_CONT), dry density 

(COMP_DRY_DENSITY), and the strength of the specimen as measured in the quick shear test 

(STRENGTH). The primary key consists of the STATE_CODE, SHRP_ID, LAYER_NO, 

FIELD_SET, LOC_NO, TEST_NO, and SAMPLE_NO fields, although STATE_CODE, 

SHRP_ID, and SAMPLE_NO should be sufficient to uniquely identify a specimen. 

TST_UG07_SS07_WKSHT_CYCLES: This table contains the resilient modulus, loading 

conditions, and intermediate calculations for each load sequence. Data for both remolded and 

thin-wall tube specimens are stored in this table. The loading condition stress states are a 

combination of the confining pressure (stored in the CON_PRESSURE field) and the nominal 

maximum applied axial stress (stored in the MON_MAX_AXIAL_STRESS field). The test 

protocol typically requires 3 levels of confining pressure and 5 levels of nominal maximum 

applied axial stress for a total of 15 unique stress states. (For type 1 materials, only 13 stress 

states are used; the highest two axial stress states for the highest confining pressure are not used.) 

For each stress state, 5 loading sequences of 100 cycles are applied to the specimen. Thus, 75 

records are created in this table for the typical 15 stress states. Applied cyclic stress is stored in 

APPLIED_CYCLIC_STRESS, corrected resilient deformation is stored in CORR_VERT_DEF, 

resilient strain is stored in RES_STRAIN, and resilient modulus is stored in RES_MOD. The 

primary key consists of the STATE_CODE, SHRP_ID, LAYER_NO, FIELD_SET, LOC_NO, 

TEST_NO, SAMPLE_NO, CON_PRESSURE, NOM_MAX_AXIAL_STRESS, and 

CYCLE_NO fields, although STATE_CODE, SHRP_ID, SAMPLE_NO, CON_PRESSURE, 

NOM_MAX_AXIAL_STRESS, and CYCLE_NO should be sufficient to uniquely identify a 

specimen. 

95 
( 1 record per specimen)

TST_UG07_SS07_A

Specimen information for laboratory 

remolded specimens

TST_UG07_SS07_B

Specimen information for thin-walled

tube field specimens

Typical Testing Parameters

3 levels of confining pressure

5 levels of axial load per confining pressure

5 loading cycles per axial load / confining pressure

TST_UG07_WKSHT_CYCLES

Resilient modulus and intermediate

calculations for each combination of

confining pressure, axial load, and

load cycle

( 75 records per specimen)

TST_UG07_SS07_WKSHT_SUM

Average resilient modulus and

intermediate calculations for each

combination of confining pressure

and axial load

( 15 records per specimen)

( 1 record per specimen)

TST_UG07_SS07_A

Specimen information for laboratory 

remolded specimens

TST_UG07_SS07_B

Specimen information for thin-walled

tube field specimens

Typical Testing Parameters

3 levels of confining pressure

5 levels of axial load per confining pressure

5 loading cycles per axial load / confining pressure

TST_UG07_WKSHT_CYCLES

Resilient modulus and intermediate

calculations for each combination of

confining pressure, axial load, and

load cycle

( 75 records per specimen)

TST_UG07_SS07_WKSHT_SUM

Average resilient modulus and

intermediate calculations for each

combination of confining pressure

and axial load

( 15 records per specimen)

Figure 10. Illustration of relationships among TST_UG07_SS07* tables.

96 
TST_UG07_SS07_WKSHT_SUM: This table contains the average resilient modulus and some

intermediate calculations for the five loading sequences at each stress state. Data for both 

remolded and thin-wall tube specimens are stored in this table. The stress state is indicated by the 

combination of the CON_PRESSURE and NOM_MAX_AXIAL_STRESS fields. Average 

cyclic stress and resilient strain are stored in the APPLIED_CYCLIC_STRESS_AVG and 

RES_STRAIN_AVG fields, respectively, with standard deviations stored in

APPLIED_CYCLIC_STRESS_STD and RES_STRAIN_STD. The average and standard 

deviations of the resilient moduli values calculated for that specimen and the stress state are 

stored in the RES_MOD_AVG and RES_MOD_STD fields, respectively. Several intermediate

calculations (including maximum axial stress, contact stress, and average deformations) are also 

included. The primary key consists of the STATE_CODE, SHRP_ID, LAYER_NO, 

FIELD_SET, LOC_NO, TEST_NO, SAMPLE_NO, CON_PRESSURE, and 

NOM_MAX_AXIAL_STRESS fields, although STATE_CODE, SHRP_ID, SAMPLE_NO, 

CON_PRESSURE, and NOM_MAX_AXIAL_STRESS should be sufficient to uniquely identify 

a specimen. 

13.4.2 Sampling Information Tables 

Most of the test results tables contain very little sampling information. Field sampling 

information is stored in the TST_HOLE_LOG and TST_SAMPLE_LOG tables. 

TST_HOLE_LOG: This table contains a record of each core hole, bore hole, or test pit cut in an 

LTPP section for the purpose of extracting material samples. This record includes the date the 

hole was dug; the location of the hole; the dimensions of the hole; and, in some cases, other 

information such as depth to refusal. 

 

LTPP Database 

Tip!

For all samples extracted from an in-service pavement, the date of sampling is 

located in the TST_HOLE_LOG table. The date the sample was tested, where 

available, is located in the same table as the test results. 

The data in the TST_HOLE_LOG table can be linked to data in the various test results tables by 

use of the STATE_CODE, SHRP_ID, and LOC_NO fields. The STATE_CODE and SHRP_ID 

fields together uniquely identify a test section, as described elsewhere in this document. Within a 

given test section, the LOC_NO field uniquely identifies a hole. 

In addition to being useful for linking to TST_HOLE_LOG, the value of LOC_NO contains 

additional information about the hole. The format is as follows: 

L ###t

where: 

L Location type: 

A: 152-mm- (6-inch-) diameter core and/or auger locations 

AD: distributor or slurry seal applicator 

B: bulk sample location

 

97 
BA: 305-mm- (12-inch-) diameter core and bulk base and subgrade 

 sample 

C: 102-mm- (4-inch-) diameter core locations 

CS: 102-mm- (4-inch-) diameter core samples shipped to Materials 

Reference Library for storage 

PB: plate-bearing test location 

S/SP: shoulder augur probe 6 m (19-ft) below the pavement surface 

SO: source of material production 

T/TP: test pit 

TR: delivery truck 

### Location number: Up to a three-digit location number is assigned 

sequentially to each location type on each test section. An asterisk (*) is 

used to identify cases where samples from the same layer were combined 

to satisfy minimum testing requirements. 

For core sample locations taken at specified time intervals from the start of construction on 

SPS-9 projects, a letter is appended to the end of the SAMPLE_NO. It is not used for other 

sample locations. The letter is used to designate the approximate time from paving to coring as 

follows: 

 

 t Time: 

 A: 0 months 

 B: 6 months 

 C: 12 months 

 D: 18 months 

E: 24 months 

F: 48 months 

On some SPS-9 projects, a three-character code is appended to the LOC_NO. This code starts 

with an A and is followed by the last two numbers in the SHRP_ID field. 

Examples of valid sample location numbers include: 

 B01 Bulk sample 01 from a test section 

 A04 Augur location 04 

 C04B Core location 4 from the sampling time interval B, 6 months after paving 

TST_SAMPLE_LOG: While TST_HOLE_LOG contains data for each test hole cut into an 

LTPP section, often multiple samples are extracted from a given test hole. Additional sampling 

information can be found in TST_SAMPLE_LOG. This information includes the depth from

which the sample was taken and a description of the material sampled. 

Records in TST_SAMPLE_LOG can be linked to records in the various test results tables using 

the STATE_CODE, SHRP_ID, and SAMPLE_NO fields. While STATE_CODE and SHRP_ID 

98 
uniquely identify a test section, SAMPLE_NO uniquely identifies samples retrieved within that 

test section.

 

As with LOC_NO, SAMPLE_NO contains useful information and permits linking between 

various TST tables. SAMPLE_NO is typically a four- to six-character value with the following 

format: 

S M ### 

where: 

S Sample type: 

B: bulk sample 

C: core sample

D: gyratory-compacted AC specimen 

F: formed beams with PCC surface 

G: formed cylinders with PCC surface 

H: SPS-3 and -4 oddities 

J: split-spoon sample 

K: block sample 

L: formed cylinders of lean concrete base 

M: moisture sample 

P: broken pieces or chunks of material 

 T: thin-wall tube 

M Material type: 

A: asphalt concrete 

C: asphalt cement 

G: untreated, unbound granular base/subbase 

P: portland cement concrete 

S: subgrade soil or fill material 

T: treated, bound, or stabilized base/subbase 

U: combined aggregate used in concrete mixes 

X: PCC 14-day test specimen 

Y: PCC 28-day test specimen 

Z: PCC 365-day test specimen 

### Sample number: Up to a three-digit sample number assigned sequentially 

to each sample with the same sample and material type designation. An 

asterisk (*) is used to identify cases where samples from the same layer 

were combined to satisfy minimum testing requirements. 

99 
For core sample locations taken at specified time intervals from the start of construction on 

SPS-9 projects, a letter is appended to the end of the SAMPLE_NO. It is not used for other 

sample locations. The letter is used to designate the approximate time from paving to coring as 

follows: 

 A: 0 months 

 B: 6 months 

 C: 12 months 

 D: 18 months 

E: 24 months 

F: 48 months 

On some SPS-9 projects, a three-character code is appended to the SAMPLE_NO. This code 

starts with a time interval letter as noted above and is followed by the last two numbers in the 

SHRP_ID field. 

On SPS-3 and -4 projects, the following material type prefixes are used in the SAMPLE_NO 

code convention: 

HA: aggregate samples 

HC: joint and crack sealing material

HE: emulsified asphalt cement 

The following are examples of valid sample code numbers: 

BA01 Bulk samples of uncompacted HMA 

 BG01 Bulk samples from granular base 

 BS01 Bulk samples of subgrade material 

 CA01D HMA core sample from an SPS-9 project taken during time interval D 

(18 months after construction) 

 CA24A AC cores obtained from SPS-9 projects at time interval A, immediately 

 following paving 

CT24 Treated base cores 

DA01 HMA specimen compacted in SHRP gyratory compactor 

MS01 Subgrade moisture content sample obtained from bulk sampling location 

13.4.2.1 Other Sampling Information Tables 

The TST_HOLE_LOG and TST_SAMPLE_LOG tables contain information for all samples of 

in-place materials. This includes virtually all sampling conducted on GPS test sections. 

However, many SPS sections and GPS overlay sections also include bulk samples of materials 

obtained during construction prior to placement on the roadway. Sampling information for these 

materials is located in one of a series of additional tables (based on material type). 

TST_ASPHALT_CEMENT: This table contains sampling information for bulk samples of 

asphalt cement obtained from the plant. Each asphalt sample has a LOC_NO and a 

100 
SAMPLE_NO that are unique to the section. The table also includes additional information 

about the plant itself. 

TST_FRESH_PCC: This table contains information about test cylinders and beams cast on site 

from concrete used in construction. Each batch of concrete sampled has a unique LOC_NO. Up 

to six cylinders and three beams were cast from each batch of sampled material. Each cylinder 

and beam has a unique SAMPLE_NO. In addition, this table contains information about the 

slump and air content of the sampled concrete. 

TST_SAMPLE_LOG_LAB: This table contains information about specimens molded in the 

laboratory from bulk AC samples. This table is unusual in that it has an “input” sample 

identification (SAMPLE_NO) that identifies the bulk material used and an “output” sample 

number (SAMPLE_NO_LAB) that identifies the compacted specimen that will be used in further 

testing. 

TST_SAMPLE_LOG_SPS_3_4: This table contains sampling information for chip seal, slurry 

seal, or joint sealant material obtained in the field for SPS-3 and -4 sections only. Treatment of 

LOC_NO and SAMPLE_NO are similar to TST_SAMPLE_LOG. 

TST_UNCOMP_BITUMINOUS: This table contains sampling information for uncompacted 

AC specimens obtained during construction. LOC_NO and SAMPLE_NO are unique for a given 

test section. In addition to the time and location the sample was taken, this table also contains 

information on the plant where the asphalt concrete was mixed. 

13.4.3 Layer Tables 

The TST module is the primary source for layer information in the LTPP database. There are two 

tables containing layer thickness information: TST_L05A and TST_L05B. In general, 

TST_L05A can be thought of as the source for measured layer thickness data and TST_L05B 

can be thought of as the source for representative layer thickness. This representative layer 

thickness is based on data stored in TST_L05A in addition to the deflection testing results, 

inventory data, and engineering judgment. LTPP test sections are selected, in part, based on their 

expected homogeneity. As with any real-world pavement structure, variations in material type 

and thickness exist within a test section. Within-section thickness measurements on some layers 

exist for some SPS test sections where rod-and-level measurements were taken during the 

construction event or by ground-penetrating radar. 

LTPP Database 

Tip!

Select the appropriate layer thickness data source based on analytical needs. 

For most analyses, data in TST_L05B is sufficient. 

TST_L05A: This table contains multiple-layer thickness information. Each record in TST_L05A 

is uniquely identified by the STATE_CODE and SHRP_ID of the section, the 

CONSTRUCTION_NO that identifies the period of time for which the structural information is 

valid (for more information on CONSTRUCTION_NO, see the description in section 3.1), and 

the LAYER_NO that identifies the discrete material layers in the pavement section. Each record 

101 
also includes a DESCRIPTION, which identifies the function of the layer in the pavement 

system, and a LAYER_TYPE indicating the general composition of the layer. 

For each record in TST_L05A, there are three sets of fields containing measured thickness, the 

method by which the thickness was determined, and a detailed description of the material 

comprising the layer. These sets correspond to measurements taken at the approach end of the 

section (LAYER_THICK_STATION0, MATERIAL_CODE_STATION0, and 

MEASURE_TYPE_*_STATION0), within the section (LAYER_THICK_WITHIN, 

MATERIAL_CODE_WITHIN, and MEASURE_TYPE_*_WITHIN), and the leave end of the 

section (LAYER_THICK_STATION5, MATERIAL_CODE_STATION5, and 

MEASURE_TYPE_*_STATION5).

For an LTPP section, a LAYER_NO of “1” is always assigned to the lowest identifiable layer in

the pavement section, with progressively higher LAYER_NO’s assigned to the higher layers. 

Although this may seem counterintuitive, it allows the same layer numbering scheme to be 

maintained as new layers are added to the surface of a section because of maintenance or 

rehabilitation treatments. For example, if a section has an uppermost layer with a LAYER_NO = 

5 and that section receives an overlay, the new surface layer will now have a LAYER_NO = 6; 

however, the lower layers will still be referenced to the same LAYER_NO’s. 

Sometimes a layer will be entirely removed by milling; however, it will still be referenced by the 

same LAYER_NO, but the thickness will now be 0. Again, while this may be counterintuitive, it 

maintains the referential integrity of the TST module. For the example above, if the surface layer 

is milled and replaced, LAYER_NO = 5 will have a thickness of 0 and a new LAYER_NO = 6 

will be added to the database for the next CONSTRUCTION_NO. Therefore, materials tests 

keyed to a specific LAYER_NO will represent the same layer in the pavement structure 

regardless of the CONSTRUCTION_NO. 

TST_L05B: This table contains representative thickness information based on multiple data 

sources and engineering judgment, as opposed to the measured layer thickness data stored in 

TST_L05A. Since TST_L05B is of critical importance to the database as a whole, it is more fully 

described in section 13.4.4. 

Like TST_L05A, each record in TST_L05B is uniquely identified by STATE_CODE, 

SHRP_ID, CONSTRUCTION_NO, and LAYER_NO. The representative thickness of the layer 

is stored in the REPR_THICKNESS field and the overall material type is stored in the 

MATL_CODE field. In addition, there are three fields that contain comment codes on how the 

representative thickness was arrived at (LAYER_COMMENT_*) and an additional field for text 

comments (COMMENT_NOTE). 

TST_L05B has an additional field (PROJECT_LAYER_NO) that is useful for linking data 

elements between sections at an SPS project. Its use is further described in section 13.3.4. 

102 
13.4.3.1 Other Layer Tables 

TST_L05: This table contains information that is useful for linking project layers at SPS projects 

to layers in the various SPS INV tables. In practice, it does not contain any information that 

cannot also be obtained from TST_L05B. 

TST_L06: This table contains the sample disposal record for AC specimens. It is of little interest 

to the analyst. 

TST_L07: This table contains the sample disposal record for PCC specimens. It is of little 

interest to the analyst. 

13.4.3.2 Linking Between TST Layer Tables and INV or SPS* Layer Tables 

Although the TST layer tables are the canonical source for layer thickness and description 

information, there may be circumstances in which the analyst will want to compare agencysupplied information located in the INV or SPS* layer tables. This comparison is complicated by 

the fact that site-specific information obtained from the site does not always agree with the 

general information on pavement structure available from agency records. For example, the 

agency may have combined several similar asphalt layers into a single layer, while the LTPP 

program treats them separately. The reverse is also possible. Therefore, the analyst cannot be 

certain that a specific LAYER_NO in the TST module and the same LAYER_NO in the INV or 

SPS modules refer to the same layer. 

To link the TST layer tables and the INV layer table, the INV_LAYER_NO field and/or the 

INV_LAYER_NO2 field in the TST_L05B table must be used. For each record in TST_L05B, 

the INV_LAYER_NO field represents the LAYER_NO used in the INV_LAYER table to

represent that layer. In some cases where a single layer in TST_L05B is treated as two separate 

layers in INV_LAYER, both INV_LAYER_NO and INV_LAYER_NO2 will contain separate 

values to reflect this. In addition, two or more layers in TST_L05B from the same LTPP section 

can share the same INV_LAYER_NO if they are treated as a single layer in INV_LAYER. 

LTPP Database 

Tip!

Some basic materials characterization information is available in the INV

module, SPS*, and the RHB and MNT modules as appropriate to the section 

type. Since this information is not collected under the auspices of the LTPP 

program, its reliability is unknown. However, it may be of value in cases 

where such data are not available in the TST module. 

13.4.4 SPS Complications 

Relating materials testing data back to the layers that they represent is fairly straightforward for 

GPS sections. Generally, all that is needed is the STATE_CODE and SHRP_ID of the section, 

and the LAYER_NO of the layer within that section. Relating such data for SPS sections, 

however, can be more complicated.

103 
An understanding of some of the fundamental differences between the SPS and GPS sections is 

necessary for understanding why SPS materials testing data are more complicated to access. GPS 

test sections are stand-alone in that each section was sampled as a discrete entity. SPS sections, 

however, are clustered with several adjacent sections comprising a project. One of the 

advantages of such clustering is that these sections can share data (e.g., traffic, climate, and 

materials testing data). However, this clustering comes at the price of a slightly more 

complicated data structure. 

To illustrate these complexities, consider a hypothetical SPS project with two sections (1 and 2). 

Figure 11 shows a plan view of this project. Figure 12 shows the cross-sectional view of this 

hypothetical project and the layer numbering. 

Figure 11. Plan view of hypothetical SPS project (not to scale). 

5+00 

CL 

Section 1 

Traffic

Direction

0+00 12+00 17+00

Section 2 

Project 

Layer

No.

Project 

Layer

No.

Layer 

No. 

Project

Layer

No.

Project 

Layer

No.

Layer 

No. Section 01 Section 02 

1 

2 

3 

4 

A

B

D

F Asphalt (AC) 

 Asphalt (AC) 

 Treated Base (TB) 

1 

2 

3 

4 

Subgrade (SS) A 

C 

E 

F 

Subgrade (SS) 

 Granular Base (GB) 

 Asphalt (AC) 

 Asphalt (AC) 

Figure 12. Cross-sectional view of hypothetical SPS project. 

104 
As described in section 13.4.3, the layering of an LTPP section can be obtained from the 

TST_L05B table. From figure 12, we can see that the structures of the two sections are similar, 

except that section 01 has a granular base, while section 02 has a treated base. In both cases, four 

layers have been identified. Thus, in both cases, they have been numbered 1 through 4 (despite 

the fact that layer 2 is different in composition for each section). 

In addition to the section layer numbers (these are sections at an SPS project), TST_L05B also 

contains project layer numbers for these sections. Project layer numbers identify layers

consisting of materials from the same source placed at the same time with the same methods. 

Since the project layer numbers for the surface asphalt layer and the subgrade at these two 

sections are identical, we now know that these layers are continuous and we expect that they 

should have very similar properties. 

LTPP Database 

Tip!

When seeking materials test results for an SPS section, project layer numbers 

can be used to find tests of the same material on a different test section. 

Although the material source and placement methods may be identical, 

construction variability may result in differences in material properties. 

Now that we know that layer F for these two sections is virtually identical (barring construction 

variability stemming from the fact that they are 366 m (1200 ft) apart), we can cross-reference 

materials testing data between these sections. For example, if an analyst wishes to calculate the 

air void content of layer 4 on section 02, the analyst would first have to find the bulk specific 

gravity and theoretical maximum specific gravity of that material in the LTPP database.

However, if only bulk specific gravity results are available for that layer, the analyst could use a 

theoretical maximum specific gravity result for layer 4 at section 01, since there is good reason 

to expect that the material properties are similar. 

13.5 KEY TABLES 

13.5.1 TST_L05B

The TST_L05B table can be considered the master table for the entire TST module. It is the best 

source for pavement layer thickness information. The layer thickness values stored in this table 

are those that the regional data collection contractors recommend as being the best representative 

values based on the inspection of field sampling information, deflection measurements, and 

laboratory measurements on cores. Therefore, each of the data elements included in this table is 

discussed below. 

 

SHRP_ID is a four-character identifier for the test section. It must be combined with 

STATE_CODE to be unique for a test section. 

STATE_CODE uses the STATE_PROVINCE code in the CODES table to define the owning 

agency and geographical location of the test section. Note that STATE_PROVINCE codes exist 

for many nations that are not currently participants in the LTPP program. 

105 
CONSTRUCTION_NO identifies changes in the pavement structure caused by rehabilitation 

treatments or application of maintenance treatments. When a section first enters the LTPP 

program, it is assigned a CONSTRUCTION_NO of 1. The CONSTRUCTION_NO is

incremented by 1 for each subsequent maintenance or rehabilitation event regardless of its 

impact on the pavement structure. For example, crack sealing could cause a new construction 

event to be generated even though it does not cause a change in the experiment assignment or 

pavement structure. This table and EXPERIMENT_SECTION are the only tables in which 

CONSTRUCTION_NO is manually entered. In all other tables in the database, 

CONSTRUCTION_NO is computed based on the date of the event. 

 

LAYER_NO is a unique identifier for the layers in the pavement system. A LAYER_NO of 1 is 

always assigned to the lowest layer in the pavement system, with each identifiable layer above it 

getting a progressively larger LAYER_NO. 

PROJECT_LAYER_NO is an SPS project-level layer identifier. Use of this field can allow 

layers in different sections on the same SPS project with the same material properties to be 

identified. 

DESCRIPTION is a code of the type DESCRIPTION that describes the function of the layer in 

the pavement structure. Common DESCRIPTION codes are 03 for the original pavement 

surface, 01 for an overlay, and 07 for a subgrade. 

LAYER_TYPE is a code of the type LAYER_TYPE that provides a basic description of the 

composition of the layer. Common LAYER_TYPES are “SS” for subgrade, “GS” for granular 

subbase, “GB” for granular base, “AC” for asphaltic concrete, and “PC” for portland cement 

concrete. 

REPR_THICKNESS is the representative thickness of the pavement layer. It is a best estimate 

of a single representative value of layer thickness based on several data sources, including cores, 

analysis of deflection data, and elevation surveys.

MATL_CODE is a code of the type MATERIAL that describes the material composition of the 

layer. It is much more specific than the general LAYER_TYPE classification. 

LAYER_COMMENT_1 (_2, _3) are comments of the type L05B_COMMENT_CODES that 

describe how the representative layer thickness was determined. 

COMMENT_NOTE contains additional comments (if any) about the layer. 

INV_LAYER_NO is a link to the agency-supplied layer information in the INV module. This is 

necessary because the agency-provided data and site-specific measurements taken by the LTPP 

program do not always agree on the detailed layering structure at the test section location. For 

example, the presence of embankments at the test section site is often not included in the agency 

data. 

106 
INV_LAYER_NO_2 is used in circumstances where a single layer as described in TST_L05B is 

described as two separate layers in the INV module. 

107 
CHAPTER 14. OBTAINING LTPP DATA 

14.1 DATA RELEASE POLICY 

The following principles apply for release of LTPP data and information: 

• LTPP data and information are distributed under the sponsorship of the U.S. Department 

of Transportation in the interest of information exchange. The U.S. Government assumes 

no liability for its contents or use. 

• Understanding LTPP data collection procedures, principles, and practices is the 

responsibility of data users who interpret and draw conclusions based on LTPP data and 

information. 

• While the LTPP program strives to provide data and information at no cost to the data 

user, program-funding limitations may limit the level of effort spent on user requests. 

• Extractions from the LTPP database are provided free of charge to data users who request 

data in standard data release formats. 

• Custom extractions from the database may be requested. 

• Delivery of data in raw data collection formats, access to internal documents, and access 

to other LTPP offline information will be assessed on a case-by-case basis. 

• Some LTPP publications are available for free download from the LTPP Internet Web 

site. 

14.2 OBTAINING LTPP DATA 

All requests for LTPP data and information should be made to the LTPP customer service center. 

LTPP customer service can be contacted via e-mail at ltppinfo@fhwa.dot.gov. Other contact 

information is posted on the LTPP Internet Web page at www.tfhrc.gov/pavement/ltpp/ltpp.htm. 

LTPP data can be obtained through a variety of mechanisms, including standard data release, 

custom data extraction, and via the DataPave computer program and the Internet. 

14.2.1 Standard Data Release 

The most up-to-date data from the LTPP program are distributed in January and July in the 

standard data release format. These data are available free of charge to data requesters. No data 

restrictions are placed on the content of the data provided in the tables included in the release. 

The released tables include all data at all levels of RECORD_STATUS. 

The standard data release is currently formatted as a series of Microsoft Access 2000 databases 

based on the North American software version. In the standard release, the pavement 

108 
performance database is divided into multiple databases by data module. FWD and profile data 

modules are subdivided by highway agency to meet Microsoft Access database size limitations. 

The standard data release is currently formatted on five CD-ROMs. The first volume contains the 

majority of the data modules, while the other compact discs contain the subdivided FWD and 

profile data sets. 

Use of the standard data release requires knowledge of relational database concepts, the 

relational design of the LTPP database, and features of the Microsoft Access software. Users of 

the standard release have the flexibility of performing both simple and complex joins between 

data elements stored in related data tables to create analysis data sets for many types of pavement 

performance analyses. Appendix C provides examples of how to extract and create an analysis 

database that can be conveniently queried by exporting tables from the distribution database 

files. 

The structure of the standard data release format also allows users not familiar with the relational 

database concept to look at the data in separate tables from a spreadsheet viewpoint. Each table 

is formatted in columns and rows just like an electronic spreadsheet. This self-discovery feature 

facilitates progression of use of the expanded data manipulation functions offered by database 

software that is not available in some spreadsheet types of computational software. 

LTPP Database 

Tip!

Because of the volume of LTPP data, LTPP database users should use modern 

database tools to examine, manipulate, and extract data. Some tables contain 

more than 1,000,000 records. LTPP customer service can provide limited 

technical assistance to database users on the use of these tools.

14.2.2 Custom Extractions 

Data users can request partial extractions from the database and/or extractions in a nonstandard 

format. The support and availability of custom data extractions will be evaluated on a case-bycase basis. While users are encouraged to use the standard data release format, database 

extractions can be conveniently provided in ASCII, comma-delimited ASCII, or Microsoft Excel 

2000 formats. Users interested in obtaining data in other formats must contact the LTPP 

customer service center. 

14.2.3 DataPave 

The LTPP DataPave program provides a static release of data from a majority of tables in a userinteractive format. The current version of the program is stored on two CD-ROMs and includes 

only data whose RECORD_STATUS equals E]. 

DataPave was designed as a training tool for users of LTPP data who are not acquainted with the 

use of modern database technology. Since it currently contains program modules based on a 

static data release, it is not possible to provide data updates to the program without a new release. 

The most current LTPP data can be obtained from the LTPP standard data release, which is 

updated every 6 months. 

109 
14.2.4 LTPP Data Over the Internet 

Plans are underway to make LTPP data available for download over the Internet. Check the 

LTPP Web page at www.tfhrc.gov/pavement/ltpp/ltpp.htm for information on data availability 

over the Internet. 

110 

APPENDIX A. LTPP OPERATIONS REFERENCE DOCUMENTS 

A.1 GENERAL 

America’s Highways, Accelerating the Search for Innovation, Special Report 202, TRB, 

National Research Council, June 1984. 

Data Collection Guide for Long-Term Pavement Performance Studies, FHWA, Pavement 

Performance Division, LTPP Division, revised October 1993. 

Fulfilling the Promise of Better Roads, A Report of the TRB Long-Term Pavement 

Performance Committee, TRB, 2001. 

An Investment Benefiting America’s Highways, The Long-Term Pavement Performance 

Program, FHWA, Pavement Performance Division, 2001. 

LTPP Product Plan, Publication No. FHWA-RD-01-086, FHWA, Pavement Performance 

Division, 2001. 

SHRP-LTPP Overview: Five-Year Report, Publication No. SHRP-P-416, SHRP, National 

Research Council, June 1994. 

Strategic Highway Research Program, Research Plans, Final Report, TRB, National Research 

Council, National Cooperative Highway Research Program (NCHRP), May 1986. 

Strategic Highway Research Program, Saving Lives, Reducing Congestion, Improving Quality 

of Life, Special Report 260, TRB, National Research Council, 2001. 

A.2 PAVEMENT MONITORING 

Analysis of Pavement Homogeneity, Non-Representative Test Pit and Section Data, and 

Structural Capacity, FWDCHECK, Version 2.0, Volume I: Technical Report, Volume 2: 

Users Guide, Publication Nos. SHRP-P-633 and SHRP-P-634, SHRP, National Research 

Council, January 1991. 

Calibration of Reference Load Cell, Software User’s Guide and Instruction Manual, 

LDCELCAL, Version 1.7, FHWA, Pavement Performance Division, June 1993. 

Distress Identification Manual for the Long-Term Pavement Performance Studies,

Operational Guide No. SHRP-LTPP-OG-001, SHRP, National Research Council, 1993. 

Falling Weight Deflectometer, Relative Calibration Analysis, FWDCAL, Version 2.00, 

Program Manual, SHRP, National Research Council, April 1992. 

Falling Weight Deflectometer, Relative Calibration Analysis, RELCAL, Version 3.00, 

Program Manual, SHRP, National Research Council, May 1994. 

112 
Guidelines for Users of the SHRP FWD Calibration Centers, Publication No. FHWA-SA-95-

038, FHWA, Pavement Performance Division, November 1994. 

Long-Term Pavement Performance PROQUAL User’s Documentation, Version 2.08, FHWA, 

June 1998. 

LTPP Manual for Profile Measurements, Operational Field Guidelines, Version 3.1, FHWA, 

Pavement Performance Division, January 1999. 

LTPP Manual for Falling Weight Deflectometer Measurements, Operational Field 

Guidelines, Version 2.0, FHWA, Pavement Performance Division, LTPP Division, February 

1993.

LTPP Manual for Falling Weight Deflectometer Measurements, Operational Field 

Guidelines, Version 3.0, FHWA, Pavement Performance Division, LTPP Division, January 

2000.

LTPP Manual for Falling Weight Deflectometer Measurements, Operational Field 

Guidelines, Version 3.1, FHWA, Pavement Performance Division, LTPP Division, August 

2000. 

Manual for Profile Measurement: Operational Field Guidelines, Publication No. SHRP-P-378, 

SHRP, National Research Council, February 1994.

PROQUAL, Version 1.4, User Documentation, FHWA, Pavement Performance Division, June 

1992. 

Reference Calibration of Falling-Weight Deflectometers, Software User’s Guide and 

Instruction Manual, FWDREFCAL, Version 3.72, SHRP, National Research Council, March 

1994. 

SHRP/LTPP FWD Calibration Protocol, FHWA, Pavement Performance Division, March 

1994. 

Study of LTPP Distress Data Variability, Volumes I and II, Report Nos. FHWA-RD-99-074 

and FHWA-RD-99-075, FHWA, Pavement Performance Division, September 1999. 

A.3 MATERIALS SAMPLING AND TESTING 

SHRP-LTPP Guide for Field Materials Sampling, Handling, and Testing, Operational Guide 

No. SHRP-LTPP-OG-006, SHRP, National Research Council, February 1991. 

SHRP-LTPP Interim Guide for Laboratory Materials Handling and Testing, Operational 

Guide No. SHRP-LTPP-OG-004, SHRP, National Research Council, November 1989, revised 

July 1997. 

113 
A.4 SEASONAL MONITORING PROGRAM 

CR10 Data Logger Software and CR10 Procedure Manager, Version 4.01, FHWA, 

Pavement Performance Division, January 1997. 

LTPP Seasonal Monitoring Program: Instrumentation Installation and Data Collection 

Guidelines, Publication No. FHWA-RD-94-110, FHWA, Pavement Performance Division, April 

1994. 

LTPP Seasonal Monitoring Program: MOBFIELD Users Guide, Version 2.4, FHWA, 

Pavement Performance Division, January 1997. 

LTPP Seasonal Monitoring Program: MOBFIELD Users Guide, Version 3.0, FHWA, 

Pavement Performance Division, December 1999. 

LTPP Seasonal Monitoring Program: ONSFIELD Users Guide, Version 1.2, FHWA, 

Pavement Performance Division, June 1996. 

LTPP Seasonal Monitoring Program: ONSFIELD Users Guide, Version 2.0, FHWA, 

Pavement Performance Division, December 1999. 

LTPP Seasonal Monitoring Program: SMPCheck Users Guide, Version 2.5, FHWA, 

Pavement Performance Division, October 1996. 

LTPP Seasonal Monitoring Program: SMPCheck Users Guide, Version 5.0, FHWA, 

Pavement Performance Division, January 2000. 

A.5 GPS EXPERIMENTS 

Recruitment Guidelines for Additional GPS Candidate Projects, SHRP, National Research 

Council, October 1988. 

A.6 SPS EXPERIMENTS 

Specific Pavement Studies, Experimental Design and Participation Requirements, Operational 

Memorandum No. SHRP-LTPP-OM-005R, SHRP, National Research Council, July 1990. 

Specific Pavement Studies, Pavement Layering Methodology, FHWA, Pavement Performance 

Division, January 1994. 

Specific Pavement Studies, Construction Guidelines for Experiment SPS-1, Strategic Study of 

Structural Factors for Flexible Pavements, Operational Memorandum No. SHRP-LTPP-OM017, SHRP, National Research Council, December 1990, revised FHWA, December 1993. 

114 
Specific Pavement Studies, Data Collection Guidelines for Experiment SPS-1, Strategic Study 

of Structural Factors for Flexible Pavements, Operational Memorandum No. SHRP-LTPPOM-026, SHRP, National Research Council, December 1991. 

Specific Pavement Studies, Experimental Design and Research Plan for Experiment SPS-1, 

Strategic Study of Structural Factors for Flexible Pavements, SHRP, National Research 

Council, revised February 1990. 

Specific Pavement Studies, Guidelines for Nomination and Evaluation of Candidate Projects 

for Experiment SPS-1, Strategic Study of Structural Factors for Flexible Pavements, 

Operational Memorandum No. SHRP-LTPP-OM-008, SHRP, National Research Council, 

February 1990. 

Specific Pavement Studies, Materials Sampling and Testing Requirements for Experiment 

SPS-1, Strategic Study of Structural Factors for Flexible Pavements, FHWA, Pavement 

Performance Division, revised January 1994. 

Specific Pavement Studies, Construction Guidelines for Experiment SPS-2, Strategic Study of 

Structural Factors for Rigid Pavements, Operational Memorandum No. SHRP-LTPP-OM-018, 

SHRP, National Research Council, 1991. 

Specific Pavement Studies, Data Collection Guidelines for Experiment SPS-2, Strategic Study 

of Structural Factors for Rigid Pavements, Operational Memorandum No. SHRP-LTPP-OM028, SHRP, National Research Council, February 1992. 

Specific Pavement Studies, Experimental Design and Research Plan for Experiment SPS-2, 

Strategic Study of Structural Factors for Rigid Pavements, SHRP, National Research Council, 

April 1990. 

Specific Pavement Studies, Guidelines for Nomination and Evaluation of Candidate Projects 

for Experiment SPS-2, Strategic Study of Structural Factors for Rigid Pavements, Operational 

Memorandum No. SHRP-LTPP-OM-009, SHRP, National Research Council, April 1990. 

Specific Pavement Studies, Materials Sampling and Testing Requirements for Experiment 

SPS-2, Strategic Study of Structural Factors for Rigid Pavements, FHWA, Pavement 

Performance Division, revised June 1994. 

Specific Pavement Studies, Data Collection Guidelines for Experiment SPS-3, Maintenance 

Effectiveness for Asphalt Concrete Pavements, SHRP, National Research Council, June 1990. 

Specific Pavement Studies, Data Collection Guidelines for Experiment SPS-4, Maintenance 

Effectiveness for Portland Cement Concrete Pavements, SHRP, National Research Council, 

November 1991. 

115 
Specific Pavement Studies, Construction Guidelines for Experiment SPS-5, Rehabilitation of 

Asphalt Concrete Pavements, Operational Memorandum No. SHRP-LTPP-OM-012, SHRP, 

National Research Council, June 1990. 

Specific Pavement Studies, Data Collection Guidelines for Experiment SPS-5, Rehabilitation 

of Asphalt Concrete Pavements, Operational Memorandum No. SHRP-LTPP-OM-015, SHRP, 

National Research Council, October 1990. 

Specific Pavement Studies, Experimental Design and Research Plan for Experiment SPS-5,

Rehabilitation of Asphalt Concrete Pavements, SHRP, National Research Council, April 1989. 

Specific Pavement Studies, Guidelines for Nomination and Evaluation of Candidate Projects 

for Experiment SPS-5, Rehabilitation of Asphalt Concrete Pavements, Operational 

Memorandum No. SHRP-LTPP-OM-006, SHRP, National Research Council, November 1989.

Specific Pavement Studies, Materials Sampling and Testing Requirements for Experiment 

SPS-5, Rehabilitation of Asphalt Concrete Pavements, Operational Memorandum No. SHRPLTPP-OM-014, SHRP, National Research Council, October 1990. 

Specific Pavement Studies, Construction Guidelines for Experiment SPS-6, Rehabilitation of 

Jointed Portland Cement Concrete Pavements, Operational Memorandum No. SHRP-LTPPOM-013, SHRP, National Research Council, July 1990. 

Specific Pavement Studies, Data Collection Guidelines for Experiment SPS-6, Rehabilitation 

of Jointed Portland Cement Concrete Pavements, Operational Memorandum No. SHRP-LTPPOM-023, SHRP, National Research Council, May 1991. 

Specific Pavement Studies, Experimental Design and Research Plan for Experiment SPS-6,

Rehabilitation of Jointed Portland Cement Concrete Pavements, SHRP, National Research 

Council, November 1989. 

Specific Pavement Studies, Guidelines for Nomination and Evaluation of Candidate Projects 

for Experiment SPS-6, Rehabilitation of Jointed Portland Cement Concrete Pavements, 

Operational Memorandum No. SHRP-LTPP-OM-007, SHRP, National Research Council, 

November 1989. 

Specific Pavement Studies, Materials Sampling and Testing Requirements for Experiment 

SPS-6, Rehabilitation of Jointed Portland Cement Concrete Pavements, Operational 

Memorandum No. SHRP-LTPP-OM-019, SHRP, National Research Council, January 1991. 

Specific Pavement Studies, Construction Guidelines for Experiment SPS-7, Bonded Portland 

Cement Concrete Overlays, Operational Memorandum No. SHRP-LTPP-OM-016, SHRP, 

National Research Council, December 1990. 

116 
Specific Pavement Studies, Data Collection Guidelines for Experiment SPS-7, Bonded 

Portland Cement Concrete Overlays, Operational Memorandum No. SHRP-LTPP-OM-024, 

SHRP, National Research Council, July 1991. 

Specific Pavement Studies, Experimental Design and Research Plan for Experiment SPS-7, 

Bonded Portland Cement Concrete Overlays, SHRP, National Research Council, February 

1990. 

Specific Pavement Studies, Guidelines for Nomination and Evaluation of Candidate Projects 

for Experiment SPS-7, Bonded Portland Cement Concrete Overlays, Operational 

Memorandum No. SHRP-LTPP-OM-011, SHRP, National Research Council, June 1990. 

Specific Pavement Studies, Materials Sampling and Testing Requirements for Experiment 

SPS-7, Bonded Portland Cement Concrete Overlays, Operational Memorandum No. SHRPLTPP-OM-020, SHRP, National Research Council, January 1991. 

Specific Pavement Studies, Construction Guidelines for Experiment SPS-8, Study of 

Environmental Effects in the Absence of Heavy Loads, Operational Memorandum No. SHRPLTPP-OM-029, SHRP, National Research Council, March 1992. 

Specific Pavement Studies, Data Collection Guidelines for Experiment SPS-8, Study of 

Environmental Effects in the Absence of Heavy Loads, Operational Memorandum No. SHRPLTPP-OM-031, SHRP, National Research Council, September 1992. 

Specific Pavement Studies, Experimental Design and Research Plan for Experiment SPS-8, 

Study of Environmental Effects in the Absence of Heavy Loads, SHRP, National Research 

Council, August 1991. 

Specific Pavement Studies, Materials Sampling and Testing Requirements for Experiment 

SPS-8, Study of Environmental Effects in the Absence of Heavy Loads, Operational 

Memorandum No. SHRP-LTPP-OM-030, SHRP, National Research Council, August 1992. 

Specific Pavement Studies, Materials Sampling and Testing Requirements for Experiment 

SPS-8, Study of Environmental Effects in the Absence of Heavy Loads, FHWA, Pavement 

Performance Division, revised October 1997. 

Specific Pavement Studies, Experimental Design and Research Plan for Experiment SPS-9, 

Validation of SHRP Asphalt Specifications and Mix Design and Innovations in Asphalt 

Pavements, SHRP, National Research Council, February 1992. 

Specific Pavement Studies, Guidelines for Nomination and Evaluation of Candidate Projects 

for Experiment SPS-9, Validation of SHRP Asphalt Specifications and Mix Design and 

Innovations in Asphalt Pavements, SHRP, National Research Council, February 1992. 

Specific Pavement Studies, Construction Guidelines for Experiment SPS-9A, Superpave 

Asphalt Binder Study, FHWA, Pavement Performance Division, September 1995. 

117 
Specific Pavement Studies, Experimental Design and Research Plan for Experiment SPS-9A, 

Superpave Asphalt Binder Study, FHWA, Pavement Performance Division, January 1995. 

 

Specific Pavement Studies, Guidelines for Nomination and Evaluation of Candidate Projects 

for Experiment SPS-9A, Superpave Asphalt Binder Study, FHWA, Pavement Performance 

Division, August 1994. 

Specific Pavement Studies, Materials Sampling and Testing Requirements for Experiment 

SPS-9A, Superpave Asphalt Binder Study, FHWA, Pavement Performance Division, February 

1996. 

A.7 TRAFFIC DATA 

Flexible Pavement Load Equivalency Factors (LEF) Based on Structural Number Estimates 

Using the SHRP-LTPP IMS Inventory Data, Tech Memo No. AU-167, November 1990. 

Guide to LTPP Traffic Data Collection and Processing, FHWA, Pavement Performance 

Division, March 2001.

Load Equivalency Factors (LEF) Estimates for GPS-LTPP Rigid Pavements Based on SHRPLTPP IMS Inventory Data, Tech Memo No. AU-168, November 1990.

Long-Term Pavement Performance Program Protocol for Calibrating Traffic Data Collection 

Equipment, FHWA, Pavement Performance Division, April 1998. 

LTPP Traffic Database Librarian Software, Version 4.0, FHWA, Pavement Performance 

Division, April 1997. 

LTPP Traffic QC Software, Technical Documentation, FHWA, Pavement Performance 

Division, 1997. 

LTPP Traffic Software Technical Documentation, FHWA, Pavement Performance Division, 

July 1997. 

LTPP Traffic Software Users Guide, FHWA, Pavement Performance Division, June 1997. 

Managing Purge Documents Using Purge Operations Software, FHWA, Pavement 

Performance Division, February 1998. 

Revised Data Collection Plan for LTPP Sites, FHWA, Pavement Performance Division, April 

1998. 

Running the Level 4 Traffic Quality Control Filter Program, FHWA, Pavement Performance 

Division, June 1997. 

118 
Traffic Analysis Software, Volume 1: User’s Guide, FHWA, Office of Infrastructure Research, 

Development, and Technology, August 2002. 

Users Manual for Level 3 Through 1LTPP Traffic Quality Control Software, FHWA, 

Pavement Performance Division, July 1997. 

A.8 CLIMATIC DATA 

Climate Data Collection Plan for SPS Test Sites, FHWA, Pavement Performance Division, 

January 1993, revised May 1993. 

LTPP Climatic Database Revision and Expansion, Draft Report, FHWA, Pavement 

Performance Division, July 1999. 

LTPP-SPS Automated Weather Stations: Automated Weather Station (AWS) Installation, 

Arizona DOT Open House, Phoenix, AZ, July 20-21, 1994. 

LTPP-SPS Automated Weather Stations: AWSCheck Users Guide, Version 1.1, FHWA, 

Pavement Performance Division, November 1996. 

LTPP-SPS Automated Weather Stations: AWSScan Program Background and Users Guide, 

Version 1.11, FHWA, Pavement Performance Division, February 1996. 

A.9 DYNAMIC LOAD RESPONSE DATA 

Development of an Instrumentation Plan for the Ohio SPS Test Pavement, Final Report, 

Publication No. DEL-23-17.48, Ohio DOT and FHWA, October 1994. 

SPS-2 Seasonal and Load Response Instrumentation, North Carolina DOT Open House, 

Lexington, NC, FHWA, Pavement Performance Division, May 9-11, 1994. 

A.10 SITE REPORTS 

A.10.1 SPS Materials Sampling, Field Testing, and Laboratory Testing Plans 

The SPS materials sampling, field testing, and laboratory testing plans are very valuable sources 

of information for data users who want to interpret the materials data collected at SPS sites. 

Unlike the GPS materials sampling and testing plans, which are relatively uniform from site to 

site, the sampling plans for SPS sites vary substantially between sites since they are tailored to 

site conditions, construction sequence, test section sequence, etc. For example, to compute 

certain material properties, the test results from samples obtained at different test sections must 

be combined. 

119 
A.10.1.1 North Atlantic Region 

Updated Materials Sampling and Testing Plans for SPS-1 Project, US 113, SBL, Delaware, 

FHWA, Pavement Performance Division, March 1995. 

SPS-1 Materials Sampling and Testing Plans, Project 510100, Rt. 265, SB, Danville, Virginia, 

FHWA, Pavement Performance Division, November 1994. 

Revision to SPS-1 and SPS-2 Construction and Materials and Testing Guidelines, Delaware, 

FHWA, Pavement Performance Division, April 1994. 

Report of Site Investigation on Delaware SPS-2 Problem Test Sections, FHWA, Pavement 

Performance Division, August 1995. 

Revised Materials Sampling and Testing Plans SPS-2, US 113, SBL, Delaware, FHWA, 

Pavement Performance Division, August 1994. 

Revised Materials Sampling and Testing Plans, SPS-2, US 52 SB, Lexington, By-Pass, North 

Carolina, FHWA, Pavement Performance Division, February 1995. 

SPS-5 Materials Sampling and Testing Plans, Project 230500, I-95 NB, Argyle, Maine, 

FHWA, Pavement Performance Division, July 1994. 

SPS-5 Materials Sampling and Testing Plans, Project 240500, US-15 NB, Frederick, 

Maryland, FHWA, Pavement Performance Division, January 1992. 

SPS-5 Materials Sampling and Testing Plans, Project 340500, I-195 WB, Imlaystown, New 

Jersey, FHWA, Pavement Performance Division, September 1994. 

SPS-6 Materials Sampling and Testing Plans, Project 420600, I-80 WB, Centre County, 

Pennsylvania, FHWA, Pavement Performance Division, July 1994. 

SPS-8 Materials Sampling and Testing Plans, Project 340800, Port Authority of NY/NJ, JFK 

Airport, FHWA, Pavement Performance Division, September 1994. 

SPS-8 Materials Sampling and Testing Plans, Project 360800, Lake Ontario State Parkway, 

Brockport, New York, FHWA, Pavement Performance Division, February 1994. 

SPS-8 Materials Sampling and Testing Plans, Project 370800, SR 1245, Jacksonville, North 

Carolina, FHWA, Pavement Performance Division, revised August and October 1997. 

SPS-9 Pilot, Materials Sampling and Testing Plans, Project 240900, I-70 WB, Frederick, 

Maryland, Memo, July and September 1992. 

SPS-9A Materials Sampling and Testing Plan Revisions, Connecticut, FHWA, Pavement 

Performance Division, December 1997. 

120 
Revised SPS-9A Materials Sampling and Testing Plans, Project 340900, I-195 EB, Allentown, 

New Jersey, FHWA, Pavement Performance Division, December 1997, revised May 1998.

SPS-9A Materials Sampling and Testing Plans, Project 370900, NB/SB, Sanford, North 

Carolina, FHWA, Pavement Performance Division, revised February and June 1997. 

SPS-9A Materials Sampling and Testing Plans, Project 870900, Hwy. 17 WB, Petawawa, 

Ontario, FHWA, Pavement Performance Division, revised May 1997. 

SPS-9A Materials Sampling and Testing Plans, Projects 890900, NR 170 WB, and 89A900, 

NR 170 EB, Jonquiere, Quebec, FHWA, Pavement Performance Division, revised February 

1997. 

A.10.1.2 North Central Region 

As-Sampled, Sampling and Testing Plan, SPS-1 Experimental Project, US-27 Southbound, 

Clinton County, Michigan, FHWA, Pavement Performance Division, March 1995. 

Sampling and Testing Plan, SPS-1 Experimental Project, US-27 Southbound, Clinton County, 

Michigan, FHWA, Pavement Performance Division, February 1994. 

Sampling and Testing Plan, SPS-1 Experimental Project, STH 29, Marathon County, 

Wisconsin, FHWA, Pavement Performance Division, updated July 1997. 

Mix Designs and Summary of Concrete Test Results, SPS-2 I-70 Westbound, Kansas, FHWA, 

Pavement Performance Division, April 1993. 

Summary of Test Run at the Kansas SPS-2 Project in 1992, FHWA, Pavement Performance 

Division, April 1993. 

As-Sampled Sampling and Testing Plan, SPS-2 Experimental Project, US-23 Northbound, 

Monroe County, Michigan, FHWA, Pavement Performance Division, March 1995. 

Sampling and Testing Plan, SPS-2 Experimental Project, Westbound and Eastbound, 

Marathon County, Wisconsin, FHWA, Pavement Performance Division, updated July 1997. 

Sampling, Testing, and Monitoring Activities, SPS-5, Plan for Test Sections Located on 

Highway 1 Westbound Near Brokenhead River, Manitoba, Canada, FHWA, Pavement 

Performance Division, June 1989. 

As-Sampled Sampling and Testing Plan, SPS-8 Experimental Project, Ramp A, Delaware 

County, Ohio, FHWA, Pavement Performance Division, May 1995. 

Sampling and Testing Plan, SPS-8 Experimental Project, Ramp A, Delaware County, Ohio, 

FHWA, Pavement Performance Division, May 1994. 

121 
Draft Sampling and Testing Plan, SPS-8 Experimental Project, Apple Lane, Marathon 

County, Wisconsin, FHWA, Pavement Performance Division, updated July 1997. 

Work Plan, Materials Sampling and Testing, Missouri SPS-9A, FHWA, Pavement 

Performance Division, updated July 1996. 

Sampling and Testing Plan, SPS-9A Experimental Project, US-23 Southbound, Delaware 

County, Ohio, FHWA, Pavement Performance Division, September 1995.

Materials Sampling and Testing Plan, SPS-9A, Highway 16 (Yellowhead Highway), 

Saskatoon, Saskatchewan, FHWA, Pavement Performance Division, May 1996. 

A.10.1.3 Southern Region 

Sampling and Testing Plan for SPS-1 Test Site in Alabama, FHWA, Pavement Performance 

Division, April 1992. 

Materials Sampling and Testing Plan, Arkansas SPS-1 Project 050100, US-63 NBL, 

Craighead County, Arkansas, FHWA, Pavement Performance Division, January 1993. 

Materials Sampling and Testing Plan, Florida SPS-1 Project 120100, US-27 SBL, Palm 

Beach County, Florida, FHWA, Pavement Performance Division, August 1996. 

Laboratory Materials Testing for LTPP SPS-1 Project 2201, US-171, Calcasiu Parish, 

Louisiana, FHWA, Pavement Performance Division, July 1995. 

Louisiana SPS-1 (220100), Revised Materials Sampling and Testing Plan, FHWA, Pavement 

Performance Division, January 1993, revised December 1993.

Materials Sampling and Testing Plan, New Mexico SPS-1 Project 350100, IH-25 NBL, Dona 

Ana County, New Mexico, FHWA, Pavement Performance Division, June 1994. 

Materials Sampling and Testing Plan, Oklahoma SPS-1 Project 400100, US-62 EBL, 

Comanche County, Oklahoma, FHWA, Pavement Performance Division, July 1996. 

Materials Sampling and Testing Plan, Texas SPS-1 Project 480100, US-281 SBL, Hidalgo 

County, Texas, FHWA, Pavement Performance Division, December 1996. 

Arkansas SPS-2 (050200), Materials Sampling and Testing Plan, FHWA, Pavement 

Performance Division, February 1994. 

Materials Sampling and Testing Plan, Arkansas SPS-2 Project 050200, IH-30 WBL, Hot 

Spring County, Arkansas, FHWA, Pavement Performance Division, January 1997.

122 
Materials Sampling and Testing Plan, Alabama SPS-5 Project 010500, US-84 EBL, Houston 

County, Alabama, FHWA, Pavement Performance Division, March 1996. 

Materials Sampling and Testing Plan, Florida SPS-5 Project 120500, US-1 SBL, Martin 

County, Florida, FHWA, Pavement Performance Division, November 1994.

Materials Sampling and Testing Plan, Georgia SPS-5 Project 130500, IH-75 SBL, Bartow 

County, Georgia, FHWA, Pavement Performance Division, April 1993. 

Materials Sampling and Testing Plan, New Mexico SPS-5 Project 350500, IH-10 EBL, Grant

County, New Mexico, FHWA, Pavement Performance Division, September 1995. 

Materials Sampling and Testing Plan, Oklahoma SPS-5 Project 400500, US-62 WBL, 

Comanche County, Oklahoma, FHWA, Pavement Performance Division, July 1996. 

Sampling, Testing, and Monitoring Activities, Specific Pavement Studies–Experiment 5, 

Rehabilitation of Asphaltic Concrete Pavements, Plan for Test Sections, SHRP, National 

Research Council, July 1989. 

Materials Sampling and Field Testing Plan for SPS Section 48A5 in Kaufman, Texas, FHWA, 

Pavement Performance Division, December 1990. 

Alabama SPS-6 Project (010600), Materials Sampling and Field Testing Plan, FHWA, 

Pavement Performance Division, February 1998. 

Materials Sampling and Field Testing Plan, Arkansas SPS-6 Project 05A6, US-65 

Southbound, Jefferson County, Arkansas, FHWA, Pavement Performance Division, June 1997.

Materials Sampling and Field Testing Plan, Oklahoma SPS-6 Project 4006, IH-35 

Southbound, Kay County, Oklahoma, FHWA, Pavement Performance Division, March 1992. 

Materials Sampling and Field Testing Plan, Tennessee SPS-6 Project 4706, IH-40 

Westbound, Madison County, Tennessee, FHWA, Pavement Performance Division, June 1995. 

Materials Sampling and Field Testing Plan, Louisiana SPS-7 Project 2207, IH-10 Eastbound, 

Ascension Parish, Louisiana, FHWA, Pavement Performance Division, May 1991.

Materials Sampling and Testing Plan, Arkansas SPS-8 Project 050800, US-65 East Terminal 

Interchange, Right Frontage Road, Jefferson County, Arkansas, FHWA, Pavement 

Performance Division, October 1996. 

Materials Sampling and Testing Plan, Mississippi SPS-8 Project 280800, SR-315 NBL, 

Panola County, Mississippi, FHWA, Pavement Performance Division, April 1996. 

123 
Materials Sampling and Testing Plan, New Mexico SPS-8 Project 350800, Grant County, New 

Mexico, IH-10 Frontage Road Eastbound, FHWA, Pavement Performance Division, August 

1995. 

Materials Sampling and Testing Plan, Texas SPS-8 Project 480800, FM-2223 EBL, Brazos 

County, Texas, FHWA, Pavement Performance Division, August 1995. 

Materials Sampling and Testing Plan, Texas SPS-8 Project 48A800, FM-2670, Bell County, 

Texas, FHWA, Pavement Performance Division, March 2000. 

Materials Sampling and Testing Plan, Arkansas SPS-9A Project 050900, US-65 Southbound, 

Jefferson County, Arkansas, FHWA, Pavement Performance Division, June 1997. 

Materials Sampling and Testing Plan, Florida SPS-9A Project 120900, Columbia County, 

Florida, IH-10 Eastbound, FHWA, Pavement Performance Division, March 1996. 

Materials Sampling and Testing Plan, Mississippi SPS-9A Project 280900, Panola County, 

Mississippi, IH-55 Southbound, FHWA, Pavement Performance Division, June 1995. 

Materials Sampling and Testing Plan, New Mexico SPS-9A Project 350900, Grant County, 

New Mexico, IH-10 Eastbound, FHWA, Pavement Performance Division, August 1995. 

Materials Sampling and Testing Plan, Texas SPS-9A Project 480900, Bexar County, Texas, 

Loop 1604 Southbound, FHWA, Pavement Performance Division, August 1995. 

A.10.1.4 Western Region 

Materials Sampling, Field Testing, and Laboratory Testing Plan, Strategic Highway Research 

Program, SPS-1 Experimental Project, Federal Aid Project No. F-39-1-509, State Highway 

No. US-93, Mohave County, Arizona, FHWA, Pavement Performance Division, March 1993. 

Materials Sampling, Field Testing, and Laboratory Testing Plan, Strategic Highway Research 

Program, SPS-1 and SPS-2 Experimental Projects, Interstate Highway No. I-80, Humboldt 

and Lander Counties, Nevada, FHWA, Pavement Performance Division, September 1994. 

Addendum to Materials Sampling, Field Testing, and Laboratory Testing Plan, Strategic 

Highway Research Program, SPS-1 and SPS-2 Experimental Projects, Interstate Highway No. 

I-80, Humboldt and Lander Counties, Nevada, FHWA, Pavement Performance Division, April 

1995. 

Materials Sampling, Field Testing, and Laboratory Testing Plan, Strategic Highway Research 

Program, SPS-1 and SPS-9 Experimental Projects, I-15, Cascade County, Montana, FHWA, 

Pavement Performance Division, October 1997. 

Materials Sampling, Field Testing, and Laboratory Testing Plan, Strategic Highway Research 

Program, SPS-2 Experimental Project, Federal Aid Project No. IR-10-2(146), Ehrenberg124 
Phoenix State Highway, Maricopa County, Arizona, FHWA, Pavement Performance Division, 

January 1993. 

Materials Sampling, Field Testing, and Laboratory Testing Plan, Strategic Highway Research 

Program, SPS-2 Experiment Project, Federal Aid Project No. ACNH-P099(370)Y, SR 99 at 

and Near Delhi and Various Locations, Merced County, California, FHWA, Pavement 

Performance Division, February 1999. 

Materials Sampling, Field Testing, and Laboratory Testing Plan, Strategic Highway Research 

Program, SPS-2 Experimental Project, Federal Aid Project No. ACDPS-0027(001), 395–Lind 

to Ritzvile, Washington, FHWA, Pavement Performance Division, March 1993. 

Materials Sampling, Field Testing, and Laboratory Testing Plan, Strategic Highway Research 

Program, SPS-2 and SPS-8 Experimental Projects, Federal Aid Project No. I 076-1(138), 

State Highway No. I-76, Adams County, Colorado, FHWA, Pavement Performance Division, 

May 1992. 

Materials Sampling, Field Testing, and Laboratory Testing Plan, Strategic Highway Research 

Program, SPS-8 Experimental Project (Flexible and Rigid), Federal Aid Project No. ACNHP099(370)Y, Sycamore Street, Delhi, Merced County, California, FHWA, Pavement 

Performance Division, February 1999. 

Materials Sampling, Field Testing, and Laboratory Testing Plan, Strategic Highway Research 

Program, SPS-8 Experimental Project, Federal Aid Project No. RS 273-1(2)0, State Highway 

No. RS 273, Deerlodge County, Montana, FHWA, Pavement Performance Division, April 1994. 

Materials Sampling, Field Testing, and Laboratory Testing Plan, Strategic Highway Research 

Program, SPS-8 Experimental Project, Utah Forest Highway and Federal Lands Highway 

Project 5-2(3), State Highway 35 (Wolf Creek Road), Wasatch County, Utah, FHWA, 

Pavement Performance Division, April 1996. 

Materials Sampling, Field Testing, and Laboratory Testing Plan, Strategic Highway Research 

Program, SPS-8 Experimental Project, Project Nos. PFH 176-1(1) and RS-A070(002), North 

Touchet Road, Columbia County, Washington, FHWA, Pavement Performance Division, June 

1994. 

Materials Sampling, Field Testing, and Laboratory Testing Plan, Strategic Highway Research 

Program, SPS-8 Experimental Project (Rigid), Project No. CRP 93-13, Smith Springs Road, 

Walla Walla County, Washington, FHWA, Pavement Performance Division, September 1999.

A.10.2 SPS Construction Reports 

The SPS construction reports provide data users with site-specific information and notes on the 

general layout of the site, site features, construction problems, nonstandard construction features, 

and other information not easily captured on the data sheets. 

125 
A.10.2.1 North Atlantic Region 

Construction Report on SHRP 100100, SPS-1 Project, Ellendale, Delaware, Publication No. 

FHWA-TS-96-10-01, FHWA, Pavement Performance Division, June 1996. 

Construction Report on LTPP 510100, SPS-1 Project, Danville, Virginia, FHWA, Pavement 

Performance Division, June 1996. 

Construction Report on LTPP 100200, SPS-2 Project, Ellendale, Delaware, Publication No. 

FHWA-TS-96-10-04, FHWA, Pavement Performance Division, October 1996. 

Report of Site Investigation on Delaware SPS-2 Problem Test Sections, FHWA, Pavement 

Performance Division, July 1995. 

Construction Report on LTPP 370200, SPS-2 Project, Lexington, North Carolina, FHWA, 

Pavement Performance Division, August 1994. 

Construction Report on LTPP 24A300, SPS-3 Project, Ocean City, Maryland, FHWA, 

Pavement Performance Division, October 1990. 

Construction Report on LTPP 36A300 and 36B300, SPS-3 Projects, Glen Falls and Cranberry 

Lake, New York, FHWA, Pavement Performance Division, October 1990. 

Construction Report on LTPP 42A300 and 42B300, SPS-3 Projects, Lewisburg and Knoxville,

Pennsylvania, FHWA, Pavement Performance Division, October 1990. 

Construction Report on LTPP 51A300, SPS-3 Project, Petersburg, Virginia, FHWA, Pavement 

Performance Division, 1990. 

Construction Report on LTPP 87A300 and 87B300, SPS-3 Projects, Moonstone and

Bracebridge, Ontario, FHWA, Pavement Performance Division, October 1990. 

Construction Report on LTPP 89A300, SPS-3 Project, Trois-Rivieres, Quebec, FHWA, 

Pavement Performance Division, 1990. 

Construction Report on LTPP 230500, SPS-5 Project, Argyle, Maine, Publication No. FHWATS-95-23-02, FHWA, Pavement Performance Division, December 1995. 

Construction Report on LTPP 240500, SPS-5 Project, Frederick, Maryland, FHWA, Pavement 

Performance Division, March 1993. 

Construction Report on LTPP 340500, SPS-5 Project, Imlaystown, New Jersey, FHWA, 

Pavement Performance Division, December 1994. 

Construction Report on LTPP 420600, SPS-6 Project, Snowshoe, Pennsylvania, FHWA, 

Pavement Performance Division, May 1995. 

126 
Construction Report on LTPP 340800, SPS-8 Project, NY/NJ, JFK Airport, Port Authority, 

Publication No. FHWA-TS-94-34-01, FHWA, Pavement Performance Division, December 

1994. 

Construction Report on LTPP 360800, SPS-8 Project, Lake Ontario State Parkway, 

Brockport, New York, Publication No. FHWA-TS-95-36-01, FHWA, Pavement Performance 

Division, March 1995. 

Construction Report on LTPP 370800, SPS-8 Project, Jacksonville, North Carolina,

Publication No. FHWA-TS-98-37-02, FHWA, Pavement Performance Division, December 

1998. 

Construction Report on LTPP 240900, SPS-9 Project, Frederick, Maryland, FHWA, Pavement 

Performance Division, December 1992. 

Construction Report on LTPP 090900, SPS-9A Project, Colchester, Connecticut, Publication 

No. FHWA-TS-98-09-02, FHWA, Pavement Performance Division, June 1998. 

Construction Report on LTPP 340900, SPS-9A Project, Allentown, New Jersey, Publication 

No. FHWA-TS-00-34-01, FHWA, Pavement Performance Division, December 2000. 

Construction Report on LTPP 370900, SPS-9A Project, NB and SB, Sanford, North Carolina,

Publication No. FHWA-TS-00-37-02, FHWA, Pavement Performance Division, June 2000. 

Construction Report on LTPP 870900, SPS-9A Project, Petawawa, Ontario, Publication No. 

FHWA-TS-98-87-02, FHWA, Pavement Performance Division, March 1998. 

Construction Report on LTPP 890900 and 89A900, SPS-9A Projects, Jonquiere, Quebec,

Publication No. FHWA-TS-98-89-02, FHWA, Pavement Performance Division, April 1998. 

A.10.2.2 North Central Region 

SPS-1 Construction Report, US-54 Near Fort Madison, Iowa, Sections 190101 to 190112, 

FHWA, Pavement Performance Division, April 1994. 

SPS-1 Construction Report, US-54 Near Greensburg, Kansas, Sections 200101 to 200164, 

FHWA, Pavement Performance Division, April 1994. 

SPS-1 Construction Report, U.S. Highway 81 Southbound, 80 Miles Southwest of Lincoln, 

Nebraska, (4 Miles) North of the Kansas Border, Sections 310113 to 310124, FHWA, 

Pavement Performance Division, June 1996. 

SPS-1 Construction Report, U.S. Highway 23 Southbound, Delaware County, Ohio, Sections 

390101 to 390112, 390159, and 390160, FHWA, Pavement Performance Division, September 

1998. 

127 
SPS-1 Construction Report, STH 29 Westbound, Marathon County, Wisconsin, Sections 

550113 to 550124, FHWA, Pavement Performance Division, March 2000. 

SPS-2 Construction Report, US-65 Northbound, Polk County, Iowa, Sections 190213 to 

190224, FHWA, Pavement Performance Division, June 1996. 

SPS-2 Construction Report, I-70 Near Abilene, Kansas, Sections 200201 to 200212, FHWA, 

Pavement Performance Division, March 1993. 

SPS-2 Construction Report, US 23 Northbound, Monroe County, Michigan, FHWA, Pavement

Performance Division, December 1995.

SPS-2 Construction Report, I-94 Eastbound, West of Fargo, North Dakota, Sections 380213 to 

380224, FHWA, Pavement Performance Division, June 1996. 

SPS-2 Construction Report, U.S. Highway 23 Northbound, Delaware County, Ohio, Sections 

390201 to 390212 and 390259 to 390265, FHWA, Pavement Performance Division, September 

1998. 

SPS-2 Construction Report, STH 29 Westbound, Marathon County, Wisconsin, Sections 

550213 to 550224 and 550259 to 550266, FHWA, Pavement Performance Division, December 

1999. 

SPS-5 Construction Report, Trunk Highway 2 Westbound, 14 Miles West of Bemidji, 

Minnesota, Core Sections 270501 to 270509 and Supplemental Sections 270559 to 270561, 

FHWA, Pavement Performance Division, June 1996.

SPS-5 Construction Report, PTH No. 1 Westbound, 35 Miles East of Winnipeg, Manitoba, 

Sections 830501 to 830509, FHWA, Pavement Performance Division, June 1996.

SPS-6 Construction Report, I-35 Southbound, Between Ames and Des Moines, Iowa, Test 

Sections 190601 to 190608, FHWA, Pavement Performance Division, June 1996. 

SPS-6 Construction Report, US-10 Eastbound, Bay County, Michigan, FHWA, Pavement 

Performance Division, December 1995.

SPS-6 Construction Report, US Highway 12 Westbound, Approximately 15 Miles East of 

Aberdeen, South Dakota, Test Sections 460601 to 460608, FHWA, Pavement Performance 

Division, June 1996. 

SPS-7 Construction Report, I-35 Near Ames, Iowa, Sections 190701 to 190710, FHWA, 

Pavement Performance Division, April 1994.

SPS-7 Construction Report, Interstate 94 Eastbound, Between Moorhead and Barnesville, 

Minnesota, Sections 270701 to 270709, FHWA, Pavement Performance Division, June 1996.

128 
Construction Report for SPS-7, Route 67 Northbound, Jefferson County, Missouri, FHWA, 

Pavement Performance Division, December 1995.

Construction Report for SPS-8, Ramp A, Delaware County, Ohio, FHWA, Pavement 

Performance Division, December 1995. 

SPS-8 South Dakota, Construction Report, State Highway 1804, Pollock, South Dakota, 

Sections 460803 and 460804, Supplemental Section 460859, FHWA, Pavement Performance 

Division, June 1996. 

SPS-9 Construction Report, US-54 Near Greensburg, Kansas, Sections 200901 to 200903, 

FHWA, Pavement Performance Division, December 1993. 

SPS-9 Construction Report, US-169, Near Belle Plaine, Minnesota, Sections 270901 to 

270903, FHWA, Pavement Performance Division, April 1995.

SPS-9 Construction Report, I-94 Near Tomah, Wisconsin, Sections 550901 to 550909, FHWA, 

Pavement Performance Division, June 1994. 

SPS-9 Construction Report, I-43 Near Milwaukee, Wisconsin, Sections 55A901 to 55A909 and 

Sections 55B901 to 55B909, FHWA, Pavement Performance Division, June 1994. 

SPS-9A Construction Report, U.S. 65 Southbound, Sedalia, Missouri, Sections 290901 to 

290903 and 290959 to 290964, FHWA, Pavement Performance Division, September 1998. 

SPS-9A Construction Report, U.S. Highway 81 Southbound, 80 Miles Southwest of Lincoln, 

Nebraska, (4 Miles) North of the Kansas Border, Sections 310901 to 310903, FHWA, 

Pavement Performance Division, June 1996. 

 

SPS-9A Construction Report, Yellow Head Highway Westbound, Radisson, Saskatchewan, 

Sections 900901 to 900903 and 900959 to 900962, FHWA, Pavement Performance Division, 

September 1998. 

A.10.2.3 Southern Region 

Southern Region SPS Tour, FHWA, Pavement Performance Division, October 1995. 

SPS-1 Project 0101, Strategic Study of Structural Factors for Flexible Pavements, US-280 

Westbound, Lee County, Alabama, Final Report, FHWA, Pavement Performance Division, 

February 1996. 

SPS-1 Project 0501, Strategic Study of Structural Factors for Flexible Pavements, US-63 

Northbound, Craighead County, Arkansas, Final Report, FHWA, Pavement Performance 

Division, October 1996. 

129 
SPS-1 Project 1201, Strategic Study of Structural Factors for Flexible Pavements, US-27 

Southbound, Palm Beach County, Florida, Final Report, FHWA, Pavement Performance 

Division, December 1996. 

SPS-1 Project 2201, Strategic Study of Structural Factors for Flexible Pavements, US-171 

Northbound, Calcasieu Parish, Louisiana, Final Report, FHWA, Pavement Performance 

Division, May 1998. 

SPS-1 Project 3501, Strategic Study of Structural Factors for Flexible Pavements, IH-25 

Northbound, Dona Ana County, New Mexico, Final Report, FHWA, Pavement Performance 

Division, April 1996. 

SPS-1 Project 4001, Strategic Study of Structural Factors for Flexible Pavements, US-62 

Eastbound, Comanche County, Oklahoma, Final Report, FHWA, Pavement Performance 

Division, August 1998. 

SPS-1 Project 4801, Strategic Study of Structural Factors for Flexible Pavements, US-281 

Southbound, Hidalgo County, Texas, Final Report, FHWA, Pavement Performance Division, 

December 1997. 

SPS-2 Project 0502, Strategic Study of Structural Factors for Rigid Pavements, I-30 

Westbound, Hot Springs County, Arkansas, Final Report, FHWA, Pavement Performance 

Division, November 1997. 

Report on the SPS-3 Experiment of the Long-Term Pavement Performance Project in the 

Southern Region, Publication No. FHWA-IF-00-026, FHWA, Pavement Performance Division, 

August 2000. 

SPS-3 Construction Report, SHRP Southern Region Coordination Office, FHWA, Pavement 

Performance Division, January 1991. 

SPS-4 Construction Report, SHRP Southern Region Coordination Office, FHWA, Pavement 

Performance Division, February 1991. 

SPS-5 Project 0105, Asphalt Rehabilitation Study, US-84 Eastbound, Houston County, 

Alabama, Final Report, FHWA, Pavement Performance Division, March 1996. 

SPS-5 Project 1205, Asphalt Rehabilitation Study, US-1 Southbound, Martin County, Florida, 

Final Report, FHWA, Pavement Performance Division, April 1996. 

SPS-5 Project 1305, Asphalt Rehabilitation Study, IH-75 Southbound, Bartow County, 

Georgia, Final Report, FHWA, Pavement Performance Division, January 1996. 

SPS-5 Project 2805, Asphalt Rehabilitation Study, IH-55 Northbound, Yazoo County, 

Mississippi, Final Report, FHWA, Pavement Performance Division, April 1993. 

130 
SPS-5 Project 3505, Asphalt Rehabilitation Study, IH-10 Eastbound, Grant County, New 

Mexico, Final Report, FHWA, Pavement Performance Division, May 1997. 

SPS-5 Project 4005, Asphalt Rehabilitation Study, US-62 Westbound, Comanche County, 

Oklahoma, Final Report, FHWA, Pavement Performance Division, October 1998. 

SPS-5 Project 4805, Asphalt Rehabilitation Study on US-175 in Kaufman County, Texas, 

Final Report, FHWA, Pavement Performance Division, July 1992. 

SPS-6 Project 0106, Rehabilitation of Jointed Portland Cement Concrete Pavements, I-59 

Southbound, Etowah County, Alabama, Final Report, FHWA, Pavement Performance 

Division, May 1999. 

SPS-6 Project 05A6, Rehabilitation of Jointed Portland Cement Concrete Pavements, US-65 

Southbound, Jefferson County, Arkansas, Final Report, FHWA, Pavement Performance 

Division, October 1997. 

SPS-6 Project 4006, Rehabilitation of Jointed Portland Cement Concrete Pavements, IH-35 

Southbound, Kay County, Oklahoma, Final Report, FHWA, Pavement Performance Division, 

June 1993. 

SPS-6 Project 4706, Rehabilitation of Jointed Portland Cement Concrete Pavements, IH-40 

Westbound, Madison County, Tennessee, Final Report, FHWA, Pavement Performance 

Division, March 1997. 

SPS-7 Project 2207, Bonded Concrete Overlay of a Concrete Pavement, IH-10 Eastbound, 

Ascension Parish, Louisiana, Final Report, FHWA, Pavement Performance Division, April 

1993. 

SPS-8 Project 0508, Environmental Effects in the Absence of Heavy Loads, US-65 East 

Terminal Interchange, Right Frontage Road, Jefferson County, Arkansas, Final Report, 

FHWA, Pavement Performance Division, December 1998. 

SPS-8 Project 2808, Environmental Effects in the Absence of Heavy Loads, SR-315 

Westbound, Panola County, Mississippi, Final Report, FHWA, Pavement Performance 

Division, February 1998. 

SPS-8 Project 3508, Environmental Effects in the Absence of Heavy Loads, IH-10 Frontage 

Road, Grant County, New Mexico, Final Report, FHWA, Pavement Performance Division, 

May 1997. 

SPS-8 Project 4808, Environmental Effects in the Absence of Heavy Loads, FM-2223 

Eastbound, Brazos County, Texas, Final Report, FHWA, Pavement Performance Division, 

October 1996. 

131 
SPS-8 Project 48A8, Environmental Effects in the Absence of Heavy Loads, FM-2670 

Eastbound, Bell County, Texas, Final Report, FHWA, Pavement Performance Division, July 

2000. 

SPS-9A Project 0509, Superpave Asphalt Binder Study, US-65 Southbound, Pulaski County, 

Arkansas, Final Report, FHWA, Pavement Performance Division, September 1997.

SPS-9A Project 1209, Superpave Asphalt Binder Study, IH-10 Eastbound, Columbia County, 

Florida, Final Report, FHWA, Pavement Performance Division, March 1997. 

SPS-9A Project 2809, Superpave Asphalt Binder Study, IH-55 Southbound, Panola County, 

Mississippi, Final Report, FHWA, Pavement Performance Division, November 1996. 

SPS-9A Project 3509, Superpave Asphalt Binder Study, IH-10 Eastbound, Grant County, New 

Mexico, Final Report, FHWA, Pavement Performance Division, May 1997. 

SPS-9A Project 4809, Superpave Asphalt Binder Study, FM-1604 Southbound, Bexar County, 

Texas, Final Report, FHWA, Pavement Performance Division, January 1996. 

A.10.2.4 Western Region 

Construction Report on Site 040200, Interstate Highway No. I-10, Maricopa County, Arizona, 

Final Report, FHWA, Pavement Performance Division, May 1994. 

Construction Report on Site 040500, Interstate Highway No. I-8, Casa Grande, Arizona, Final 

Report, Arizona Transportation Research Center, Arizona DOT, October 1990. 

Construction Report on Site 040600, Interstate Highway No. I-40, Flagstaff, Arizona, Final 

Report, FHWA, Pavement Performance Division, November 1992. 

Construction Report on Site 040900/04A900, U.S. 93, Arizona Department of Transportation, 

Kingman, Arizona, Final Report, FHWA, Pavement Performance Division, December 1997. 

Construction Report on Site 060200, SR 99, Delhi, California, Final Report, FHWA, 

Pavement Performance Division, December 2002. 

Construction Report on Site 060500, Interstate 40, California Department of Transportation, 

Barstow, California, Final Report, FHWA, Pavement Performance Division, April 1996. 

Construction Report on Site 060600, Interstate Highway No. I-5, Mt. Shasta City, California, 

Final Report, FHWA, Pavement Performance Division, April 1996. 

Construction Report on Site 060800, Sycamore Street, Delhi, California, Final Report,

FHWA, Pavement Performance Division, August 2002. 

132 
Construction Report on Site 06A800, Sycamore Street, Delhi, California, Final Report, 

FHWA, Pavement Performance Division, August 2002. 

Construction Report on Site 080500, Interstate 70, Colorado Department of Transportation, 

Lincoln County, Colorado, Final Report, FHWA, Pavement Performance Division, October 

1994. 

Construction Report on Site 080800, Chestnut Street, Colorado Department of Transportation, 

Adams County, Colorado, Draft Report, FHWA, Pavement Performance Division, June 1998. 

Construction Report on Site 300100, Interstate Highway 15, Cascade County, Montana, Final 

Report, FHWA, Pavement Performance Division, November 2002. 

Construction Report on Site 300500, Interstate 90, Big Timber, Montana, Final Report, 

FHWA, Pavement Performance Division, January 1992. 

Construction Report on Site 300900, Interstate Highway 15, Cascade County, Montana, Final 

Report, FHWA, Pavement Performance Division, August 2002. 

Construction Report on Site 320100, Interstate Highway No. I-80, Humboldt and Lander 

Counties, Nevada, Final Report, FHWA, Pavement Performance Division, March 1998. 

Construction Report on Site 320200, Interstate Highway No. I-80, Humboldt and Lander 

Counties, Nevada, Final Report, FHWA, Pavement Performance Division, March 1998. 

Construction Report on Site 300800, SR 273, Adams County, Washington, Final Report, 

FHWA, Pavement Performance Division, August 1996. 

Construction Report on Site 530200, SR 395, Adams County, Washington, Final Report, 

FHWA, Pavement Performance Division, March 1997. 

Construction Report on Site 530800, North Touchet Road, Dayton, Washington, Final Report,

FHWA, Pavement Performance Division, September 1997. 

Construction Report on Site 53A800, Smith Springs Road, Clyde, Washington, Final Report, 

FHWA, Pavement Performance Division, August 2002. 

Construction Report on Site 810500, Highway 16, Alberta Transportation and Utilities 

Department, Edson, Alberta, Final Report, FHWA, Pavement Performance Division, July 1993. 

Construction Report on Site 81A900, Highway 2, Alberta Transportation and Utilities 

Department, Okotoks, Alberta, Draft Report, FHWA, Pavement Performance Division, March 

1997. 

FHWA LTPP Specific Pavement Studies, Arizona SPS-1, Construction Report on SHRP 

040100, Draft Report, FHWA, Pavement Performance Division, April 1995. 

133 
Investigation of Premature Distress in Asphalt Overlays on IH-70 in Colorado, Cooperative 

Applied Research between the Asphalt Institute and Colorado DOT, Denver, Colorado. 

SPS-2 Construction Report, SHRP 080200, Federal Aid Project No. I 076-1 (138), I-76 

Eastbound, Milepost 18.43, Adams County, Colorado, FHWA, Pavement Performance 

Division, September 1998. 

SPS-3 Construction Report, SHRP Western Region, Final Report, SHRP, National Research 

Council, December 1990. 

SPS-8 Construction Report on Site 490800, State Route 35 (Wolf Creek Road), Utah, Draft 

Report, FHWA, Pavement Performance Division, September 1998. 

SPS-9A I-10 Westbound Milepost 112-123, Construction Report on Site 04B900, Arizona, 

Draft Report, FHWA, Pavement Performance Division, August 1998. 

A.10.3 SMP Installation Reports 

The SMP site installation reports provide valuable information to analysts interested in the LTPP 

SMP data. Information contained in these reports includes: sensor installation, sensor check and 

calibration, site layout, problems during installation, nonstandard installation features, 

gravimetric moisture measurements taken during TDR installation, site photographs, and 

pavement layer structure in the instrumentation hole. 

A.10.3.1 North Atlantic Region 

LTPP Seasonal Monitoring Program: Site Installation and Initial Data Collection, Section 

091803, Groton, Connecticut, Publication No. FHWA-TS-95-09-01, FHWA, Pavement 

Performance Division, September 1995. 

LTPP Seasonal Monitoring Program: Site Installation and Initial Data Collection, Section 

100102, Ellendale, Delaware, Publication No. FHWA-TS-96-10-02, FHWA, Pavement 

Performance Division, June 1996. 

LTPP Seasonal Monitoring Program: Site Installation and Initial Data Collection, Section 

231026, East Dixfield, Maine, Publication No. FHWA-TS-94-23-01, FHWA, Pavement 

Performance Division, June 1994. 

LTPP Seasonal Monitoring Program: Site Installation and Initial Data Collection, Section 

241634, Ocean City, Maryland, Publication No. FHWA-TS-96-24-01, FHWA, Pavement 

Performance Division, June 1996. 

LTPP Seasonal Monitoring Program: Site Installation and Initial Data Collection, Section 

251002, Chicopee, Massachusetts, Publication No. FHWA-TS-94-25-01, FHWA, Pavement 

Performance Division, June 1994. 

134 
LTPP Seasonal Monitoring Program: Site Installation and Initial Data Collection, Section 

331001, Concord, New Hampshire, Publication No. FHWA-TS-94-33-01, FHWA, Pavement 

Performance Division, June 1994. 

LTPP Seasonal Monitoring Program: Site Installation and Initial Data Collection, Section 

360801 Hamlin, New York, Publication No. FHWA-TS-96-36-01, FHWA, Pavement 

Performance Division, June 1996. 

LTPP Seasonal Monitoring Program: Site Installation and Initial Data Collection, Section 

364018, Oneonta, New York, Publication No. FHWA-TS-95-36-01, FHWA, Pavement 

Performance Division, September 1995. 

LTPP Seasonal Monitoring Program: Site Installation and Initial Data Collection, Sections 

370201, 370205, 370208, and 370212, Lexington, North Carolina, Publication No. FHWA-TS97-37-01, FHWA, Pavement Performance Division, March 1997. 

LTPP Seasonal Monitoring Program: Site Installation and Initial Data Collection, Section 

371028, Elizabeth City, North Carolina, Publication No. FHWA-TS-96-37-01, FHWA, 

Pavement Performance Division, June 1996. 

LTPP Seasonal Monitoring Program: Site Installation and Initial Data Collection, Section 

421606, Altoona, Pennsylvania, Publication No. FHWA-TS-96-42-01, FHWA, Pavement 

Performance Division, June 1996. 

LTPP Seasonal Monitoring Program: Site Installation and Initial Data Collection, Section 

501002, New Haven, Vermont, Publication No. FHWA-TS-94-50-01, FHWA, Pavement 

Performance Division, December 1994. 

LTPP Seasonal Monitoring Program: Site Installation and Initial Data Collection, Section 

510113, Danville, Virginia, Publication No. FHWA-TS-96-51-03, FHWA, Pavement 

Performance Division, June 1996. 

LTPP Seasonal Monitoring Program: Site Installation and Initial Data Collection, Section 

510114, Danville, Virginia, Publication No. FHWA-TS-96-51-02, FHWA, Pavement 

Performance Division, June 1996. 

LTPP Seasonal Monitoring Program: Site Installation and Initial Data Collection, Section 

871622, Bracebridge, Ontario, Publication No. FHWA-TS-94-87-01, FHWA, Pavement 

Performance Division, December 1994. 

LTPP Seasonal Monitoring Program: Site Installation and Initial Data Collection, Section 

893015, Trois-Rivieres, Quebec, Publication No. FHWA-TS-94-89-01, FHWA, Pavement 

Performance Division, June 1996. 

135 
Seasonal Testing Instrumentation Pilot, GPS 361011, 1H 481 SB, E. Syracuse, New York, 

SHRP, National Research Council, October 1991. 

A.10.3.2 North Central Region 

LTPP Seasonal Monitoring Program, Site Installation Report for GPS Section 183002 (18A), 

Lafayette, Indiana, FHWA, Pavement Performance Division, February 1996. 

LTPP Seasonal Monitoring Program, Site Installation Report for GPS Section 204054 (20A), 

Enterprise, Kansas, FHWA, Pavement Performance Division, February 1996. 

LTPP Seasonal Monitoring Program, Site Installation Report for GPS Section 271018 (27A), 

Little Falls, Minnesota, FHWA, Pavement Performance Division, January 1996. 

LTPP Seasonal Monitoring Program, Site Installation Report for GPS Section 271028 (27B), 

Detroit Lakes, Minnesota, FHWA, Pavement Performance Division, January 1996. 

LTPP Seasonal Monitoring Program, Site Installation Report for GPS Section 274040 (27D), 

Grand Rapids, Minnesota, FHWA, Pavement Performance Division, February 1996. 

LTPP Seasonal Monitoring Program, Site Installation Report for GPS Section 276251 (27C), 

Bemidji, Minnesota, FHWA, Pavement Performance Division, January 1996. 

LTPP Seasonal Monitoring Program, Site Installation Report for SPS Section 310114 (31A), 

Hebron, Nebraska, FHWA, Pavement Performance Division, February 1996. 

LTPP Seasonal Monitoring Program, Site Installation Report for GPS Section 313018 (31B), 

Kearney, Nebraska, FHWA, Pavement Performance Division, February 1996. 

LTPP Seasonal Monitoring Program, Site Installation Report for SPS Section 460804 (46A), 

Pollock, South Dakota, FHWA, Pavement Performance Division, February 1996. 

LTPP Seasonal Monitoring Program, Site Installation Report for GPS Section 469187 (46B), 

Faith, South Dakota, FHWA, Pavement Performance Division, February 1996. 

LTPP Seasonal Monitoring Program, Site Installation Report for GPS Section 831801 (83A), 

Oak Lake, Manitoba, FHWA, Pavement Performance Division, January 1996. 

LTPP Seasonal Monitoring Program, Site Installation Report for GPS Section 833802 (83B), 

Glenea, Manitoba, FHWA, Pavement Performance Division, January 1996. 

LTPP Seasonal Monitoring Program, Site Installation Report for GPS Section 906405 (90A), 

Plunkett, Saskatchewan, FHWA, Pavement Performance Division, January 1996. 

136 
A.10.3.3 Southern Region 

LTPP Seasonal Monitoring Program: Site Installation and Initial Data Collection, Section 

010102, Opelika, Alabama, FHWA, Pavement Performance Division, February 1996. 

LTPP Seasonal Monitoring Program: Site Installation and Initial Data Collection, Section 

131005, Warner Robins, Georgia, FHWA, Pavement Performance Division, February 1996. 

LTPP Seasonal Monitoring Program: Site Installation and Initial Data Collection, Section 

131031, Dawsonville, Georgia, FHWA, Pavement Performance Division, February 1996. 

LTPP Seasonal Monitoring Program: Site Installation and Initial Data Collection, Section 

133019, Gainesville, Georgia, FHWA, Pavement Performance Division, February 1996. 

LTPP Seasonal Monitoring Program: Site Installation and Initial Data Collection, Section 

281016, Kosciusko, Mississippi, FHWA, Pavement Performance Division, February 1996. 

LTPP Seasonal Monitoring Program: Site Installation and Initial Data Collection, Section 

281802, Laurel, Mississippi, FHWA, Pavement Performance Division, February 1996. 

LTPP Seasonal Monitoring Program: Site Installation and Initial Data Collection, Section 

351112, Hobbs, New Mexico, FHWA, Pavement Performance Division, March 1995. 

LTPP Seasonal Monitoring Program: Site Installation and Initial Data Collection, Section 

404165, Cleo Springs, Oklahoma, FHWA, Pavement Performance Division, March 1995. 

LTPP Seasonal Monitoring Program: Site Installation and Initial Data Collection, Section 

481060, Victoria, Texas, FHWA, Pavement Performance Division, March 1995. 

LTPP Seasonal Monitoring Program: Site Installation and Initial Data Collection, Section 

481068, Paris, Texas, FHWA, Pavement Performance Division, February 1995. 

LTPP Seasonal Monitoring Program: Site Installation and Initial Data Collection, Section 

481077, Estelline, Texas, FHWA, Pavement Performance Division, January 1995. 

LTPP Seasonal Monitoring Program: Site Installation and Initial Data Collection, Section 

481122, Floresville, Texas, FHWA, Pavement Performance Division, March 1995. 

LTPP Seasonal Monitoring Program: Site Installation and Initial Data Collection, Section 

483739, Kingsville, Texas, FHWA, Pavement Performance Division, March 1995. 

LTPP Seasonal Monitoring Program: Site Installation and Initial Data Collection, Section 

484142, Jasper, Texas, FHWA, Pavement Performance Division, February 1995. 

LTPP Seasonal Monitoring Program: Site Installation and Initial Data Collection, Section 

484143, Beaumont, Texas, FHWA, Pavement Performance Division, March 1995. 

137 
A.10.3.4 Western Region 

LTPP Seasonal Monitoring Program: Site Installation and Initial Data Collection, Section 

040113, Kingman, Arizona, Publication No. FHWA-04-0113, FHWA, Pavement Performance 

Division, May 1997. 

LTPP Seasonal Monitoring Program: Site Installation and Initial Data Collection, Section 

040114, Kingman, Arizona, Publication No. FHWA-04-0114, FHWA, Pavement Performance 

Division, May 1997. 

LTPP Seasonal Monitoring Program: Site Installation and Initial Data Collection, Section 

040215, Kingman, Arizona, Publication No. FHWA-04-0215, FHWA, Pavement Performance 

Division, May 1997. 

LTPP Seasonal Monitoring Program: Site Installation and Initial Data Collection, Section 

041024, Flagstaff, Arizona, Publication No. FHWA-04-1024, FHWA, Pavement Performance 

Division, May 1997. 

LTPP Seasonal Monitoring Program: Site Installation and Initial Data Collection, Section 

063042, Lodi, California, Publication No. FHWA-06-3042, FHWA, Pavement Performance 

Division, May 1997. 

LTPP Seasonal Monitoring Program: Site Installation and Initial Data Collection, Section 

081053, Delta, Colorado, Publication No. FHWA-08-1053, FHWA, Pavement Performance 

Division, January 1994. 

LTPP Seasonal Monitoring Program: Site Installation and Initial Data Collection, Section 

161010, Idaho Falls, Idaho, Publication No. FHWA-16-1010, FHWA, Pavement Performance 

Division, February 1994. 

LTPP Seasonal Monitoring Program: Site Installation and Initial Data Collection, Section 

300114, Great Falls, Montana, Publication No. FHWA-30-0114, FHWA, Pavement 

Performance Division, October 2001. 

LTPP Seasonal Monitoring Program: Site Installation and Initial Data Collection, Section 

320101, Battle Mountain, Nevada, Publication No. FHWA-32-0101, FHWA, Pavement 

Performance Division, June 1997. 

LTPP Seasonal Monitoring Program: Site Installation and Initial Data Collection, Section 

320204, Battle Mountain, Nevada, Publication No. FHWA-32-0204, FHWA, Pavement 

Performance Division, June 1997. 

LTPP Seasonal Monitoring Program: Site Installation and Initial Data Collection, Section 

491001, Bluff, Utah, Publication No. FHWA-49-1001, FHWA, Pavement Performance 

Division, February 1994. 

138 
LTPP Seasonal Monitoring Program: Site Installation and Initial Data Collection, Section 

493011, Nephi, Utah, Publication No. FHWA-49-3011, FHWA, Pavement Performance 

Division, February 1994. 

LTPP Seasonal Monitoring Program: Site Installation and Initial Data Collection, Section 

533813, Camas, Washington, Publication No. FHWA-53-3813, FHWA, Pavement Performance 

Division, May 1997. 

 

LTPP Seasonal Monitoring Program: Site Installation and Initial Data Collection, Section 

561007, Cody, Wyoming, Publication No. FHWA-56-1007, FHWA, Pavement Performance 

Division, February 1994. 

Seasonal Instrumentation Pilot Study, Instrumentation Installation, Section 163023 in Idaho,

SHRP, May 1992. 

Seasonal Instrumentation Pilot Study, Instrumentation Installation, Montana Section 308129, 

FHWA, Pavement Performance Division, December 1992. 

139 
APPENDIX B. EXPERIMENT DEFINITIONS 

B.1 GPS EXPERIMENTS 

B.1.1 GPS-1: Asphalt Concrete on Granular Base 

Pavements in the GPS-1 experiment include a dense-graded hot-mix asphalt concrete (HMAC) 

surface layer, with or without other HMAC layers, constructed over an untreated granular base or

no base. One or more subbase layers may be present, but are not required. A treated subgrade is 

classified as a subbase layer. Full-depth AC pavements (defined as an HMAC surface layer 

combined with one or more subsurface HMAC layers beneath the surface layer, with a minimum 

total HMAC thickness of 152 mm (6 inches), placed directly on a treated or untreated subgrade) 

are also allowed in this study. 

Seal coats or porous friction courses are allowed on the surface, but not in combination with each

other (e.g., a porous friction course placed over a seal coat is not acceptable). Seal coats are 

permissible on top of granular base layers. At least one layer of dense-graded HMAC is required, 

regardless of the existence of seal coats or porous friction courses. 

B.1.2 GPS-2: Asphalt Concrete on Bound Base 

Pavements in the GPS-2 experiment consist of a dense-graded HMAC surface layer, with or 

without other HMAC layers, placed over a bound base layer. Bound bases are defined as those in 

which the cementing action of the stabilizing material is used to improve the structural 

characteristics of the base material. Binder types used in the base include bituminous and 

nonbituminous (pozzolans, PCC, lime, etc.). One or more subbase layers can be present, but are 

not required. Seal coats or porous friction courses are permitted on the surface, but not in 

combination (e.g., a porous friction course placed over a seal coat is not acceptable). 

B.1.3 GPS-3: Jointed Plain Concrete Pavement (JPCP) 

Pavements in the GPS-3 experiment consist of jointed plain (i.e., unreinforced) PCC slabs placed 

over either stabilized or unbound granular base layer. One or more subbase layers can be present, 

but are not required. A seal coat (prime coat) is permissible just above a granular base layer. The 

joints can include either no load-transfer devices or smooth dowel bars; however, jointed slabs 

with load-transfer devices other than dowel bars are accepted in the study on a case-by-case basis 

only. Slabs placed directly on a treated or untreated subgrade are not acceptable. 

B.1.4 GPS-4: Jointed Reinforced Concrete Pavement (JRCP) 

Pavements in the GPS-4 experiment include jointed reinforced PCC pavements with doweled 

joints spaced less than 13 m (40 ft) apart. The PCC slab must rest on a base layer or on 

unstabilized coarse-grained subgrade soils. A base layer and one or more subbase layers may 

exist, but are not required. JRCP placed directly on a fine-grained soil/aggregate layer or finegrained subgrades is excluded from this study. JRCP’s without load-transfer devices or with 

devices other than smooth dowel bars at the joints are not acceptable. 

140 
B.1.5 GPS-5: Continuously Reinforced Concrete Pavement (CRCP) 

Pavements in the GPS-5 experiment include continuously reinforced PCC pavements placed 

directly on a base layer or on unstabilized coarse-grained subgrade. One or more subbase layers 

can exist, but are not required. A seal coat (prime coat) is permissible just above a granular base 

layer. CRCP placed directly on a fine-grained soil/aggregate layer or fine-grained subgrades is 

not acceptable. 

B.1.6 GPS-6: Asphalt Concrete Overlay of Asphalt Concrete Pavement 

Pavements in the GPS-6A, -6B, -6C, -6D, and -6S experiments include a dense-graded HMAC 

surface layer, with or without other HMAC layers, placed over an existing AC pavement. 

The designation 6A refers to those sections that were overlaid prior to acceptance in the GPS 

program. 

The 6B, 6C, 6D, and 6S designations refer to LTPP sections on which an overlay was placed 

after the section had been accepted into the LTPP program. 

Seal coats or porous friction courses are allowed, but not in combination. Fabric interlayers and 

stress-absorbing membrane interlayers (SAMIs) are permitted between the original surface and 

the overlay. The total thickness of HMAC used in the overlay is required to be at least 25.4 mm

(1.0 inch). 

B.1.7 GPS-7: Rehabilitated Portland Cement Concrete Pavement 

Pavements in the GPS-7A, -7B, -7C, -7D, -7F, -7R, and -7S experiments primarily consist of 

JPCP, JRCP, or CRCP pavements in which a dense-graded HMAC surface layer, with or without 

other HMAC surface layers, was constructed. 

The exception is the 7R designation that was added to account for PCC pavement test sections 

rehabilitated using concrete pavement restoration techniques. (To date, no test sections have been 

designated as 7R.) 

The designation 7A refers to sections that were overlaid prior to acceptance in the GPS program. 

The 7B, 7C, 7D, 7F, and 7S designations refer to those test sections on which an overlay was 

placed after the section had been accepted into the LTPP program. 

The PCC slab may rest on a combination of base and/or subbase layers. The existing concrete 

slab can also be placed directly on lime- or cement-treated, fine- or coarse-grained subbase or on 

untreated coarse-grained subgrade soil. Slabs placed directly on untreated fine-grained subgrade 

are not acceptable. 

Seal coats or porous friction courses are permissible, but are not allowed in combination. Fabric 

interlayers and SAMIs are acceptable when placed between the original surface (concrete) and 

141 
the overlay. Overlaid pavements involving aggregate interlayers and open-graded AC interlayers 

are not included in this study. The total thickness of HMAC used in the overlay is required to be 

at least 38 mm (1.5 inches). 

B.1.8 GPS-9: Unbound PCC Overlays of PCC

Pavements acceptable in the GPS-9 experiment include unbonded JPCP, JRCP, or CRCP 

overlays with a thickness of 129 mm (5 inches) or more placed over an existing JPCP, JRCP, or 

CRCP pavement. An interlayer used to prevent bonding of the existing slab and the overlay slab 

is required. The overlaid concrete pavement can rest on a base and/or subbase, or directly on the 

subgrade. 

B.2 SPS EXPERIMENTS 

The following definitions apply solely to the core sections within each experiment. Any 

supplemental sections constructed at each SPS project are based on the highway agency’s 

research interests. These sections are not consistent from one agency to the next. 

B.2.1 SPS-1: Structural Factors for Flexible Pavements 

The experiment on the structural factors for flexible pavements (SPS-1) examines the 

performance of specific AC-surfaced pavement structural factors under different environmental 

conditions. Pavements within SPS-1 must start with the original construction of the entire 

pavement structure or removal and complete reconstruction of an existing pavement. The 

pavement structural factors in this experiment include the in-pavement drainage layer, surface 

thickness, base type, and base thickness. The experiment design stipulates a traffic loading level 

in the study lane in excess of 100,000 80-kN (18-kip) ESALs per year. The combination of the 

study factors in this experiment results in 24 different pavement structures. The experiment is 

designed using a fractional factorial approach to enhance implementation practicality, permitting 

the construction of 12 test sections at one site and a complementary 12 test sections to be 

constructed at another site within the same climatic region on a similar subgrade type. 

B.2.2 SPS-2: Structural Factors for Rigid Pavements 

The experiment on the structural factors for rigid pavements (SPS-2) examines the performance 

of specific JPCP structural factors under different environmental conditions. Pavements within 

SPS-2 must start with the original construction of the entire pavement structure or removal and 

complete reconstruction of an existing pavement. The pavement structural factors included in 

this experiment are in-pavement drainage layer, PCC surface thickness, base type, PCC flexural 

strength, and lane width. The experiment requires that all test sections be constructed with 

perpendicular doweled joints at 4.9-m (15-ft) spacing and stipulate a traffic loading level in the 

lane in excess of 200,000 ESALs/year. The experiment is designed using a fractional factorial 

approach to enhance implementation practicality, permitting the construction of 12 test sections 

at one site and a complementary 12 test sections to be constructed at another site within the same

climatic region on a similar subgrade type. 

142 
B.2.3 SPS-3: Preventive Maintenance Effectiveness of Flexible Pavements 

The experiment on the preventive maintenance effectiveness of flexible pavements (SPS-3) 

examines the performance of four preventive maintenance treatments (crack seal, chip seal, 

slurry seal, and thin overlay) on AC surface pavement sections within the four climatic regions 

on the two classes of subgrade soil. The experiment design stipulates that the effectiveness of 

each of the four treatments be evaluated independently. The effectiveness of combinations of 

treatments is not considered. Therefore, each test site includes four treated test sections in 

addition to a control section. In most cases, the control (or “do nothing”) section is classified as a 

GPS test section. 

B.2.4 SPS-4: Preventive Maintenance Effectiveness of Rigid Pavements 

The experiment on the preventive maintenance effectiveness of rigid pavements (SPS-4) was 

designed to study the effects of crack/joint sealing and undersealing on jointed PCC pavement 

structures. Both JRCP and JPCP are included in the study. Undersealing is included as an 

optional factor and is only performed on a section in which the need for undersealing is 

indicated. The experiment design stipulates that the effectiveness of each of the two treatments 

be evaluated independently. The effectiveness of combinations of treatments is not considered. 

Each test site includes two treated test sections and a control section. The treatment sections on 

joint-/crack-sealing test sites consist of one section in which all joints have no sealant and one in 

which a watertight seal is maintained on all cracks and joints.

B.2.5 SPS-5: Rehabilitation of Asphalt Concrete Pavements 

The experiment on the rehabilitation of AC pavements (SPS-5) examines the performance of 

eight combinations of AC overlays on existing AC-surfaced pavements. The rehabilitation 

treatment factors included in the study are the intensity of surface preparation, recycled versus 

virgin AC overlay mixture, and overlay thickness. The experiment design includes all four 

climatic regions and the condition of the existing pavement. The experiment design stipulates a 

traffic loading level in the study lane in excess of 100,000 80-kN (18-kip) ESALs/year. 

B.2.6 SPS-6: Rehabilitation of Jointed Portland Cement Concrete (JPCC) Pavements 

The experiment on the rehabilitation of JPCC pavements (SPS-6) examines the performance of 

seven rehabilitation treatment options as a function of the climatic region, type of pavement 

(plain or reinforced), and the condition of the existing pavement. The rehabilitation methods 

include surface preparation (limited preparation or full concrete pavement restoration) with a 

102-mm- (4-in-) thick AC overlay or without an overlay, crack/break and seat with two AC 

overlay thicknesses (102 or 203 mm (4 or 8 inches)), and limited surface preparation with a 102-

mm- (4-in-) thick AC overlay with sawed and sealed joints. 

B.2.7 SPS-7: Bonded Concrete Overlays of Concrete Pavements 

The experiment on the bonded concrete overlays of concrete pavements (SPS-7) examines the 

performance of eight combinations of bonded PCC treatment alternatives as a function of the 

143 
climatic region, pavement type (jointed or continuously reinforced), and the condition of the 

existing pavement. The rehabilitation treatment factors include combinations of surface 

preparation methods (cold milling plus sand-blasting and shot-blasting), bonding agents (neat 

cement grout or none), and overlay thicknesses (76 or 127 mm (3 or 5 in)). The experiment 

design stipulates a traffic loading level in the study lane in excess of 200,000 80-kN (18-kip) 

ESALs/year. Only four SPS-7 projects were constructed. 

B.2.8 SPS-8: Environmental Effects in the Absence of Heavy Loads 

The experiment on the environmental effects in the absence of heavy loads (SPS-8) examines the 

effects of climatic factors in the four environmental regions and on the subgrade types (frostsusceptible, expansive, fine, and coarse) on pavement sections incorporating flexible and rigid 

pavement designs that are subjected to limited traffic loading. The experiment design requires 

either two flexible pavement or two rigid pavement structures to be constructed at each site. The 

two flexible pavement sections consist of a 102-mm (4-inch) AC surface on a 203-mm- (8-in-) 

thick untreated granular base and a 178-mm (7-inch) AC surface over a 305-mm- (12-in-) thick 

granular base. Rigid pavement test sections consist of doweled JPCP with a 203-mm (8-inch) 

and 279-mm (11-inch) PCC surface thickness on 152-mm- (6-in-) thick dense-graded granular 

base. The pavement structures included in this study match pavement structures included in the 

SPS-1 and -2 experiments. The experiment design stipulates that traffic volume in the study lane 

be at least 100 vehicles per day, but not more than 10,000 80-kN (18-kip) ESALs/year. The 

flexible and rigid pavement sections may be constructed at the same site or at different sites. 

B.2.9 SPS-9: Validation of SHRP Asphalt Specifications and Mix Design 

SPS-9P was a pilot effort started at the end of the SHRP program to get some experience in 

implementing the Superpave specifications. Test sections classified as SPS-9P were constructed 

using a very limited set of guidelines. In some instances, specifications were based on interim

Superpave specifications that were changed at a later date. Many of these test sections were 

constructed before materials sampling and testing guidelines were established. 

The SPS-9A experiment, Superpave Asphalt Binder Study, requires construction of a minimum 

of two test sections at each project site. Construction can include new construction, 

reconstruction, or overlay. The minimum test sections consist of the highway agencies’ standard 

mix, the Superpave level 1 designed standard mix, and the Superpave mix with an alternate 

binder grade either higher or lower than the specified Superpave binder. The minimum of two 

test sections at some sites results from the agency’s declaration that the Superpave test section is 

the same as the standard agency mix. This will provide the opportunity to evaluate and improve 

the practical aspects of implementing the Superpave mix design by: (1) a hands-on field trial by 

interested highway agencies, (2) a comparison of the performance of the Superpave mixes 

against mixes designed using current highway agencies’ asphalt specifications, (3) asphaltaggregate specifications and mix design procedures, and (4) testing of the sensitivity of the 

Superpave asphalt binder specifications relative to low-temperature cracking, fatigue, or 

permanent deformation distress factors. 

144 

APPENDIX C. DATA EXTRACTION EXAMPLES 

This appendix contains two data extraction examples. They illustrate productive practices for 

dealing with data from the LTPP database using the SQL. These examples provide one method 

for organizing data from an RDBMS. Some software packages provide other methods of 

querying data, such as the query interface in Microsoft Access 2000. 

For those unfamiliar with SQL, a reference book on SQL is highly recommended. The SQL 

statements that follow have been written for and tested with Microsoft Access 2000. Some of 

them, especially the ones that make use of aliasing and subqueries, will need to be modified for 

use with previous versions of Microsoft Access. In addition, those that use domain aggregate 

functions may need slight modifications for use with RDBMS’s such as Oracle. 

C.1 SMP DATA 

In the following example, we will extract the data necessary to track air temperature, 

precipitation, and subsurface temperature on an hourly basis for a single section for a period of 

one week. The section of choice is 360801, a test section in the SPS-8 experiment located in 

New York. The time period being selected is March 1-8, 1996. 

C.1.1 Ambient Temperature and Precipitation 

First of all, we will need the ambient air temperature and precipitation. Since we want hourly 

data, we need to go to SMP_ATEMP_RAIN_HOUR. The required query is straightforward: 

SELECT smp_date, atemp_rain_time, avg_hour_air_temperature, rain_hour 

FROM smp_atemp_rain_hour 

WHERE state_code = 36 

AND shrp_id = ‘0801’ 

AND smp_date BETWEEN #3/01/1996# AND #3/08/1996#; 

The first 10 rows of the 192 rows in the result set are as follows: 

smp_date atemp_rain_time avg_hour_air_temperature rain_hour

3/01/1996 0100 -8.3 0

3/01/1996 0200 -7.6 0

3/01/1996 0300 -7.5 0

3/01/1996 0400 -7.3 0

3/01/1996 0500 -7.3 0

3/01/1996 0600 -7.3 0

3/01/1996 0700 -7.8 0

3/01/1996 0800 -7.8 0

3/01/1996 0900 -6.2 0

3/01/1996 1000 -4.8 0

The time is in a 24-hour military-style string format, the temperature is in degrees Celsius, and 

the precipitation is in millimeters. 

146 
C.1.2 Subsurface Temperatures 

Next, we need to get the subsurface temperatures. This will require a join, since the temperatures

themselves and the depth at which they were taken are stored in separate tables. The necessary 

query is: 

SELECT smp_date, temperature_time, avg_hour_temperature, therm_depth 

FROM smp_mrctemp_auto_hour a, smp_mrctemp_depths b 

WHERE a.state_code = 36 

AND a.shrp_id = ‘0801’ 

AND a.state_code = b.state_code 

AND a.shrp_id = b.shrp_id 

AND a.therm_no = b.therm_no 

AND smp_date BETWEEN #3/01/1996# AND #3/08/1996#; 

The first 10 rows of the 960 rows in the result set are as follows: 

smp_date temperature_time avg_hour_temperature therm_depth

3/01/1996 2400 -4.7 0.025

3/04/1996 2200 -3.1 0.025

3/03/1996 0600 -5.4 0.025

3/08/1996 1700 -1.9 0.025

3/02/1996 0100 -4.9 0.025

3/08/1996 1800 -3.5 0.025

3/05/1996 2200 -1.7 0.025

3/08/1996 1900 -5.0 0.025

3/08/1996 1500 0.5 0.025

3/08/1996 2000 -5.6 0.025

The time is in a 24-hour military-style string format, the temperature is in degrees Celsius, and 

the depth is in meters from the pavement surface. 

C.1.3 Subsurface Moisture 

Subsurface moisture data are only available in approximately monthly intervals. A quick query 

of SMP_TDR_MOISTURE_AUTO will reveal that there is no subsurface moisture data 

available between 3/01/1996 and 3/08/1996. The following query can be conducted to determine 

which dates are available:

SELECT DISTINCT smp_date 

FROM smp_tdr_auto_moisture 

WHERE state_code = 36 

AND shrp_id = ‘0801’ 

AND smp_date BETWEEN #2/01/1996# AND #4/01/1996#; 

The result set is as follows: 

smp_date

2/08/1996

147 
smp_date

3/11/1996

3/26/1996

We can then extract the moisture gradient for the day closest to our time period as follows: 

SELECT smp_date, tdr_time, gravimetric_moisture_content, tdr_depth 

FROM smp_tdr_auto_moisture a, smp_tdr_depths_length b 

WHERE a.state_code = b.state_code 

AND a.shrp_id = b.shrp_id 

AND a.tdr_no = b.tdr_no 

AND a.smp_date = #3/11/1996# 

The result set is as follows: 

smp_date tdr_time gravimetric_moisture_content tdr_depth

3/11/1996 1206 4.1 0.24

3/11/1996 1207 14.6 0.39

3/11/1996 1207 18.9 0.54

3/11/1996 1210 16.5 1.13

3/11/1996 1210 15.6 1.30

3/11/1996 1211 17.3 1.61

The time is in a 24-hour military-style string format, the gravimetric moisture content is in 

percent by weight of dry soil, and the depth is in meters from the pavement surface. 

C.1.4 Electrical Resistance and Resistivity 

Like subsurface moisture gradients, electrical resistance and resistivity measurements are only 

available in approximately monthly intervals. To determine the available dates, we can run the 

following query: 

SELECT DISTINCT smp_date 

FROM smp_eresist_man_contact 

WHERE state_code = 36 

AND shrp_id = ‘0801’ 

AND smp_date BETWEEN #2/01/1996# AND #5/01/1996# 

The query returns the following result set: 

smp_date

2/08/1996

4/09/1996

Since 2/08/1996 is marginally closer to our target date, we will use that date. However, you 

should note that these tests are commonly conducted twice during a given day, as can be shown 

in the following query: 

SELECT DISTINCT smp_date, COUNT(*) as num_repetitions 

FROM smp_eresist_man_contact 

GROUP BY smp_date, electrode_start; 

148 
The result set is: 

smp_date num_repetitions

2/08/1996 2

4/09/1996 2

This query shows that the resistance was measured across all of the electrodes twice during each 

day. We will look at the data collected in the afternoon. Electrical resistivity measurements are 

taken between electrodes at different depths. We will treat the depth at which the measurement 

was taken as the mean depth between the two electrodes. The query is as follows: 

SELECT g.avg_depth, contact_resistance, bulk_resistivity 

FROM 

(SELECT contact_resistance, (depth_1 + depth_2)/2 as avg_depth 

FROM 

(SELECT elct_depth as depth_1, electrode_start, resistance as 

contact_resistance 

FROM smp_eresist_man_contact a, smp_eresist_depths b 

WHERE a.electrode_start = b.electrode_no 

AND a.state_code = b.state_code 

AND a.shrp_id = b.shrp_id 

AND a.state_code = 36 

AND a.shrp_id = ‘0801’ 

AND smp_date = #2/08/1996# 

AND VAL(eresist_time) > 1200) c, 

(SELECT elct_depth as depth_2, electrode_start 

FROM smp_eresist_man_contact d, smp_eresist_depths e 

WHERE d.electrode_end = e.electrode_no 

AND d.state_code = e.state_code 

AND d.shrp_id = e.shrp_id 

AND d.state_code = 36 

AND d.shrp_id = ‘0801’ 

AND smp_date = #2/08/1996# 

AND VAL(eresist_time) > 1200) f 

WHERE c.electrode_start = f.electrode_start) g, 

(SELECT bulk_resistivity, (depth_1 + depth_2)/2 as avg_depth 

FROM 

(SELECT elct_depth as depth_1, eamp_start, resistivity as 

bulk_resistivity 

FROM smp_eresist_man_4point h, smp_eresist_depths i 

WHERE h.eamp_start = i.electrode_no 

AND h.state_code = i.state_code 

AND h.shrp_id = i.shrp_id 

AND h.state_code = 36 

AND h.shrp_id = ‘0801’ 

AND smp_date = #2/08/1996# 

AND VAL(eresist_time) > 1200) j, 

(SELECT elct_depth as depth_2, eamp_start 

FROM smp_eresist_man_4point k, smp_eresist_depths l 

WHERE k.eamp_end = l.electrode_no 

AND k.state_code = l.state_code 

AND k.shrp_id = l.shrp_id 

AND k.state_code = 36 

AND k.shrp_id = ‘0801’ 

AND smp_date = #2/08/1996# 

AND VAL(eresist_time) > 1200) m 

WHERE j.eamp_start = m.eamp_start) n 

WHERE g.avg_depth BETWEEN n.avg_depth - 0.01 AND n.avg_depth + 0.01; 

149 
The result set is as follows: 

avg_depth contact_resistance bulk_resistivity

0.3035 396 13

0.354 243 13

0.4045 256 12

0.4555 298 10

0.5065 342 14

0.557 598 13

0.6075 954 22

0.6585 757 15

0.7095 466 23

0.76 443 14

0.8105 416 17

0.8615 384 15

0.912 414 18

0.963 475 15

1.014 525 20

1.064 506 15

1.115 479 18

1.1665 412 18

1.217 398 17

1.268 453 17

1.3195 468 19

1.37 323 17

1.42 218 17

1.4705 222 16

1.5205 222 16

1.572 223 14

1.6235 218 16

1.6725 227 14

1.723 252 15

1.775 262 15

1.8265 251 13

1.8765 223 14

1.9265 203 13

The depth is in meters below the pavement surface, the contact resistance is in ohms, and the 

bulk resistivity is in ohm-meters. The above query is quite complex since it uses four nested 

subqueries. When dealing with such queries, always be certain that they are working as intended 

before relying on the results. A good method for checking such queries is to determine ahead of 

time how many records should be returned and then cross-check that number against the actual 

number of records returned. Also, each subquery can be run and examined on its own before 

assembling them. 

150 
C.2 BACKCALCULATION 

This example outlines a typical data extraction that involves queries of deflection and materials 

tables for data in support of backcalculation analysis to determine the elastic layer moduli of 

flexible pavements. The SQL statements required for this task illustrate a relatively complex set 

of instructions involving the linkage of tables from a variety of database modules. It requires 

careful evaluation of the tables to ensure that the correct data are used for the purpose. 

The minimum requirements for data in order to support backcalculation analysis are: 

• Deflection measurements. 

• Layer thicknesses. 

• Supporting materials information. 

• Pavement temperatures. 

In this example, we will perform the data extraction in the following sequence: 

• Extract deflection data, including pavement temperatures and the date of the tests, from

MON_DEFL tables. 

• Use the deflection test date to tie the deflection measurements to the proper construction 

number (CONSTRUCTION_NO) via the EXPERIMENT_SECTION table. 

• Extract the applicable pavement layer data and material properties from tables in the TST 

and INV modules based on the STATE_CODE, SHRP_ID, and CONSTRUCTION_NO 

fields. 

C.2.1 MON_DEFL Database Tables 

Since deflection test data are distributed among a number of related tables in the MON_DEFL 

submodule, it is necessary to familiarize oneself with it before attempting to extract data. 

Prominent tables in the submodule include MON_DEFL_DROP_DATA, which contains the 

drop heights, load, and measured deflections for each FWD drop, and 

MON_DEFL_LOC_INFO, which contains the location information for the drops. The two tables 

are related through the STATE_CODE, SHRP_ID, TEST_DATE, and TEST_TIME fields. The 

offsets of each FWD geophone sensor are in MON_DEFL_DEV_SENSORS, which can be 

related to MON_DEFL_LOC_INFO through the CONFIGURATION_NO field. 

Pavement temperatures that were measured during each FWD test can be extracted from the 

MON_DEFL_TEMP_VALUES and MON_DEFL_TEMP_DEPTHS tables, which are related to

the previously discussed tables and to each other through the STATE_CODE, SHRP_ID, and 

TEST_DATE fields. 

Information about the relationships among all database tables can be found within the Table 

Navigator software. It is recommended that the software be consulted before attempting any 

extraction of data from the LTPP database. 

151 
C.2.2 Temperature Tables 

For sections within SMP, subsurface temperatures can be extracted from the 

SMP_MRCTEMP_* tables. However, temperature gradients in the pavement surface layer are 

also manually collected during FWD testing for both SMP and non-SMP test sections. These 

pavement temperature readings were taken at regular 30- to 60-minute intervals during deflection 

testing at each LTPP site and are stored within the MON_DEFL_TEMPS_DEPTHS and 

MON_DEFL_TEMPS_VALUES tables. We will have to extract the temperatures, depths, and 

times into a single table and the deflection values, deflection test locations, and times into 

another table. An interpolation process must then be used to estimate the temperature gradient

present within the AC pavement layers at the time of the actual deflection test. Assuming that we

want data from site 341003 for a test conducted on 3/11/99, the required SQL statement is: 

SELECT d.shrp_id, d.state_code, d.test_date, layer_temp_depth_1, 

layer_temperature_1, time_layer_temp, d.point_loc 

FROM mon_defl_temp_depths d, mon_defl_temp_values v 

WHERE d.state_code = v.state_code 

AND d.shrp_id = v.shrp_id 

AND d.test_date = v.test_date 

AND d.point_loc = v.point_loc and d.state_code = 34 

AND d.shrp_id = ‘1003’ 

AND d.test_date = #3/11/1999# 

ORDER BY v.time_layer_temp, d.point_loc; 

For the purpose of brevity, only the first depth at which the temperature was measured is queried. 

To retrieve the other temperatures and their respective depths, simply add 

LAYER_TEMP_DEPTH_2, LAYER_TEMPERATURE_2, etc., to the SELECT statement. The 

partial result set is listed below:

state_code shrp_id test_date layer_temp_depth_1 layer_temperature_1 time_layer_temp point_loc

34 1003 3/11/1999 25 -1.4 910 -3

34 1003 3/11/1999 25 3.9 1015 -3

34 1003 3/11/1999 25 8.2 1125 -3

The depth is in millimeters, the temperature is in degrees Celsius, and the point location is in 

meters. 

C.2.3 Deflection Tables 

Having established the temperature gradient for FWD tests conducted on March 11, 1999, on 

LTPP test site 341003, the next step is to extract deflection values for the purpose of establishing 

the deflection basins. Data resulting from a single FWD test are distributed among five tables. 

The relationships between these tables are illustrated below.

The peak deflection values recorded by all sensors are stored within the 

MON_DEFL_DROP_DATA table. The sensor spacing figures can be extracted from 

MON_DEFL_DEV_SENSORS. A suitable SQL statement must be constructed to relate the 

tables so that the recorded deflection values can be matched to the appropriate sensor spacing. 

152 
153 

This can be done with the CONFIGURATION field from the MON_DEFL_LOC_INFO table. 

The first step is to extract the raw deflection data for the section and date in question, in this 

case, 341003 on March 11, 1999: 

SELECT state_code, shrp_id, test_date, test_time, defl_unit_id, point_loc, 

lane_no, drop_no, drop_load, peak_defl_1 

FROM mon_defl_drop_data 

WHERE state_code = 34 

AND shrp_id = ‘1003’ 

AND test_date = #3/11/1999#; 

For the purposes of clarity and brevity, this query was written to extract deflection data from

sensor 1 only. Obviously, it would need to be modified by the addition of PEAK_DEFL_2, etc., 

to the SELECT clause to fully characterize the deflection bowl shapes at each test location. A 

partial listing of the result set from that query is as follows: 
state_ 

code shrp_id test_date

test_ 

time defl_unit_id point_loc lane_no Drop_no drop_load peak_ defl_1

34 1003 3/11/1999 0852 8002-129 0 F1 1 384 156

34 1003 3/11/1999 0852 8002-129 0 F1 2 381 155

34 1003 3/11/1999 0852 8002-129 0 F1 3 387 156

34 1003 3/11/1999 0852 8002-129 0 F1 4 382 154

34 1003 3/11/1999 0852 8002-129 0 F1 5 606 234

34 1003 3/11/1999 0852 8002-129 0 F1 6 608 234

34 1003 3/11/1999 0852 8002-129 0 F1 7 610 234

34 1003 3/11/1999 0852 8002-129 0 F1 8 607 234

34 1003 3/11/1999 0852 8002-129 0 F1 9 805 300

34 1003 3/11/1999 0852 8002-129 0 F1 10 805 300

34 1003 3/11/1999 0852 8002-129 0 F1 11 806 300

34 1003 3/11/1999 0852 8002-129 0 F1 12 805 299

34 1003 3/11/1999 0852 8002-129 0 F1 13 1067 376

34 1003 3/11/1999 0852 8002-129 0 F1 14 1068 377

34 1003 3/11/1999 0852 8002-129 0 F1 15 1068 377

34 1003 3/11/1999 0852 8002-129 0 F1 16 1067 377

The table above represents a series of 16 drops at station 0+00 in the outer wheel path of LTPP 

site 341003 conducted at 8:52 a.m. on March 11, 1999. The drop load is in kilonewtons and the 

peak deflection is in micrometers. For this information to be of any use in backcalculation, we 

must also determine the offsets of the deflection sensors. To do this, we must first determine the 

CONFIGURATION_NO from the MON_DEFL_LOC_INFO table and then query the 

MON_DEFL_DEV_SENSORS table using this value as follows: 

SELECT DISTINCT a.configuration_no, sensor_no, center_offset 

FROM mon_defl_dev_sensors a, mon_defl_loc_info b 

WHERE a.configuration_no = b.configuration_no 

AND state_code = 34 

AND shrp_id = ‘1003’ 

AND test_date = #3/11/1999#; 

The result set from the above query is as follows: 

configuration_no sensor_no center_offset

100642 1 0

100642 2 203

100642 3 305

100642 4 457

100642 5 610

100642 6 914

100642 7 1524

The above query does not fully specify all of the key fields in MON_DEFL_LOC_INFO; 

however, this is generally not necessary. In the unlikely event that two different FWDs were 

154 
tested on the same section on the same day or that the unit changed configuration during the test 

(this would be evidenced by the query returning more than one record per sensor), the query 

should be further refined by specifying the DEFL_UNIT_ID and TEST_TIME. 

The EXPERIMENT_SECTION table indicates that on 4/08/1994, this site was assigned a 

CONSTRUCTION_NO = 2. With this information, we can extract the relevant layer 

information. 

C.2.4 Layer Information Tables 

Thus far, we have deflection and temperature information for the site, but have not extracted 

pavement layer and material properties. The database contains two types of layer information: 

agency-supplied layer information and LTPP-determined layer information. The agency-supplied 

information is not considered to be research-grade data, and we do not recommend that it be used 

for backcalculation purposes. However, this alternate source of information may be of use to 

researchers conducting indepth investigations of a specific section. For GPS test sections, this 

information is located in the INV_LAYER table. For SPS test sections, similar information is 

located in the SPS?_LAYER tables, where “?” is the SPS experiment number. The exceptions 

are the SPS-3 and -4 sections, which do not have this information. 

LTPP-determined layer thickness information is available from the TST_L05A and TST_L05B 

tables (TST_L05B is described in detail within the description of the Materials Testing module). 

The thicknesses recorded within these tables DO NOT necessarily match. The values within the

TST_L05A table are the measured thicknesses of layers either from materials sampled 

immediately before and/or immediately after the test section location or from elevation surveys. 

In some cases, notably for subgrade thicknesses, there are also numbers from shoulder probe 

samples taken midway along the section’s length. In contrast, the TST_L05B tables contain one 

field for a single representative thickness for each layer of the section. This value is derived from 

the measured values from the TST_L05A table and from analysis of the deflection data. It is a 

single subjective best estimate of a value that, in reality, is variable throughout the section’s 

length. A simple SQL statement to extract layer thickness information from TST_L05B is as 

follows: 

SELECT layer_no, inv_layer_no, description, layer_type, repr_thickness, 

matl_code, construction_no 

FROM tst_l05b 

WHERE state_code = 34 

AND shrp_id = ‘1003’; 

The result set is as follows: 

layer_no inv_layer_no description layer_type repr_thickness matl_code construction_no

1 1 7 SS 54.0 282 1

2 1 6 GS 24.9 308 1

3 2 5 GB 7.4 308 1

4 3 4 AC 5.9 1 1

5 4 3 AC 1.6 1 1

1 1 7 SS 54.0 282 2

155 
layer_no inv_layer_no description layer_type repr_thickness matl_code construction_no

2 1 6 GS 24.9 308 2

3 2 5 GB 7.4 308 2

4 3 4 AC 5.5 1 2

5 4 3 AC 0 1 2

6 1 AC 2.2 1 2

Because we did not specify a CONSTRUCTION_NO, we received two sets of layer information. 

The differences are attributable to a mill and AC overlay operation that occurred in 1994. (The 

type of operation can be determined by querying CN_CHANGE_REASON in the 

EXPERIMENT_SECTION table.) The thickness of layer 5 was reduced to 0, layer 4 was 

reduced in thickness, and layer 6 was added to the cross section of this site at that time. This 

example illustrates two important aspects of TST_L05B: 

• The lowest layer in the pavement structure always has a LAYER_NO equal to 1. 

• When a layer is removed by milling or grinding, it remains in TST_L05B, but with a 

thickness of 0. This is necessary for maintaining the relational integrity of the TST 

module. 

The deflection tests were conducted after the overlay date, so the layer information from 

CONSTRUCTION_NO = 2 should be used. 

C.2.5 Laboratory Materials Testing Data 

Any attribute of the materials used in the construction of these layers can be extracted from the 

appropriate table. For example, the following query retrieves the gradation of the unbound 

materials at this test section: 

SELECT layer_no, loc_no, sample_no, test_no, one_half_passing, no_10_passing, 

no_200_passing 

FROM tst_ss01_ug01_ug02 

WHERE state_code = 34 

AND shrp_id = ‘1003’; 

The result set from this query is as follows: 

layer_no loc_no sample_no test_no one_half_passing no_10_passing no_200_passing

2 BA* BG** 1 73 49 9.5

2 TP1 BG56 2 83 57 6.2

3 BA* BG** 1 76 45 8.9

3 TP1 BG55 2 75 49 11.0

Two observations can be made about this data. First, we have two different test results for the 

granular subbase (LAYER_NO = 2) and base layers (LAYER_NO = 3). How to resolve this is 

left up to the user of the data; however, the user should note that the tests with a TEST_NO of 1 

(TEST_NO is a code of the type TEST) are based on samples from the approach end of the 

156 
section, while those with a TEST_NO of 2 are from the leave end of the section (152- m (500-ft) 

apart). Also, samples with a LOC_NO like TP? are from test pits, while those with a LOC_NO

like BA? are from material extracted through a core hole. 

A more significant issue is that there is no information on the subgrade (LAYER_NO = 1). A 

fallback option is to check the agency-supplied data in INV_GRADATION with the following 

query: 

SELECT layer_no, one_half_passing, no_10_passing, no_200_passing 

FROM inv_gradation 

WHERE state_code = 34 

AND shrp_id = ‘1003’; 

The result set from this query is as follows: 

layer_no one_half_passing no_10_passing no_200_passing

1

2 5

3 70

4 100 7

Note that LAYER_NO in any INV table must be mapped as INV_LAYER_NO in TST_L05B. 

However, in this case, the agency did not supply any useful data. Our last resort for information 

on the subgrade is to use MATL _CODE in TST_L05B. Checking the LTPPDD, we find that 

MATL_CODE is a code of the type MATERIAL. Therefore, we can conduct the following 

query (this can also be done with the Table Navigator software): 

SELECT detail

FROM codes

WHERE codetype = ‘MATERIAL’

AND code = ‘282’; 

Our result is: 

detail 

Rock

This, of course, explains why we could not find any laboratory test information on this subgrade. 

Likewise, information about the AC layers may be of use in setting modulus seed values in 

backcalculation. The following query extracts useful information from TST_AC02, TST_AC03, 

and TST_AC04. 

SELECT a.layer_no, avg_bsg, avg_max_sg, (100 * (1 - (avg_bsg / avg_max_sg))) 

as air_voids, asphalt_content 

FROM 

(SELECT layer_no, AVG(bsg) as avg_bsg 

FROM tst_ac02 

WHERE state_code = 34 

AND shrp_id = ‘1003’ 

157 
GROUP BY state_code, shrp_id, layer_no) a, 

(SELECT layer_no, AVG(max_spec_gravity) as avg_max_sg 

FROM tst_ac03 

WHERE state_code = 34 

AND shrp_id = ‘1003’ 

GROUP BY state_code, shrp_id, layer_no) b, 

(SELECT layer_no, AVG(asphalt_content_mean) as asphalt_content 

FROM tst_ac04 

WHERE state_code = 34 

AND shrp_id = ‘1003’ 

GROUP BY state_code, shrp_id, layer_no) c 

WHERE VAL(a.layer_no) = VAL(b.layer_no) 

AND VAL(a.layer_no) = VAL(c.layer_no);

The VAL function is used here to work around an apparent bug in Microsoft Access’ data type

handling routine. The result set from this query is as follows: 

layer_no avg_bsg avg_max_sg air_voids asphalt_content

4 2.42516666666666666666667 2.542 4.59611854183058 4.4

5 2.3805 2.4845 4.18595290802978 5.85

6 2.386 2.5115 4.99701373681067 9

The above query shows the power of SQL to easily and quickly bring together data elements 

spread across different tables. The researcher may want to add count(*), min(*), max(*), and 

even stdev(*) functions where the avg(*) function is used to identify outliers, and as a general 

indication of data quality. Complex queries such as the one above should certainly be examined 

thoroughly to ensure that they function as intended. Because SPS sections are co-located and 

often share maximum specific gravity specimens between them, calculating air voids sometimes 

requires more finesse. 

158 

INDEX 

A

Administration module, 13 

Codes, 16 

Data Dictionary, 15 

Experiment Section, 13 

Admixtures, 40, 41 

Aggregate, 87, 90, 91 

Gradation, 92 

Shape, 87 

Air voids, 89 

Asphalt cement 

Bulk samples, 100 

Extraction, 86 

Penetration, 86 

Viscosity, 86 

Asphalt cement properties, 38, 39, 40, 71 

Asphalt concrete

Aggregate gradation, 87 

Air voids, 30, 31, 82, 85, 87, 89, 105 

Asphalt cement extraction, 86 

Coarse aggregate, 87 

Creep compliance, 83 

Fine aggregate, 87 

Fine aggregate shape, 87 

Indirect tensile strength, 83 

Moisture damage, 83 

Moisture susceptibility, 31, 82 

Remolded specimen, 101 

Resilient modulus, 83 

Asphalt Concrete core exam, 81 

Asphalt concrete overlay, 37 

Asphalt concrete properties, 38, 39

Asphalt content, 31, 38, 39, 82, 91

Asphalt emulsions, 90, 91 

Atterberg limits, 94 

Automated vehicle classification, 74 

Automated weather stations, 19 

Axle load distribution, 75 

B

Backcalculation, 51 

Base material, 92, 93, 94 

Benkelman beam, 63, 68, 69 

Bond shear strength, 89 

Bulk specific gravity asphalt concrete cores, 30, 31, 82, 85, 

87, 89, 105 

C

Chip seal, 68, 91, 92, 101, 142 

Climate data, 21

Codes, 16 

Coefficient of thermal expansion, 88 

Comments, 17 

Compaction, 31, 37, 41, 63, 64, 65, 66, 72, 83 

Compressive strength, 88 

Construction quality control, 66 

CONSTRUCTION_NO, 13, 105 

Continuously reinforced concrete pavement, viii, 4, 140 

Cost, 7, 30, 36, 42, 107 

Crack and seat, 5, 41 

Crack sealing, 11, 13, 36, 42, 66, 69, 100, 106 

Creep compliance, 83, 84, 85 

Curing, 31, 36, 40, 41, 42, 67, 68, 71 

Cut / fill locations, 64 

D

Data dictionary, 15 

Data release, 107 

DataPave, 108 

Date of material sampling, 97 

Deflection data 

Pavement temperature gradient, 8, 49, 51 

Peak deflections, 50 

Sensor spacing, 51 

Time history, 49

Deflection measurements, 49 

Delamination, 70

Density, 88, 93, 94 

Design mixture properties, 71 

Distress measurement, 43 

Drainage, 30, 42, 43, 53, 54, 64, 67, 141 

Dynaflect measurements, 70 

Dynamic load response, 10, 25 

E

Electrical resistivity, 16, 55, 58 

Equivalent single axle load, 75, 76, 141, 142, 143 

F

Faulting, 44 

FIELD_SET, 80, 82, 83, 85, 86, 87, 88, 89, 90, 91, 92, 93, 

94, 95, 97 

Flakiness index, 90 

Flexural strength, 89 

Freezing index, 24 

Friction, 11, 53 

FWD backcalculation, 51 

G

General pavement studies, viii, 2, 3, 9 

Experiments, 4 

Gradation, 30, 31, 37, 38, 39, 40, 41, 57, 67, 87, 91, 92, 93, 

156, 157 

Grinding, 36, 41, 42, 67, 71, 156

Grooving, 33, 36, 42 

Grout, 70, 143 

160 
H

Heater scarification, 41 

Hydraulic conductivity measurements, 94 

I

IMP_TYPE, 33, 34, 35, 37, 38, 39, 40, 41 

Indirect tensile strength, 83 

International Roughness Index, 49

Intersection, 64 

Inventory data, 29

J

Joint seal, 11, 30, 36, 42, 69, 101, 142 

Joint sealants 

Hot poured, 90 

Silicone, 90 

K

K-value, 93 

L

LAB_CODE, 81

Layer 

SPS, 63, 65 

TST module, 101, 102 

Link 

SPS project layers, 103 

SPS to GPS, 21, 23, 29, 64, 65 

TST layers to INV layers, 103 

Load transfer, 30, 40, 41, 44, 50, 60, 66, 67, 68, 71, 139 

Load transfer restoration, 41, 67 

LOC_NO, 97 

Location coordinates, 10, 29, 64, 65 

Location of material sampling, 97 

Longitudinal profile, 48 

Low temperature cracking, 43 

LTPP objectives, 1 

M

Maintenance data, 33 

Material classification, 93 

Material properties 

Air voids, 89 

Coefficient of thermal expansion, 88 

Compressive strength, 88, 92 

Creep compliance, 83 

Flexural strength, 89 

Indirect tensile strength, 83 

Modulus of elasticity, 89 

Modulus of subgrade reaction, 93

Permeability, 94

Resilient modulus, 83, 95 

Material sampling location, 97 

Material tests 

FIELD_SET, 80, 82, 83, 85, 86, 87, 88, 89, 90, 91, 92, 

93, 94, 95, 97 

SAMPLE_AREA, 80 

Test types and protocols, 77 

TEST_NO, 80, 82, 83, 85, 86, 87, 88, 89, 90, 91, 92, 93, 

94, 95, 97, 156 

Maxim specific gravity asphalt concrete cores, 82, 105 

Milling, 33, 36, 41, 42, 67, 70, 102, 143, 156 

MNT_IMP, 33, 35, 36, 42 

Modules, 10 

Modulus of elasticity, 89 

Modulus of subgrade reaction, 93

Moisture content, 88, 93, 94 

N

Nuclear density gauge, 88 

Nuclear density measurements, 67

O

Obtaining data, 107 

Operating weather station, 21 

Overlays, 33, 37, 38, 39, 40, 41, 43, 66, 67, 68, 70, 71, 77, 

80, 100, 102, 106, 140, 141, 142, 143, 156 

P

Patching, 11, 35, 36, 42, 43, 67, 68

Pavement performance database 

Introduction, 7 

Pavement temperature, 51, 56, 151 

Permeability, 94

Photographic images, 43 

Plant-mixed asphalt concrete, 30, 31, 34, 35, 37, 63, 64, 65, 

66, 67, 68, 71 

Portland cement concrete 

Air voids, 89 

Bond shear strength, 89 

Bulk specific gravity, 89 

Compressive strength, 88 

Core exam, 89 

Density, 89 

Flexural strength, 89 

Modulus of elasticity, 89 

Sampling, 101 

Tensile strength, 88 

Thermal coefficient, 88 

Portland cement concrete mixture properties, 40, 41

Portland cement concrete overlay, 3, 40, 41, 70, 71

Bonded, 3, 4, 70, 71, 115, 116, 122, 127, 128, 130, 142 

Unbonded, 4, 141 

Potential vertical rise, 94 

Profile measurement 

Longitudinal, 48, 49 

Transverse, 45, 47 

Profilograph, 67

R

Recycled asphalt concrete, 37, 38, 39, 40 

161 
Reflection cracking, 43 

Rehabilitation data, 33 

Reinforcing steel, 30, 40, 41, 68 

Resilient modulus 

Asphalt concrete, 83 

Unbound material, 95 

RHB_IMP, 11, 33, 35, 37 

Rubblization, 41

Rutting, 45, 48 

S

SAMPLE_AREA, 80 

SAMPLE_NO, 99 

Sand equivalency, 90 

Saw and seal, 70

Seal coat, 33, 36, 42, 139, 140 

Seasonal monitoring program, 11, 15, 55 

Air temperature and precipitation, 55, 145 

Frost, 58 

Joint opening and faulting, 60 

Measurement locations, 60 

moisture content, 56 

Pavement temperature gradient, 56 

Surface elevation, 59 

Water table, 59 

Shoulder, 34 

Shoulder drop off, 45 

SHRP_ID, 13, 105 

Slurry seal, 68, 91, 97, 101, 142 

Slurry seals, 90, 91 

Specific pavement studies, 2, 3, 9, 11, 63, 113, 114, 115, 

116, 117, 122, 131, 132 

Experiments, 4 

SPS-1, 2, 3, 4, 19, 25, 53, 63, 65, 66, 67, 82, 94, 113, 114,

119, 120, 121, 123, 124, 125, 126, 127, 128, 129, 131, 

132, 141, 143 

SPS-2, 3, 4, 25, 53, 67, 68, 114, 118, 119, 120, 121, 122, 

123, 124, 125, 127, 129, 132, 133, 141 

SPS-3, 4, 29, 45, 48, 63, 65, 68, 79, 86, 87, 90, 91, 92, 99, 

100, 101, 114, 125, 129, 132, 133, 142, 155 

SPS-4, 4, 63, 68, 69, 70, 114, 129, 142, 155 

SPS-5, 4, 66, 67, 68, 83, 115, 119, 120, 122, 125, 127, 129, 

130, 142 

SPS-6, 4, 5, 53, 66, 67, 70, 115, 119, 122, 125, 127, 130, 

142 

SPS-7, 3, 4, 70, 71, 115, 116, 122, 127, 128, 130, 142 

SPS-8, 3, 4, 116, 119, 120, 121, 122, 123, 124, 126, 128, 

130, 131, 132, 133, 143, 145 

SPS-9, 4, 63, 67, 71, 72, 98, 100, 116, 117, 119, 120, 121, 

123, 126, 128, 131, 132, 133, 143 

Standard data release, 107 

Standard Proctor, 94 

STATE_CODE, 13 

Strategic Highway Research Program, 1 

Structured query language, 8 

Subgrade, 92, 93, 94 

Subgrade preparation, 66, 72 

Supplemental sections, 15 

Surface treatments, 90, 91 

T

Table Navigator, 7, 17, 151, 157 

Tensile strength, 88 

Test sections 

Layout, 5 

Locations, 5 

TEST_NO, 80, 82, 83, 85, 86, 87, 88, 89, 90, 91, 92, 93, 

94, 95, 97, 156 

Thermal coefficient of expansion, 88 

Time domain reflectometry, 56 

Traffic data, 73 

Automated vehicle classification, 74 

Axle load distribution, 75 

ESAL, 75, 76, 141, 142, 143 

Historical, 75 

Vehicle classification, 73, 74, 75

Volume counts, 75 

Weigh-in-motion, 74, 76 

Transverse profile 

Data, 47 

Distortion indices, 46 

Measurements, 45, 47 

Truth-in-data, 73

TST_L05A, 101

TST_L05B, 102

U

Unbound base, 66

Unconfined compressive strength, 92, 93 

Undersealing, 67, 70, 142 

V

Vehicle classification, 73, 74, 75

Virtual weather station, 21 

W

Weigh-in-motion, 74, 76 

162