Methods for Maintaining 

Pavement Marking Retroreflectivity

FHWA-SA-22-028 | July 2022
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Technical Report Documentation Form

1. Report No.

FHWA-SA-22-028

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

4. Title and Subtitle

Methods for Maintaining Pavement Marking 

Retroreflectivity

5. Report Date

July 2022

6. Performing Organization Code

7. Author(s)

Adam M. Pike, Cathy Satterfield, Greg Schertz, Joseph 

Cheung, and Kathy W. Falk

8. Performing Organization Report 

No.

9. Performing Organization Name and Address

Texas A&M Transportation Institute

The Texas A&M University System

College Station, TX 77843-3135

10. Work Unit No. (TRAIS)

11. Contract or Grant No.

Contract DTFH61-10-D-000024

12. Sponsoring Agency Name and Address

Office of Safety

Federal Highway Administration

1200 New Jersey Avenue, S.E.

Washington, DC 20590

13. Type of Report and Period 

Covered

14. Sponsoring Agency Code

15. Supplementary Notes

Research performed in cooperation with the U.S. Department of Transportation and the Federal 

Highway Administration. Project Contracting Officer’s Technical Representative: Cathy Satterfield, 

Federal Highway Administration, Office of Safety

16. Abstract

In response to a congressional directive, the Federal Highway Administration established a standard for 

minimum maintained pavement marking retroreflectivity levels that are incorporated in the Manual on 

Uniform Traffic Control Devices (MUTCD). This document, referenced in the MUTCD, describes 

retroreflectivity maintenance methods that, when implemented as intended, provide agencies with a 

flexible means of being in conformance with the standard. These methods were developed specifically 

for longitudinal pavement markings (i.e., center lines, lane lines, and edge lines) although some of the 

methods could also be applicable to other types of markings. Agencies can use the information in this 

report to help determine which retroreflectivity maintenance method or combination of methods best 

suits their needs.

17. Key Words

retroreflectivity, traffic control devices, pavement markings, 

pavement marking maintenance, maintenance methods, 

minimum retroreflectivity, retroreflectometer

18. Distribution Statement

No restrictions. 

19. Security Classif. (this report)

Unclassified

20. Security Classif. (this page)

Unclassified

21. No. of Pages

76

22. Price

N/A

Form DOT F 1700.7 (8-72) Reproduction of completed page authorized
July 2022 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 

in2square inches 645.2 square millimeters mm2

ft2 square feet 0.093 square meters m

2

yd2 square yard 0.836 square meters m

2

ac acres 0.405 hectares ha 

mi2square 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 m

3 

yd3 cubic yards 0.765 cubic meters m

3 

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/in2poundforce 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 

mm2square millimeters 0.0016 square inches in2 

m

2

square meters 10.764 square feet ft2 

m

2

square meters 1.195 square yards yd2 

ha hectares 2.47 acres ac 

km2 square kilometers 0.386 square miles mi2 

VOLUME 

mL milliliters 0.034 fluid ounces fl oz 

L liters 0.264 gallons gal 

m

3 cubic meters 35.314 cubic feet ft3 

m

3 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)

oC Celsius 1.8C+32 Fahrenheit o

F 

ILLUMINATION 

lx lux 0.0929 foot-candles fc 

cd/m2candela/m20.2919 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 th International e System of Units. Appropriate rounding should be made to comply with Section 4 of ASTM E380. 

(Revised March 2003)
July 2022 iii
July 2022 iv

TABLE OF CONTENTS

Chapter 1. Introduction.................................................................................................................1

Purpose...................................................................................................................................... 1

Background............................................................................................................................... 1

Maintaining Pavement Marking Retroreflectivity Performance............................................... 3

Report Organization.................................................................................................................. 4

Chapter 2. Overview of the Methods ...........................................................................................7

Introduction............................................................................................................................... 7

Objectives of the Methods........................................................................................................ 7

Pavement Marking Visibility and Retroreflectivity.................................................................. 9

Acceptable Pavement Marking Retroreflectivity Maintenance Methods............................... 10

Measured Retroreflectivity Method (See Chapter 3)........................................................ 10

Nighttime Visual Inspection Methods.............................................................................. 10

Service Life Based on Historical Data Method (See Chapter 6) ...................................... 11

Service Life Based on Monitored Markings Method (See Chapter 7) ............................. 11

Other Methods .................................................................................................................. 11

Techniques Not Recommended as Pavement Marking Retroreflectivity Maintenance 

Methods................................................................................................................................... 11

Sun-over-the-Shoulder Technique (Not a Recommended Method)................................. 12

Comparison Panel Technique (Not a Recommended Method) ........................................ 12

Lane Line Count Technique (Not a Recommended Method)........................................... 12

Windshield Marking Technique (Not a Recommended Method)..................................... 12

Control Markings Technique (Not a Recommended Method) ......................................... 12

Comparison Light Box (Not a Recommended Method)................................................... 13

Chapter 3. Measured Retroreflectivity Method........................................................................15

Introduction............................................................................................................................. 15

Background............................................................................................................................. 15

Inspector Training................................................................................................................... 16

General Procedures................................................................................................................. 16

Detailed Procedures................................................................................................................ 16

Linking Measurements to Retroreflectivity Levels ................................................................ 18

Advantages.............................................................................................................................. 18

Concerns ................................................................................................................................. 18

Chapter 4. Consistent Parameters Nighttime Visual Inspection Method ..............................19

Introduction............................................................................................................................. 19

Background............................................................................................................................. 19

Inspector Training................................................................................................................... 19

General Procedures................................................................................................................. 20
July 2022 v

Detailed Procedures................................................................................................................ 20

Linking to Maintained Retroreflectivity Levels ..................................................................... 21

Advantages.............................................................................................................................. 21

Concerns ................................................................................................................................. 22

Chapter 5. Calibrated Pavement Markings Nighttime Visual Inspection Method ...............23

Introduction............................................................................................................................. 23

Background............................................................................................................................. 23

Inspector Training................................................................................................................... 24

General Procedures................................................................................................................. 24

Detailed Procedures................................................................................................................ 24

Linking to Retroreflectivity Maintenance Levels................................................................... 26

Advantages.............................................................................................................................. 26

Concerns ................................................................................................................................. 26

Chapter 6. Service Life Based on Historical Data Method ......................................................29

Introduction............................................................................................................................. 29

Procedures............................................................................................................................... 29

Current Practice ...................................................................................................................... 29

Linking Service Life to Retroreflectivity Maintenance Levels .............................................. 30

Advantages.............................................................................................................................. 30

Concerns ................................................................................................................................. 30

Chapter 7. Service Life Based on Monitored Markings Method ............................................31

Introduction............................................................................................................................. 31

Procedures............................................................................................................................... 31

Linking Service Life to Retroreflectivity Maintenance Levels .............................................. 32

Advantages.............................................................................................................................. 32

Concerns ................................................................................................................................. 32

Chapter 8. Frequently Asked Questions....................................................................................33

What Markings Are Subject to the Minimum Maintained Retroreflectivity Levels? ............ 33

Is a Retroreflectometer Required to Use the Pavement Marking Retroreflectivity 

Maintenance Methods Described in This Report?.................................................................. 33

Is an Inventory Necessary? ..................................................................................................... 33

Does an Inspector Need to Be at Least 60 Years Old? ........................................................... 33

Can I Use Any Vehicle for the Nighttime Inspection Methods? ............................................ 33

Are Annual Inspections Frequent Enough? ............................................................................ 34

Is Documentation of My Inspections Required? .................................................................... 34

What If I Cannot Restore All Markings According to the Replacement Schedule? .............. 34

Am I Allowed to Use Resources or Take Actions outside My Written or Documented 

Method and Still Be Considered in Compliance?................................................................... 34
July 2022 vi

References.....................................................................................................................................35

Appendix A: Final Rule—Pavement Marking Retroreflectivity MUTCD Text....................37

Appendix B: Method Development............................................................................................39

Getting Started ........................................................................................................................ 39

Maintenance Methods............................................................................................................. 39

Deciding Which Roads and Markings to Include in the Method............................................ 39

Method Development: Measured Retroreflectivity ................................................................ 41

Method Definition............................................................................................................. 41

Method Needs................................................................................................................... 42

Method Implementation.................................................................................................... 42

Examples........................................................................................................................... 44

Method Development: Consistent Parameters Nighttime Visual Inspection ......................... 47

Method Definition............................................................................................................. 47

Method Needs................................................................................................................... 47

Method Implementation.................................................................................................... 47

Examples........................................................................................................................... 49

Method Development: Calibrated Pavement Markings Nighttime Visual Inspection ........... 52

Method Definition............................................................................................................. 52

Method Needs................................................................................................................... 52

Method Implementation.................................................................................................... 52

Examples........................................................................................................................... 55

Method Development: Service Life Based on Historical Data............................................... 59

Method Definition............................................................................................................. 59

Method Needs................................................................................................................... 59

Method Implementation.................................................................................................... 59

Examples........................................................................................................................... 60

Method Development: Service Life Based on Monitored Markings...................................... 64

Method Definition............................................................................................................. 64

Method Needs................................................................................................................... 64

Method Implementation.................................................................................................... 64

Examples........................................................................................................................... 66
July 2022 vii

LIST OF FIGURES

Figure 1. Text. MUTCD maintaining minimum pavement marking retroreflectivity.................... 2

Figure 2. Diagram. 30-meter geometry......................................................................................... 15

Figure 3. Photo. Measuring retroreflectivity with a handheld instrument.................................... 17

Figure 4. Photo. Typical mobile pavement marking retroreflectivity measurement 

instrument....................................................................................................................... 17

Figure 5. Text. Headlamp aiming procedure.(22)........................................................................... 21

Figure B1. Diagram. Roadways to be included in the method. .................................................... 45

Figure B2. Diagram. Roadways included in method and evaluated this year. ............................. 45

Figure B3. Diagram. Example of monitored markings map......................................................... 66

LIST OF TABLES

Table 1. Range of pavement marking service life estimates.(26)................................................... 29

Table B1. Maintenance method information and data needs........................................................ 41

Table B2. Spreadsheet example of roadway database for measured retroreflectivity.................. 46

Table B3. Example inspection data collection sheet for consistent parameters nighttime 

visual inspection. ............................................................................................................ 50

Table B4. Spreadsheet example of roadway database for consistent parameters nighttime 

visual inspection. ............................................................................................................ 51

Table B5. Example survey data collection sheet for calibrated pavement markings 

nighttime visual inspection............................................................................................. 57

Table B6. Spreadsheet example of roadway database for calibrated pavement markings 

nighttime visual inspection............................................................................................. 58

Table B7. Hypothetical example of expected pavement marking service life (Do not use 

these values—example only).......................................................................................... 62

Table B8. Spreadsheet example of roadway database for service life based on historical 

data (hypothetical data). ................................................................................................. 63

Table B9. Spreadsheet example of roadway database for service life based on monitored 

markings. ........................................................................................................................ 67
July 2022 viii

ABBREVIATIONS AND ACRONYMS

AASHTO American Association of State Highway and Transportation Officials

AASHTO Guide American Association of State Highway and Transportation Officials 

Roadway Lighting Design Guide, 7th Edition

ADT average daily traffic

ANSI American National Standards Institute 

CFR Code of Federal Regulations

FAQ frequently asked question

FHWA Federal Highway Administration

GIS geographic information systems

IESNA Illuminating Engineering Society of North American

LTAP Local Technical Assistance Program

MUTCD Manual on Uniform Traffic Control Devices

RRPM raised retroreflective pavement marker
July 2022 1

CHAPTER 1. INTRODUCTION 

Purpose 

On August 5, 2022, the Federal Highway Administration (FHWA) published a final rule that 

incorporated a standard for maintaining minimum retroreflectivity levels for pavement markings 

into Section 3A.03 of the Manual on Uniform Traffic Control Devices (MUTCD) (see figure 1 

and Appendix A). This document, referenced in the MUTCD, describes retroreflectivity 

maintenance methods that, when implemented as intended, provide agencies with a flexible 

means of conforming to the standard. This document includes a number of potential methods 

because different agencies have varying levels of staffing, equipment, budgets, road systems, and 

expertise. 

It is not the purpose of this report to provide information on the initial installation of markings 

and does not address initial retroreflectivity levels. The report provides information about 

methods to help agencies ensure pavement markings are replaced before they reach the end of 

their useful service life and no longer meet nighttime driving needs. This report also includes 

background information on pavement marking retroreflectivity. 

Background 

Reducing transportation-related fatalities and serious injuries across the transportation system is 

the first of four goals listed in FHWA’s Strategic Plan.(1)In 2019, 36,096 people died in motor 

vehicle traffic crashes in the United States.(2) While only a quarter of travel occurs at night,(3)

about one-half of traffic fatalities occur during nighttime hours.(4) This translates to a nighttime 

fatality rate that is approximately three times greater than that of daytime. There are many 

reasons for this disparity, such as reduced visibility, impaired driving, and fatigue. One way to 

address the visibility of roadway delineation is to evaluate the retroreflectivity of in-service 

pavement markings and replace pavement markings that are no longer performing at their 

intended level by implementing effective retroreflectivity maintenance methods. 

Retroreflection (more commonly referred to as retroreflectivity) is a special type of reflection 

where light reflecting off a surface is redirected back toward the source. For the case of 

pavement markings, light from vehicle headlamps is reflected from the markings back toward the 

vehicle, making the markings appear brighter to the driver than they would be otherwise. 

Pavement marking retroreflectivity can be measured and is a key indicator of the nighttime 

visibility of pavement markings. Maintaining pavement marking retroreflectivity to a level that 

meets nighttime driver needs is consistent with FHWA’s goal of improving safety on the 

Nation’s streets and highways. Many safety and operational strategies depend on pavement 

marking visibility that meets the needs of drivers. Furthermore, recent research shows reduction 

in both daylight and nighttime crashes with the presence of markings and increased probability 

of crashes for very low retroreflectivity values, thereby indicating there are nighttime safety 

benefits of maintaining longitudinal pavement marking retroreflectivity.(5–8)
July 2022 2

Figure 1. Text. MUTCD maintaining minimum pavement marking retroreflectivity.

Section 3A.03 Maintaining Minimum Retroreflectivity

Standard:

01 Except as provided in Paragraph 5, a method designed to maintain retroreflectivity at or 

above 50 mcd/m2/lx under dry conditions shall be used for longitudinal markings on roadways with 

speed limits of 35 mph or greater. 

Guidance:

02 Except as provided in Paragraph 5, a method designed to maintain retroreflectivity at or above 

100 mcd/m2/lx under dry conditions should be used for longitudinal markings on roadways with speed 

limits of 70 mph or greater.

03 The method used to maintain retroreflectivity should be one or more of those described in 

“Methods for Maintaining Pavement Marking Retroreflectivity” (see Section 1A.11) or developed from an 

engineering study based on the values in Paragraphs 1 and 2.

Support:

04 Retroreflectivity levels for pavement markings are measured with an entrance angle of 88.76 degrees 

and an observation angle of 1.05 degrees. This geometry is also referred to as 30-meter geometry. The units 

of pavement marking retroreflectivity are reported in mcd/m2/lx, which means millicandelas per square meter 

per lux. 

Option:

05 The following markings may be excluded from the provisions established in Paragraphs 1 and 2: 

A. Markings where ambient illumination assures that the markings are adequately visible;

B. Markings on streets or highways that have an ADT of less than 6,000 vehicles per day; 

C. Dotted extension lines that extend a longitudinal line through an intersection, major driveway, or 

interchange area (see Section 3B.08);

D. Curb markings;

E. Parking space markings; and

F. Shared-use path markings.

Support:

06 The provisions of this section do not apply to non-longitudinal pavement markings including, but 

not limited to, the following:

A. Transverse markings;

B. Word, symbol, and arrow markings;

C. Crosswalk markings; and 

D. Chevron, diagonal, and crosshatch markings.

07 Special circumstances will periodically cause pavement marking retroreflectivity to be below the 

minimum levels. These circumstances include, but are not limited to, the following:

A. Isolated locations of abnormal degradation; 

B. Periods preceding imminent resurfacing or reconstruction;

C. Unanticipated events such as equipment breakdowns, material shortages, and contracting 

problems; and

D. Loss of retroreflectivity resulting from snow maintenance operations. 

When such circumstances occur, compliance with Paragraphs 1 and 2 is still considered to be achieved if a 

reasonable course of action is taken to resume maintenance of minimum retroreflectivity in a timely 

manner according to the maintaining agency’s method(s), policies, and procedures.
July 2022 3

Improvements in pavement marking visibility will also support FHWA’s efforts to be responsive 

to the needs of older drivers whose visual capabilities are declining. This is important because 

the number of older drivers is expected to increase significantly in the coming years. In 2019, 

54.1 million drivers in the United States were at least 65 years old.(9) The U.S. Department of 

Transportation estimates that there will be more than 72 million licensed drivers 65 years and 

older by 2030.

(10)

In addition, there is an increased interest in pavement marking visibility for

automated vehicle guidance.

When pavement markings were first used about 100 years ago, they were hand-painted along the 

center lines of dangerous curves and were not retroreflective. Since then, there have been many 

improvements in pavement markings, such as adding optics (typically glass beads) to provide 

nighttime visibility. Now pavement markings provide more safety benefits than ever. Recent 

studies, as well as those more than a half-century old, have continuously shown that adding edge 

lines to rural two-lane highways can reduce crashes and fatalities. More recent research findings 

demonstrate that benefits can be achieved using pavement marking edge lines with pavement 

widths as narrow as 18 feet and traffic volumes as low as 400 vehicles per day.(11) Other recent

pavement marking research findings are included in a 2015 FHWA synthesis including topics

such as the effects of pavement marking width and retroreflectivity.

(12)

The opening statements of the MUTCD define the purpose of traffic control devices and the 

principles for their use. Traffic control devices, including pavement markings, are meant to 

promote highway safety and efficiency by providing for the orderly movement of all road 

users.(13)(The MUTCD is incorporated by reference in 23 CFR 655.601 and is available on

FHWA’s website at http://mutcd.fhwa.dot.gov.) 

To ensure consistent application, the MUTCD describes the characteristics of and warranting 

criteria for pavement markings.(13) The Code of Federal Regulations (CFR) at 23 CFR 655

defines pavement marking colors. The MUTCD web page http://mutcd.fhwa.dot.gov/knocolorspec.htm also references pavement marking colors. The importance of pavement marking 

retroreflectivity has been recognized in the current MUTCD, which states, “Markings that must 

be visible at night shall be retroreflective unless ambient illumination assures that the markings 

are adequately visible. All markings on Interstate highways shall be retroreflective.”(13)

Maintaining Pavement Marking Retroreflectivity Performance 

The most common way to specify retroreflectivity for markings is to use the international 

standard of 30-meter geometry, expressed in units of millicandelas per square meter per lux 

(mcd/m2/lx). As the name indicates, this geometry represents the viewing scenario of a pavement 

marking 30 meters in front of a vehicle (specifically, a passenger sedan although vehicle size is 

not a critically sensitive parameter in nighttime pavement marking performance). Agencies often 

specify pavement marking retroreflectivity criteria for newly installed markings and less often 

for in-service pavement marking performance. 

Generally, maintaining the daytime performance of pavement markings (i.e., presence and color) 

is less of an issue for agencies than maintaining nighttime performance (retroreflectivity). The 

nighttime performance of pavement markings can be more difficult to maintain for a variety of 

reasons, including wear due to traffic, roadway debris, and especially snowplowing activities. 
July 2022 4

Pavement markings generally use small glass beads to retroreflect light back toward the vehicle. 

The glass beads are applied to a variety of binder materials (e.g., water-based paints, solventbased paints, thermoplastic, and epoxy) so that they are partially embedded but also exposed. If 

the beads get damaged or knocked out of the binder material, the retroreflectivity will degrade 

even though the marking may still be present. Generally, the retroreflectivity of pavement 

markings will fade faster than the presence of the marking, making the nighttime performance 

more difficult to maintain than the daytime performance. Another factor that comes into play 

with markings is that they are installed in varying field conditions (e.g., different contractors 

using different equipment applying the markings at different speeds during a variety of weather 

conditions), making their initial performance variable. Studies have also shown that it is difficult 

to accurately predict pavement marking retroreflectivity degradation, even if the initial 

retroreflectivity level is known. 

As pavement markings degrade and become less retroreflective, their effectiveness for 

communicating the intended travel path and roadway alignment to nighttime road users 

diminishes. If left unattended, pavement marking retroreflectivity can diminish to the point that 

the markings cannot be seen in time for nighttime drivers to properly react. Thus, to maintain 

nighttime effectiveness, pavement markings must be replaced before they reach the end of their 

useful retroreflective life. 

This report focuses on those methods that are most appropriate for monitoring pavement marking 

retroreflectivity to determine when they need to be replaced. Other techniques briefly described 

in chapter 2 may be appropriate for other purposes but were considered inadequate for the 

purposes of maintaining pavement marking retroreflectivity in accordance with the standard in 

the MUTCD. 

Report Organization 

This report outlines maintenance methods intended to provide agencies with a flexible means of 

maintaining conformance with the MUTCD standard for minimum retroreflectivity of pavement 

markings. Although mainly descriptive of the evaluation and monitoring processes, all methods 

described in chapters 3 through 7 are helpful in the decision process for replacing or restriping 

longitudinal markings.

Chapter 2 covers the objectives of the pavement marking retroreflectivity maintenance methods. 

The maintenance methods are introduced and defined. In addition, other inspection techniques 

that are not recommended to be used as maintenance methods are discussed.

Chapter 3 includes a description of the measured retroreflectivity method. This chapter includes 

information related to sampling and averaging pavement marking retroreflectivity with handheld

and mobile equipment. This chapter identifies the link between the measurements and the 

MUTCD retroreflectivity levels. This chapter also identifies the advantages and potential 

concerns of this method.

Chapter 4 describes the consistent parameters nighttime visual inspection method. Background 

information on this method, instructions for conducting this inspection method, and how this 
July 2022 5

method links to specific retroreflectivity levels are described. Advantages and potential concerns

are also included. 

Chapter 5 describes the calibrated pavement markings nighttime visual inspection method. 

Background information, a description of the general procedures, details of applying this 

inspection method, and how this links to specific retroreflectivity levels are included. This 

chapter also identifies the advantages and potential concerns of this method. 

Chapter 6 describes the service life based on historical data method. Procedures for conducting 

this method, current practices, and linking the service life to the MUTCD retroreflectivity levels 

are included. Advantages and potential concerns are also included. 

Chapter 7 describes the service life based on monitored markings method. Procedures for 

conducting this method and linking the service life to the MUTCD retroreflectivity levels are 

included. This chapter also identifies the advantages and potential concerns of this method.

Chapter 8 includes a list of questions and answers to support the pavement marking 

retroreflectivity methods. 

July 2022 7

CHAPTER 2. OVERVIEW OF THE METHODS

Introduction

Traditionally, agencies have implemented different methods to ensure their pavement markings 

are maintained to meet drivers’ needs in relation to local conditions, needs, and priorities. These 

maintenance methods are understood to incorporate both the process to determine when to remark roadways and a schedule to replace the markings. The methods in this report do not, 

however, cover the actual installation process, which varies significantly depending on the 

materials, specifications, and equipment used. This chapter introduces the objectives in 

implementing a retroreflectivity maintenance method and then briefly describes a number of 

potential methods that FHWA recommends would achieve the objectives. Each method is then 

described in detail in chapters 3 through 7. This chapter also describes other techniques that were 

considered and determined not appropriate to achieve the objectives.

The maintenance management process begins with agency policies and practices regarding the 

use of pavement marking materials. Agency policies have often been driven by the costs of the 

various marking materials and weighed against their durability. Agencies in the north that have 

consistent snow removal needs experience considerably different marking durability from 

agencies in the south that do not have these needs.

Once new pavement markings have been installed, there is a need to determine when the 

markings will reach the end of their useful life so they are replaced before they no longer provide 

the intended delineation in both daytime and nighttime conditions. By and large, the most 

common method used to trigger the replacement of pavement markings has been visual 

inspection. However, other retroreflectivity maintenance methods have also been tested and 

implemented, including measuring retroreflectivity and re-applying markings based on 

anticipated service life. 

The MUTCD recommends agencies to use a method, which may include a single method or 

combination of methods described in this report, designed to maintain retroreflectivity at or 

above the minimum levels specified.

Objectives of the Methods

The intent of these maintenance methods is to provide a systematic means for agencies to ensure 

their longitudinal pavement marking retroreflectivity is continually at or above minimum 

maintained retroreflectivity requirements as established in the MUTCD. Use of the method

implies not only determining when pavement markings need to be refreshed, but also scheduling 

the replacement of deficient markings in a timely manner. While the use of one or more of these 

methods will not guarantee that every inch of pavement marking will meet or exceed the

MUTCD minimum levels at every point in time, these methods will help ensure that longitudinal 

pavement markings are typically replaced before they become inadequate in terms of their 

nighttime visibility. 

Having a method in place to maintain retroreflectivity can help agencies prioritize how to spend 

limited resources, maximize the life of pavement markings, and ultimately contribute to 
July 2022 8

improved safety for the motoring public. While the use of a particular method does not guarantee 

that all markings will be visible at all times, such as during snow and rain events, the overall 

safety of the agency’s roadway network will be improved by having such a maintenance method 

in place.

Regardless of how an agency chooses to ensure that pavement marking retroreflectivity is 

properly maintained, documentation of the process can be beneficial for many reasons. Written 

procedures help ensure that agency personnel properly follow the selected method, and 

maintenance records provide the agency with a systematic process for scheduling replacements 

and justification for the allocation of limited resources. For example, measurements of pavement 

marking retroreflectivity might show that certain markings are near or below the MUTCD levels 

earlier than expected based on service life predictions. The records provide documentation that 

an appropriate maintenance method was followed, and permit the agency to assess and revise the 

expected service life for a given type or group of markings, if necessary. If an agency has a 

method in place to manage or assess its markings and establishes a reasonable schedule for 

replacing markings as needed, the agency is better able to justify that it has met its performance 

goals. It is also quite possible that agencies will realize that they can achieve more life from their 

markings than previously expected. Documentation of the pavement marking retroreflectivity 

maintenance process can include a variety of information and levels of detail. The form and 

extent of documentation are up to the discretion of the individual agency. However, some items 

an agency might consider are described as follows:

• To prioritize and manage their programs, agencies may want to include a feature in their 

pavement marking retroreflectivity maintenance method that can adapt to changes in 

roadway volume and speed. 

• Similarly, the maintenance management program could be flexible so that changes to 

pavement marking practices (i.e., binder material selection and retroreflective optics 

selection) can be easily accommodated. 

• Because ambient illumination has an impact on the visibility of pavement markings, 

agencies may choose to place a lower priority on roadways where ambient illumination 

assures that the markings are adequately visible. A report from Alaska shows that when 

continuous lighting is used along stretches of highway with low pavement marking 

retroreflectivity, the pavement marking visibility can remain adequate.(14) On its lighted 

sections of roadway, Alaska strives to maintain retroreflectivity, but knowing that 

presence, combined with lighting, provides adequate nighttime visibility, Alaska is free to

allocate its resources to other priorities. This does not apply to intersection or safety 

lighting, where isolated areas of a roadway are lighted—those areas still need to be 

included in the agency’s maintenance method.

In the United States, two primary documents describe roadway lighting criteria: the 

Recommended Practice: Lighting Roadway and Parking Facilities (ANSI/IES RP-8-21) and the 

American Association of State Highway and Transportation Officials (AASHTO) Roadway 

Lighting Design Guide, 7th Edition (known as the AASHTO Guide).

(15, 16) The Recommended

Practice for Lighting Roadway and Parking Facilities, published by the Illuminating 

Engineering Society (IES), is commonly used by public agencies as the basis for establishing the 

appropriate lighting level design values for roadway lighting. This publication has been approved 

by the American National Standards Institute (ANSI) and is commonly referred to as RP-8. The 
July 2022 9

RP-8 lighting design criteria parallels the lighting criteria found in the AASHTO Guide, except

for the general land-use parameter. The RP-8 criteria are based on an assessment of the roadway 

classification and pedestrian conflict area classification rather than the general land-use 

classification found in the AASHTO Guide.

A roadway or corridor may be planned for rehabilitation or resurfacing but have existing 

pavement markings with retroreflectivity approaching minimum levels. In such cases, a decision 

needs to be made about restriping the roadway, given that it will soon be resurfaced. In these 

cases, an agency could choose to set a maximum time frame between identification of potential

inadequate pavement marking retroreflectivity and resurfacing. If more time than the maximum 

time frame is expected, an agency could decide to install a low-cost temporary pavement 

marking (e.g., conventional waterborne paint and AASHTO M247 Type I beads), issue a

restriping contract, or include a provision within the resurfacing contract that conveys the 

maintenance of the markings, according to the MUTCD standard, to the contractor once the 

project is let for construction.

Resources will change over time, and unexpected events will occur. It will be important to 

establish documentation and make revisions as necessary. When extraordinary events occur,

such as resource shortages or circumstances outside the control of the agency, documentation can 

be advantageous for justification of not meeting MUTCD levels. Repetitive instances of failure 

to maintain retroreflectivity may indicate a need to change resources or revise the documented 

method. Examples to address such occurrences could be:

• Revisions to standard operating procedures to accelerate replacement schedules in highwear areas.

• Inclusion of new resources in lieu of or in combination with agency resources.

• Characterization of procurement rule changes that impact material deliveries.

Pavement Marking Visibility and Retroreflectivity

The ability to see a pavement marking at night is not solely a function of the retroreflective 

characteristics of the pavement marking, but is also dependent on several other factors such as: 

• The amount and pattern of light produced by a vehicle’s headlights.

• The amount of light reaching the pavement marking.

• The visual complexity of the scene (e.g., rural or urban).

• The weather (e.g., clear, rainy, or foggy).

• The visual capabilities of the observer.

A key factor in determining the visibility of a pavement marking is the contrast between the 

marking and the adjacent pavement surfaces. During daylight hours, ambient light provides 

pavement marking visibility by striking the marking surface. The reflected light scatters in all 

directions, but some of it reaches the driver’s eyes. However, in dark environments (without 

roadway lighting), vehicle headlamps produce most of the light striking a pavement surface, and 

therefore the retroreflective properties of the pavement marking govern the amount of light that 

reaches the driver’s eyes. While optics such as glass beads primarily provide the retroreflective 

performance of pavement markings, other factors also contribute to retroreflective performance. 
July 2022 10

These include the properties of the binder material (e.g., color, pigment type and amount, type, 

and thickness), pavement surface roughness, and amount of debris and dirt on the marking. 

Acceptable Pavement Marking Retroreflectivity Maintenance Methods

The FHWA hosted a series of workshops around the country to solicit city, county, and State 

transportation agency input regarding issues about implementing a national standard on 

minimum pavement marking retroreflectivity levels.

(17) One of the most consistent comments 

was that a one-size-fits-all solution would not be practical, and that FHWA needed to provide 

flexibility in terms of meeting the minimum retroreflectivity levels. Therefore, this report

includes several potential methods that agencies can choose from to maintain the retroreflectivity 

of their markings. Although mainly descriptive of the evaluation and monitoring processes, all 

methods listed here and described in detail in chapters 3 through 7 are helpful in the decision 

process of replacing or restriping longitudinal markings. Appendix B provides examples of how 

an agency might implement each of the maintenance methods.

Measured Retroreflectivity Method (See Chapter 3)

In this method, pavement marking retroreflectivity is measured and directly compared to the 

MUTCD minimum levels. The retroreflectivity measurements can be made with either handheld

or mobile instruments using the standard 30-meter geometry. Inspectors must follow the 

instructions provided by the manufacturer to obtain reliable retroreflectivity readings, including 

periodically calibrating the equipment. Chapter 3 has more information about this method. 

Nighttime Visual Inspection Methods

This report describes two types of nighttime visual inspections that can be implemented to 

maintain pavement marking retroreflectivity. Both methods are meant to be conducted during 

dry nighttime conditions. These two methods have common elements such as:

• The use of low-beam headlamp illumination.

• Inspections conducted at prevailing nighttime speeds.

• The use of trained inspectors.

• The dependence on subjective evaluations. 

Consistent Parameters Nighttime Visual Inspection Method (See Chapter 4)

The consistent parameters inspection method is based on factors similar to those that were used 

in the research to develop a set of recommended minimum retroreflectivity levels. This method 

involves a nighttime review at highway speeds with low-beam headlamps by an inspector who is

aged 60 years or older. The trained inspector judges the adequacy of the markings to meet his or 

her nighttime driving needs. Chapter 4 has more information about this method.

Calibrated Pavement Markings Nighttime Visual Inspection Method (See Chapter 5)

This method uses a trained inspector to view calibrated pavement markings at night prior to 

conducting a nighttime visual inspection. Calibrated pavement markings have known 

retroreflectivity at or above MUTCD levels. These pavement markings are set up where the 
July 2022 11

inspector can view them in a manner similar to the conditions of the nighttime visual inspections. 

The markings can be in a maintenance yard, along a service road or other such facility, or on a 

road open to public travel. The inspector uses the visual appearance of the calibrated pavement 

markings to establish evaluation thresholds for that night’s inspection activities. Chapter 5 has 

more information about this method.

Service Life Based on Historical Data Method (See Chapter 6)

Using this method, an agency documents pavement marking installation dates and, using 

historical data or research results, establishes a schedule for replacing the markings. The 

schedule to replace the markings is designed to prevent the pavement marking retroreflectivity 

from falling below the MUTCD minimum levels. Pavement marking replacement schedules can 

be set for similar markings in similar conditions (considering factors such as pavement marking 

type, retroreflective optics, pavement type, pavement condition, and traffic volumes). Chapter 6 

has more information about this method.

Service Life Based on Monitored Markings Method (See Chapter 7)

Using this method, an agency documents pavement marking installation dates and periodically 

monitors the retroreflectivity of a subset of the markings as a way to track their durability. The 

monitored markings represent a larger group of similar markings in similar conditions. When the 

monitored markings degrade and approach the MUTCD minimum levels, the entire group of 

markings (both monitored and the larger group they represent) are restriped. This is an 

alternative method for agencies that want to use a service life type of method but do not have 

historical data or specific research supporting service life estimates for their region and specific 

conditions. Chapter 7 has more information about this method.

Other Methods 

An effective approach may be to combine one or more of these methods or to develop other 

methods based on engineering studies. If an agency develops a different method, however, it is 

important that the method be based on an engineering study and tied to the MUTCD minimum 

levels. An example of a combined method is performing one of the visual assessment methods to 

determine the quality of the markings: markings deemed as failing are replaced, markings 

deemed as adequate are left alone, and markings deemed as marginal are evaluated with a 

measured retroreflectivity method.

Techniques Not Recommended as Pavement Marking Retroreflectivity 

Maintenance Methods 

FHWA identified several other pavement marking assessment techniques and considered but 

ultimately did not include these in the recommended methods, either because they could not be 

tied to a specific retroreflectivity level or due to other concerns. These techniques are described 

as follows. Future technologies and research may demonstrate that these techniques, or other 

innovative techniques, can be successfully used to maintain pavement marking retroreflectivity

levels above the minimum levels in the MUTCD.
July 2022 12

Sun-over-the-Shoulder Technique (Not a Recommended Method)

The sun-over-the-shoulder check is an evaluation of pavement marking retroreflectivity normally 

used to assess the general quality of freshly installed pavement markings. This quality control 

check is conducted during daylight hours. Contractors and agencies use this technique to check 

bead coverage during installation; it does not ensure specific retroreflectivity levels. The sunover-the-shoulder technique is not considered a suitable pavement marking maintenance method 

to determine if and when longitudinal pavement markings have reached the end of their useful 

service life because it does not have a capability to tie the observation to a level of 

retroreflectivity at night.

Comparison Panel Technique (Not a Recommended Method)

The comparison panel technique involves placing a comparison panel with a known 

retroreflectivity level at or above a specific retroreflectivity level next to an in-service pavement 

marking. An inspector views the combination at a specified distance (e.g., 30 meters). If the 

comparison panel appears brighter than the pavement marking, the marking needs to be replaced. 

This technique needs to be conducted at night and with traffic control (for safety reasons). While 

this method is acceptable for the airfield markings for which it was developed, workshop 

participants deemed it unsafe for roadways because it entails too much risk for the inspectors. 

Lane Line Count Technique (Not a Recommended Method)

To use this technique, inspectors count the number of lane lines visible from the driver’s seat of a 

static test vehicle. This count of visible lane lines is multiplied by the lane line length and 

spacing to calculate visibility distances. While it is possible to tie a retroreflectivity level to a 

visibility distance, the need to have the inspection vehicle in a static position places the 

inspectors at risk. It is not feasible to accurately count the lane lines from a moving vehicle. In 

addition, this technique would not be possible on roadway sections without broken lines (e.g. 

two-lane roads with no passing allowed).

Windshield Marking Technique (Not a Recommended Method)

With this technique, a mark (using tape) is placed on the windshield at the line of sight for the 

inspector. This mark coincides with a visibility distance derived from a preview time of 

2.2 seconds and the posted or prevailing nighttime speed of the roadway. The inspector then 

drives the roads at appropriate speed (the mark would need to be adjusted for speed) and 

disqualifies any segments where the pavement marking cannot be seen at the appropriate 

distance. This technique is not directly tied to specific pavement marking retroreflectivity levels. 

In addition, there is concern that minor changes in the driver position (e.g., slouching) would 

affect the accuracy of this system. Future research may determine an effective method using this 

technique. 

Control Markings Technique (Not a Recommended Method)

A maintenance method described in the MUTCD for maintaining traffic sign retroreflectivity is 

called the control sign method and involves monitoring a subsample of traffic signs to determine 

their service life based on minimum sign retroreflectivity levels. As the control signs near the 
July 2022 13

end of their retroreflective life, they are scheduled for replacement along with the other inservice signs of the same age and materials. The control signs can be signs in a maintenance yard 

or in-service signs. 

For pavement markings, this method is called the service life based on monitored markings

method and is different in that the monitored markings must be in-service markings because the 

degradation of markings is so dependent on the wear they experience from traffic. Chapter 7 has 

more information about the service life based on monitored markings method. 

Comparison Light Box (Not a Recommended Method)

A comparison light box is a handheld device that performs a daytime check of pavement 

marking retroreflectivity. The device is similar in size to a pavement marking retroreflectometer 

but is significantly less expensive. The device is composed of a box with a mirror and a light to 

show the appropriate geometry as the inspector looks directly down into the box. The image that 

the inspector sees is a side-by-side comparison of the in-service marking and a calibrated 

marking (placed within the device) that has a specific retroreflectivity level (at or above MUTCD 

levels). While this device provides a side-by-side comparison, it is not appropriate to use a 

comparison light box in a similar manner to a handheld pavement marking retroreflectometer. 

Both devices are used by placing them on the pavement marking to be inspected, but the 

retroreflectometer can be operated with a trigger pull and does not need the inspector to glance 

away from the roadway. With the comparison light box, on the other hand, the inspector needs to 

look down into the device, focus, and then make a decision, demanding the inspector look away 

from the roadway for a significant period. The comparison light box technique works, if it is 

used in a safe location such as with the appropriate traffic control. However, the handheld 

retroreflectometer provides a more objective measure of retroreflectivity and reduces user risk by 

allowing the user to scan traffic. The handheld retroreflectometer is more expensive but is

preferred over the comparison light box.

July 2022 15

CHAPTER 3. MEASURED RETROREFLECTIVITY METHOD

Introduction

In general, pavement marking retroreflectivity can be measured in the field in two ways: with 

handheld instruments or with mobile instruments. Handheld instruments must be placed on the 

pavement marking. Mobile instruments are attached to a vehicle and measure the pavement 

marking retroreflectivity as the instrumented vehicle is driven at typical roadway speeds. Both 

types of instruments provide objective retroreflectivity values that can be used in direct 

comparison to the MUTCD levels. The measurement method as an exclusive process to maintain 

pavement marking retroreflectivity has not historically appealed to agencies, as will be discussed 

in this chapter. However, when combined with a visual or service life method, the measured 

pavement marking retroreflectivity method adds an element of objectivity to the overall 

maintenance program. This combination of methods may enable agencies to more efficiently use 

their maintenance budgets. 

Background

Pavement marking retroreflectivity levels are specified in the MUTCD at 30-meter geometry. 

Essentially, retroreflective measurements made under 30-meter geometry simulate the 

retroreflective performance of the pavement marking at a distance 30 meters in front of the 

vehicle (using entrance and observation angles of 88.76 and 1.05 degrees, respectively)

(figure 2).

Figure 2. Diagram. 30-meter geometry.

For handheld retroreflectometer measurements, ASTM International has developed a 

standardized practice, ASTM D7585/D7585M, Standard Practice for Evaluating Retroreflective 

Pavement Markings Using Portable Hand-Operated Instruments.

(18) This standardized practice 

provides guidance on topics such as how many readings are needed. Currently, there is no 

national standard for mobile retroreflectometer measurements. 

Several handheld retroreflectometers that can be used to measure pavement marking 

retroreflectivity are commercially available. While both the handheld measurement instruments 

and the mobile measurement instruments provide similar results related to measurement bias, 

repeatability, and reproducibility,(19) using handheld instruments can be time consuming if many 
July 2022 16

roadways with miles of pavement markings are to be sampled. Mobile pavement marking 

retroreflectivity measurement instruments offer flexibility and efficiency for the measurement 

process. However, mobile measurement instruments necessitate a relatively high level of capital 

investment for those agencies interested in purchasing their own. Alternatively, some companies 

specialize in pavement marking measuring services using both handheld and mobile 

measurement instruments. 

Inspector Training

The company selling the handheld or mobile retroreflectivity measurement instrument is best 

suited for providing training for proper use of the device. Specific calibration procedures and 

maintenance schedules for the equipment are important to follow in order to obtain accurate and 

repeatable measurements. 

General Procedures

Measuring retroreflectivity using a handheld instrument is to be performed in safe conditions 

with appropriate traffic control. Measuring retroreflectivity using a mobile instrument provides 

relief from the need for traffic control. Using either type of instrument, the measurements must 

be made under dry conditions (pavement marking retroreflectivity can be measured under wet 

recovery and wet continuous conditions, but the minimum maintenance levels in the MUTCD 

pertain only to dry conditions). It is important to maintain a record of the measurements, when 

they were made, and other related information as deemed appropriate. If the measured 

retroreflectivity value approaches or is less than the MUTCD minimum level, the markings are 

scheduled for replacement.

Detailed Procedures

The basic procedure using a handheld retroreflectometer is to:

1. Calibrate the retroreflectometer each day before beginning measurements.

2. Select the segment of marking to be measured.

3. Take 16 or more measurements at regular intervals on that segment, ensuring the 

retroreflectometer is facing the direction of traffic appropriate to that line. If measuring a 

single center line, take measurements in both directions. 

4. Document the individual readings and the average for the segment.

5. Move to the next line (e.g., if measuring center and edge lines) or the next segment.

6. Repeat steps 2 through 5.

See ASTM D7585/D7585M(18)for further details.

The basic procedure for mobile measurements is similar to that for handheld measurements. 

Differences include no need for traffic control, additional efforts to verify accurate calibration, 

and the ability to collect larger amounts of data in a shorter time fame.

Examples of handheld and mobile pavement marking retroreflectometers are shown in figure 3

and figure 4, respectively. Handheld retroreflectometers are much less expensive than mobile 

units, are much easier to use, and require less training. However, handheld units are inconvenient 
July 2022 17

when a large number of measurements are needed or when measuring on roads with high traffic 

volumes. Safety issues are also related to the use of handheld units because workers are often 

exposed to traffic while measuring the retroreflectivity of a marking. Taking handheld

measurements may also involve lane closures, increasing delay to motorists. 

Figure 3. Photo. Measuring retroreflectivity with a handheld instrument.

Figure 4. Photo. Typical mobile pavement marking retroreflectivity measurement 

instrument.
July 2022 18

Mobile units, on the other hand, are significantly more expensive than handheld units and require 

a significant amount of training and maintenance. However, mobile retroreflectometers produce 

a very large number of measurements (typically one measurement every inch) and allow for 

measurements to be taken at highway speeds without exposing personnel to traffic or lane 

closures. Some transportation agencies own mobile retroreflectometers, while others hire 

qualified contractors to perform mobile retroreflectivity measurements. 

Linking Measurements to Retroreflectivity Levels

This method uses measured retroreflectivity as the basis for the decision of whether pavement 

markings meet the MUTCD minimum levels of retroreflectivity. The measured retroreflectivity 

values are compared to the minimum retroreflectivity levels specified in the MUTCD. Where 

measurements indicate pavement marking retroreflectivity is at or near the applicable level, the 

agency is expected to schedule marking replacement for these segments of roadway. This 

method provides the most direct comparison of in-service pavement marking retroreflectivity 

relative to the minimum maintained retroreflectivity levels.

Advantages

Retroreflectivity measurements can be made during the day. Measurements provide the most 

direct and objective means of monitoring pavement marking retroreflectivity levels.

Concerns

Measuring pavement markings can be time consuming and cost prohibitive, depending on the 

quantity of pavement markings to be measured and the measurement technique. However, 

agencies do not necessarily need to purchase their own instruments. Some agencies share 

devices, use loaners from Local Technology Assistance Program (LTAP) centers, or rent them 

from companies. For some agencies, measured retroreflectivity may be best used to support one 

of the other methods. 

Using the retroreflectivity of pavement markings as the only indicator of whether markings need 

to be replaced could result in other attributes of the markings’ overall appearance being 

neglected. Other factors to be considered include the daytime and nighttime color, the presence 

of the marking material, and the uniformity of the nighttime appearance. Agencies also need 

access to the measurement devices and trained personnel to use this method (or the measurement 

services of a third party). 

The measurement bias, repeatability, and reproducibility limits of retroreflectivity measurements 

are also important considerations when using measurements to determine whether pavement 

markings meet the MUTCD minimum levels. ASTM has recently updated the repeatability and 

reproducibility limits for pavement marking retroreflectivity measured with a 30-meter geometry 

handheld instrument (see ASTM E1710).

(20)
July 2022 19

CHAPTER 4. CONSISTENT PARAMETERS NIGHTTIME VISUAL

INSPECTION METHOD

Introduction

Agencies can use the consistent parameters nighttime visual inspection method to conduct visual 

inspections at night without the need for specific calibrated markings or retroreflectivity 

measurements.

1 This method relies on the judgment of an inspector who is at least 60 years old. 

The minimum retroreflectivity levels outlined in the MUTCD are based on research that 

evaluated the visibility needs of 90 percent of drivers, which corresponds to a 62-year-old.

(21)

The pavement marking visibility viewed by an inspector who is 60 years or older can be thought 

of as a surrogate for maintained retroreflectivity that meets the needs of drivers. 

This method involves minimal resource investment on the part of the agency, although there is 

still a need for a record-keeping system for inspection data and the potential for higher labor 

costs where overtime pay at night is needed. While visual inspections reveal night visibility 

problems not discernable under any other method, they are subjective and therefore more 

difficult to tie to a specific retroreflectivity level. As a result, it is important for agencies using 

visual inspections to establish procedures that provide consistency in inspections. This implies 

the need for inspector training and possibly inspector certification. 

Background

Probably the most common type of method used in the past to evaluate pavement marking 

retroreflectivity has been some form of the nighttime visual inspection method. Despite the 

subjectivity and reliability concerns of the method, research has shown visual assessment 

techniques can be used to assess the relative brightness of pavement markings, but not 

necessarily the retroreflectivity level of pavement markings.(12) Therefore, it is important to have 

trained inspectors who follow the process outlined in this section when conducting nighttime 

visual inspections of pavement markings. 

The consistent parameters method uses inspectors aged 60 years or older to observe pavement 

markings during the nighttime to assess the overall appearance of pavement markings and 

determine whether they need to be replaced. The observation is typically done through the 

windshield of the vehicle at or near the speed limit of the roadway. 

Inspector Training

The key to this method is having trained inspectors. While there is no nationally recognized 

training course or certification for pavement marking inspectors, agencies are encouraged to 

provide inspector training before using this method. Elements of proper training include the 

purpose and objectives of the inspection, the types of markings to evaluate, when to conduct the 

1 The term consistent parameters is used to indicate the inspection method uses parameters that are consistent with 

those used during FHWA’s research to develop recommended minimum retroreflectivity levels.

(21)
July 2022 20

inspection, documentation, safety, equipment, appropriate agency policies, and how to make a 

judgment on the adequate visibility of the markings. 

General Procedures

The consistent parameters nighttime visual inspection method is typically conducted using a twoperson crew. While the driver focuses on the driving task, the inspector (aged 60 years or more) 

evaluates the pavement markings and records the appropriate information. Those markings 

judged by the inspector to not meet his or her driving needs are noted as needing to be replaced

(i.e., can the older driver see the markings far enough in advance to make appropriate decisions 

and maneuvers at normal driving speeds?). Although not preferred, an alternative to a twoperson crew is to use one person with a tape recorder or mounted camcorder for recording notes. 

Retroreflectivity assessments need to be made at the time of the inspection by the inspector 

based on his or her nighttime visual needs. Video recordings are not to be used later for 

determining the condition of the markings. Video technology is not yet available that can provide 

the necessary quality to be used in assessing retroreflectivity.

Detailed Procedures

Agencies may find it helpful to develop inspector guidelines and procedures to ensure consistent 

inspections. The following are keys to a successful inspection:

1. Conduct inspections at normal speed and from the travel lane.

2. Conduct inspections using low-beam headlights while minimizing interior vehicle 

lighting.

3. Evaluate markings far enough in advance so that there is adequate time to respond to 

curves, changes in the number of lanes, or marking patterns. 

Since inspections are only conducted with low-beam headlamps, it important to verify the proper 

alignment of the inspection vehicle’s low-beam headlamps (see figure 5).

(22, 23) The ambient 

conditions must be dark: at least 30 minutes beyond sunset. The condition of the pavement must 

be dry during the inspection. Unlike the calibration markings method, there is no equipment 

needed for this method. The only constraints are that the inspector be trained and be at least 60 

years old, that the inspection take place at night, and that the inspection vehicle headlamps be 

properly aimed and set to low beams during the evaluation. The inspection vehicle can be any 

type of passenger vehicle, although a passenger car is preferred because it most closely matches 

the research parameters. The inspections are to be conducted at typical driving speeds and from 

the travel lanes immediately adjacent to the markings being evaluated. 

It is helpful to plan the routes before the inspection begins. The frequency of inspections (e.g., 

once or twice per year) and the sampling procedures are part of the method. Documenting the 

process, including the inspection results, can help prioritize markings replacement schedules. 
July 2022 21

Figure 5. Text. Headlamp aiming procedure.(22)

Linking to Maintained Retroreflectivity Levels

This method links to the minimum retroreflectivity levels in the MUTCD by replicating the 

research conditions under which those levels were established. An objective of the MUTCD 

language is to establish minimum levels of nighttime pavement marking performance based on 

the visibility needs of nighttime drivers, especially older nighttime drivers. This procedure 

provides a technique to do just that. 

Advantages 

One of the major benefits of this method is that it has relatively low equipment, administrative,

and fiscal burdens. Many agencies already perform some type of periodic pavement marking 

inspection although not all inspections are performed at night or with an older inspector. A 

What you will need:

• A level area with a distance of approximately 7.625 meters (25 feet) plus the length of 

the vehicle from a flat, lightly colored wall.

• A tape measure.

• Masking tape.

Instructions:

1. Park the vehicle so that the headlamps are precisely 7.625 meters (25 feet) from a flat,

lightly colored wall. The vehicle should have at least half a tank of gas and should be 

loaded as it would be when inspecting signs. This includes the weight of the driver 

(and passenger if present).

2. Measure the exact middle of both the windshield and rear window, and mark them

with strips of tape, creating vertical centerlines, front and rear.

3. Standing behind the car, sight along the centerlines, and have an assistant mark the 

position of the vehicle centerline on the wall with a vertical strip of tape.

4. Measure the distance between the vehicle centerline and the headlamp lenses. Mark 

that distance to the right and left of the centerline on the wall with vertical strips of 

tape.

5. Measure the height of each headlamp from the ground (measuring to the center of the 

lens). Using those measurements, place horizontal strips of tape on the wall where the 

vertical strips have been applied. There should now be two crosses on the wall, with 

centers that correspond to the center of each headlamp lens.

6. For headlamps with a left-side cutoff, mark a horizontal line that is 53.34 millimeters

(2.1 inches) below the headlamp centers with a horizontal strip of tape. For headlamps 

with a right-side cutoff, mark a horizontal line that runs through the headlamp centers.

7. Turn the vehicle headlamps on low beam. The left edge of the bright spots on the wall 

should just touch the vertical bars of the crosses. The top edge of the strongest 

gradient of light should just touch the horizontal line. Adjust the headlamp aim 

according to the manufacturer’s instructions, if required.
July 2022 22

feature of this method is that the inspectors view the pavement markings in the context of their 

surroundings. Thus, an agency can assess the overall appearance of the pavement markings and 

the ability of the pavement markings to provide information to the driving public.

Using this method, it is possible to assess more than just the retroreflectivity of pavement 

markings. Inspectors may identify other damage, such as excessive wear from turning 

movements. In addition, they can examine current pavement markings to be sure they continue to 

meet MUTCD and other policy standards.

Concerns

This method relies on the judgment of the inspector. Therefore, it is the most subjective of all the 

recommended methods. It is good practice to occasionally conduct spot checks with a 

retroreflectometer to confirm the quality of the agency’s visual inspections. 

While it can be used effectively for the purpose of ensuring markings are replaced before the end 

of their useful service life, it is not feasible to use this method to enforce contracted 

retroreflectivity criteria that come with disincentives if the markings fail a specific level before a 

set period.

Pavement markings supplemented with raised retroreflective pavement markers (RRPMs) can be 

difficult to inspect visually. The brightness of the RRPMs can be much greater than that of the 

pavement markings, and therefore inspectors might find it difficult to judge the pavement 

marking retroreflectivity. Agencies using RRPMs may need to consider a different method.

Pavement markings on either side of the inspection vehicle can be evaluated during a visual 

inspection. However, pavement markings that are not adjacent to the inspection vehicle cannot 

be evaluated during a visual inspection. Therefore, for multilane highways, more than one pass

(per direction) will be needed to inspect all longitudinal markings. This is not unique to this

method.
July 2022 23

CHAPTER 5. CALIBRATED PAVEMENT MARKINGS

NIGHTTIME VISUAL INSPECTION METHOD

Introduction

Agencies can use the calibrated pavement markings nighttime visual inspection method as long 

as steps are taken to calibrate the inspector’s perception of pavement marking retroreflectivity 

levels. While nighttime visual inspections will reveal the retroreflective condition of the 

markings, visual inspections are subjective and therefore more difficult than actual 

measurements to tie to a specific retroreflectivity level. Agencies using visual inspections need to 

establish procedures to provide consistency in inspections. This implies the need for training 

programs and possibly inspector certification. 

This method entails only minor investment on the part of the agency, although there is a need for 

a record-keeping system for inspection data and the potential for higher labor costs where 

overtime pay is needed (because the inspection is performed at night). The significant up-front 

resource needed is a retroreflectometer to measure the calibrated pavement markings to ensure 

they are at the intended retroreflectivity levels. However, agencies do not necessarily need to 

purchase their own instruments. Some agencies share devices, use loaners from LTAP centers, or 

rent them from companies. 

Background

Probably the most common type of method used to evaluate pavement marking retroreflectivity 

has been some form of the nighttime visual inspection method. Despite the subjectivity and 

reliability concerns of the nighttime visual inspection method, research has shown visual 

assessment techniques can be used to assess the relative brightness of pavement markings but not 

necessarily the actual retroreflectivity level of pavement markings.(12) Therefore, it is important 

to have trained inspectors who follow the process outlined in this section when conducting 

nighttime visual inspections of pavement markings. 

The calibrated markings method is a visual inspection method that shares some elements of the 

consistent parameters method. There are two primary differences: 

• It does not restrict the inspector’s age to 60 years or older.

• It requires calibration markings that have retroreflectivity levels at or above the minimum 

levels in the MUTCD. 

With this method, the inspector views the calibration markings and then immediately proceeds to 

perform the nighttime inspection of in-service markings to determine whether they need to be 

replaced. The inspector typically observes the markings through the windshield of the vehicle at 

or near the speed limit of the roadway. The addition of a dedicated driver makes it possible for 

the inspector to concentrate on observing the markings at the appropriate distance. 
July 2022 24

Inspector Training

While there is no nationally recognized training course or certification for pavement marking 

inspectors, agencies are encouraged to provide some form of training for inspectors before they 

perform nighttime inspections. 

Elements of the training include the purpose and objectives of the inspection, critical inspection 

techniques, cautions for improper techniques, the types of markings to evaluate, when to conduct 

the inspection, documentation, safety, equipment, appropriate agency policies and procedures, 

and how to make a judgment on the adequate visibility of the markings using this method. A 

necessary element of the training is to have the inspectors observe sample pavement markings at 

a variety of known retroreflectivity levels, including levels near the MUTCD levels, before 

conducting the inspections. This type of training is needed to help the inspector experience the 

differences between various retroreflectivity levels. Inspectors benefit from viewing the sample 

pavement markings at night under conditions similar to those under which they will perform 

inspections. This includes using the vehicle that will be used during the inspection, using lowbeam headlamps, and locating the calibration pavement markings in positions that replicate most 

typical field applications. 

General Procedures

This method uses trained personnel to observe pavement markings during nighttime conditions 

to assess the overall appearance of the markings and determine whether they meet the MUTCD 

retroreflectivity levels. This method is typically conducted using a two-person crew. While the 

driver focuses on the driving task, the inspector evaluates the pavement markings and records the 

appropriate information. Although the view of the pavement markings is not the same for the 

passenger as the driver, it is similar, and the safety of the inspection procedure is very important. 

Therefore, the use of a two-person crew is a practical and safe way to conduct an inspection 

using this method. The observation is made through the windshield of the vehicle at the normal 

travel speed of the roadway using low-beam headlamps. If the inspector finds a marking appears 

to be approaching or less bright than the calibration markings viewed earlier, then the markings 

are scheduled to be replaced. 

An alternative to a two-person crew is to use one person with a tape recorder or mounted 

camcorder for recording notes. The retroreflectivity assessments need to be made by the 

inspector at the time of the inspection. Video recordings are not to be used later for determining 

the condition of the markings. Video technology is not yet proven to provide the necessary 

quality to be used in assessing retroreflectivity.

Detailed Procedures

To get started, it is helpful for an agency to develop a step-by-step set of instructions for 

consistency of inspections. This method requires a sample of pavement markings at or above the 

MUTCD-established retroreflectivity levels. These markings will be designated as the 

calibration markings. Depending on the agency specifications, the retroreflectivity levels of the 

calibration markings may be at the MUTCD-established levels, or they may be higher but not 
July 2022 25

lower than the appropriate level. The pavement marking retroreflectivity of the calibration 

markings will need to be measured and documented to ensure it is near the desired level. 

Good practice includes both yellow and white calibration markings that are positioned 

accordingly (e.g., for a two-lane, two-way roadway, white on the right and yellow on the left). If 

the calibration pavement markings are installed specifically for this purpose, the contractor or 

installer will need to make special provisions to apply pavement markings near the desired 

levels. This will take some trial and error because the levels will be much lower than typical new 

pavement markings. However, it can generally be achieved by controlling truck speed and bead 

load rates. Retroreflectivity can also be lowered by applying a clear coat of polyurethane or other 

similar product. 

It is important that the inspector evaluate the calibration markings from the vehicle to be used for 

the inspection before each night’s inspection begins. The markings can be viewed in a static or 

dynamic condition. If the calibration markings are set up to be viewed in a static condition, then 

the calibration markings need to be at least 10 feet long and the inspection vehicle positioned

100 feet in advance of the calibration markings. This replicates the 30-meter geometry used in 

instrument measurements. 

Calibration markings used in a dynamic condition (on an existing roadway) need to be long 

enough to provide the inspector at least 15 seconds of preview time to study the brightness of the 

marking. This means that the length of calibration markings to be used in dynamic conditions 

varies with the speed. The intended speed of the inspection vehicle during calibration can be 

used to calculate the length of calibration markings needed. If the agency has pavement markings

on roads open to public travel that are known to be near the minimum levels, these markings may 

be used as calibration markings. However, in this case, the calibration process is performed at the 

posted or operating speed, which necessitates a significant length of calibration marking. For 

example, at 60 mph, calibrated markings at least one-quarter mile long are needed to provide

enough viewing time for the inspector to calibrate his or her eyes. 

When viewing the calibrated markings, the inspector tries to focus about 100 feet in front of the 

vehicle and commit to memory the appearance (or brightness) of the calibrated markings. The 

inspector uses the appearance of the calibrated markings as a benchmark to determine if inservice markings are brighter or less bright than the calibrated markings. Those that are less 

bright and those at about the same brightness level are scheduled for replacement. 

Once a set of pavement markings that are at or near the level(s) set by the agency has been 

installed or identified for use as calibration markings, it is a good practice to measure and 

document the retroreflectivity levels as part of the process. ASTM Test Method D7585(18)

includes a description of the appropriate test method for handheld pavement marking 

retroreflectometers. 

Any type of vehicle can be used for the calibrated pavement markings visual inspection method. 

Since inspections are conducted only with low-beam headlamps, it is important to verify the 

alignment of the low-beam headlamps of the inspection vehicle (see figure 5 in chapter 4). The 

ambient conditions must be dark: at least 30 minutes beyond sunset. The condition of the 

pavement must be dry during the calibration and during the inspection. If calibration markings 
July 2022 26

are viewed in a dynamic condition, at least one pass of the calibration markings must be made, 

but more than one can be beneficial. 

Linking to Retroreflectivity Maintenance Levels

Retroreflectivity levels are incorporated into this method by training the inspectors and using 

procedures that allow them to correlate their inspection observations with known retroreflectivity 

levels through the use of calibrated pavement markings (at or above the MUTCD levels). It is 

important that inspectors observe the calibrated markings prior to each night’s inspection. It is

good practice for inspectors to observe the calibrated pavement markings intermittently 

throughout each nighttime inspection. Therefore, it is helpful to locate the calibrated pavement 

markings in a centralized area and plan the night inspection route so that the calibrated markings 

can be observed several times throughout the night. 

Advantages 

One of the major benefits of using this method is that it has relatively low administrative and 

fiscal burdens. Many agencies already perform some type of periodic pavement marking 

inspection, although not all inspections are performed at night, and few are actually linked to 

retroreflectivity levels. A feature of this method is that the pavement markings are viewed in 

their natural surroundings. Thus, the overall appearance of the pavement marking and the ability 

of the pavement markings to provide information to the driving public can be assessed.

Using this method, it is possible to assess more than just the retroreflectivity of pavement 

markings. Other damage can be identified such as excessive wear on the inside of curves or loss 

of presence (i.e., when some of the pavement marking material is missing), which might not be 

identified with spot retroreflective measurements alone. 

Concerns

This method is somewhat subjective. However, research has shown that inspectors can make 

subjective ratings of pavement marking visibility that can be used as surrogates for 

retroreflectivity (i.e., using qualitative ratings such as poor, marginal, and desired rather than 

specific retroreflectivity levels such as 80 or 115 mcd/m2/lx). There is some safety concern 

involved while performing these inspections, particularly if the driver is also the evaluator and 

recorder. For safety reasons, it is best for two people to conduct nighttime inspections. Including 

additional inspections by different inspectors has been shown to increase the reliability of visual 

inspections. It is also good practice to occasionally conduct spot checks with a retroreflectometer 

to confirm the quality of the agency’s findings.

Agencies using this method will need to establish a protocol that fits their conditions, including 

the frequency of inspections and the establishment of calibrated markings. Part of that protocol 

could be route planning to separate higher-speed roads which need higher retroreflectivity from 

lower-speed roads so that the inspector’s eyes are calibrated for the correct retroreflectivity level 

of the route. Since pavement markings tend to lose their retroreflective performance over time, it 

is important to measure the calibrated markings periodically to ensure that they are at or above 

the appropriate levels. 
July 2022 27

Visual inspections of pavement markings supplemented with RRPMs can be difficult. The 

brightness of the RRPMs is usually much greater than that of the pavement markings, and 

therefore it can be difficult to judge the pavement marking retroreflectivity. Agencies using 

RRPMs may need to consider a different method. 

Pavement markings on either side of the inspection vehicle can be evaluated during a visual 

inspection. However, pavement markings that are not adjacent to the inspection vehicle cannot 

be evaluated during a visual inspection. As a result, for multilane highways, more than one pass 

is needed (per direction) to inspect all longitudinal markings. This is not unique to this method.

July 2022 29

CHAPTER 6. SERVICE LIFE BASED ON HISTORICAL DATA METHOD

Introduction

With this method, an agency documents pavement marking installation dates and, using 

historical retroreflectivity data or research results, develops a schedule for replacing the 

markings. This schedule is designed to prevent the pavement marking retroreflectivity from 

falling below the MUTCD retroreflectivity level. Using this method, agencies can set pavement 

marking replacement schedules for similar markings in similar conditions. 

Procedures

Research shows that the most pertinent factors in determining the service life of pavement 

marking retroreflectivity are pavement marking type (e.g., binder, thickness, and optics), 

pavement surface, snowplow operations, traffic volumes, and climate.

(24, 25) Therefore, it is 

appropriate for agencies using this method to consider these factors when determining the 

service life of their markings. Without the support data on how long pavement markings last 

before reaching a predetermined retroreflectivity level, an agency may find it best to use an 

alternative maintenance method, such as service life based on monitored markings (chapter 7).

To track and schedule replacement of specific markings, the agency can use a computerized 

documentation technique, such as a spreadsheet listing the factors. Alternatively, fully featured 

geographic information systems (GIS) can be developed. Either way, pavement markings of 

similar type can be grouped with roadways under similar conditions. Merging the different 

factors along with an agency’s historical retroreflectivity data enables an agency to use this 

method.

Current Practice

A literature review and agency surveys have shown that the expected service life of pavement 

markings varies considerably across the United States.

(26) Table 1 shows the range of values for 

assorted pavement marking types. The large ranges demonstrate the need to use historical 

retroreflectivity data based on your agency’s or your state’s own conditions.

Table 1. Range of pavement marking service life estimates.

(26)

Pavement Marking Material Type Range of Service Life (Years)

Water-based paints 0.5 to 3.0

Alkyl-based paints 0.25 to 3.0

Epoxy 2.0 to 5.0

Thermoplastics 1.0 to 7.0

Preformed tapes 2.0 to 8.0

Methyl methacrylate 2.0 to 7.0

Polyurea 3.0 to 4.0
July 2022 30

Linking Service Life to Retroreflectivity Maintenance Levels

Either historical retroreflectivity data or research results can be used with this method. 

Regardless of which is used, the expected service life period must be based on the MUTCD

minimum levels or higher levels established by the agency with jurisdiction of the roadway. The 

markings are scheduled for replacement before they reach this point. 

Advantages 

The major benefit of using this method is that, in theory, there is no need to conduct field 

inspections once the service life estimates are generated. However, realizing the differences in 

weather from year to year and the differences in quality of pavement marking applications, it is

advisable to conduct periodic retroreflectivity checks. It will be necessary to establish a

management system so that the installation and replacement cycles can be properly administered. 

For agencies with heavy winter maintenance activities that make annual or more frequent 

striping of their entire network a necessity, this method can be quite effective. Many northern 

agencies currently practice this maintenance method—restriping certain highway systems each 

year with water-based paint. However, these agencies might need to prioritize their restriping 

programs so that they replace their markings as soon as practical after winter conditions and 

consider which roadways may also warrant remarking in the fall. Analyzing historical data might

also trigger consideration for using durable marking materials to keep marking retroreflectivity 

above the MUTCD levels for more of an entire year or even for multiple years at a time.

Concerns

One of the issues with this method is that the replacement times can vary depending on many 

factors. Having reliable service life numbers is important for obtaining the maximum benefit 

from this method. In addition, regional climate plays a critical role in the expected service life.

Having local or regional service life data is important. 

To use this method with durable markings, an agency needs several years of in-service pavement 

marking retroreflectivity data available to estimate the life of the markings. Many agencies have 

established in-house test decks or have contracted with researchers to design and monitor test 

decks. These activities are time consuming but essential in order to properly estimate the service 

life of durable pavement markings. 
July 2022 31

CHAPTER 7. SERVICE LIFE BASED ON MONITORED MARKINGS

METHOD

Introduction

With this method, an agency documents pavement marking installation dates and periodically 

monitors the retroreflectivity of a representative sample of those markings as a way to track their

durability. The agency uses these monitored markings to represent a larger group of similar 

markings in similar conditions. When the monitored markings degrade and approach the 

MUTCD minimum levels, the entire group of markings (both monitored and the larger group 

they represent) are restriped. This is an alternative method for agencies that want to use a service 

life method but do not have historical data or specific research supporting service life estimates 

for their region’s specific conditions (i.e., their in-service life before falling below the MUTCD 

minimum levels).

Procedures

Because markings perform differently depending on several key factors, it is important to have 

monitored markings that represent a reasonable range of these key factors. Considering factors 

such as pavement marking type, binder material, retroreflective optics, pavement surface, 

snowplow operations, climate, and traffic volumes is appropriate because research shows that 

many of these are important factors for the service life of pavement marking 

retroreflectivity.(25, 26) The key assumption with this method is that markings of similar type in 

similar conditions deteriorate at the same rate. Once an agency determines how to stratify the 

markings, it can monitor some of the markings in each of the stratified levels (rather than 

monitoring all markings). 

To track the retroreflectivity of the monitored markings, the agency can use a computerized 

documentation technique, such as a spreadsheet listing the factors. Fully featured GIS systems 

can also be used. Either way, pavement markings of a similar type are grouped with roadways 

having similar conditions. Then, using a specific monitored roadway section or sections 

representing other roadway sections with similar characteristics, the agency tracks the 

retroreflectivity of that specific roadway section. The selected monitored representative section 

of roadway should include as many features and characteristics of the larger common group as 

feasible. When the monitored markings deteriorate and approach the MUTCD-established 

retroreflectivity level, the entire group of markings (both monitored and the larger group they 

represent) are restriped.

The preferred way to monitor markings is the measured retroreflectivity method. However, an 

agency may instead assess the monitored markings using either the calibrated pavement 

markings nighttime visual inspection method or the consistent parameters nighttime visual 

inspection method. The length of the roadway section(s) with the monitored markings needs to 

be long enough to provide a statistical representation of the larger group of markings they are 

meant to represent. 
July 2022 32

Linking Service Life to Retroreflectivity Maintenance Levels

When pavement marking service life is determined by monitoring in-service markings, they must 

be assessed at specified intervals to determine how they are performing with respect to the 

retroreflectivity levels set by the MUTCD. The trending retroreflectivity levels from the 

monitored markings can be used to schedule pavement marking replacement. 

Advantages 

This method involves the inspection of a subset of markings in the field that represent a larger 

group of markings. Agencies must track when each group of pavement markings was installed. 

Using this method, agencies can develop a thorough understanding of pavement marking 

retroreflectivity durability and adjust their policies as field data and pavement marking costs 

indicate. Compared to measuring pavement marking retroreflectivity for all longitudinal 

markings, this method minimizes the need to expose the inspector to traffic and reduces both 

data collection costs and data management needs. 

After a period, an agency can use these data to develop service life values. When an agency 

determines the service life values for its pavement markings, it may transition to the service life 

based on historical data method (chapter 6).

Concerns 

Agencies need to understand what factors or conditions to consider to group their markings 

appropriately and select a representative sample for each group of markings to determine when 

to replace the group of markings. 

While this method has advantages, agencies need to determine how to group similar pavement 

markings and other key factors (such as those listed). In addition, agencies need to determine the 

sampling procedures for the monitored markings (such as those outlined in ASTM D7585[18]) 

and the frequency of inspections. An important aspect of this method is that the pavement 

markings selected to be monitored must be installed on roadways representative of the agency’s 

jurisdiction. Markings cannot be installed in the maintenance yard or another convenient area 

without traffic. Because pavement marking retroreflectivity is so closely tied to pavement 

surface types and traffic volumes, the control method as described for maintenance of traffic sign 

retroreflectivity is not an appropriate method for maintaining pavement marking retroreflectivity. 
July 2022 33

CHAPTER 8. FREQUENTLY ASKED QUESTIONS

This chapter provides some frequently asked questions (FAQs) and the corresponding answers. 

FHWA maintains visibility-related FAQs on the FHWA Office of Safety roadway departure 

nighttime visibility page, https://safety.fhwa.dot.gov/roadway_dept/night_visib/. The web page 

will be updated as additional FAQs are generated.

What Markings Are Subject to the Minimum Maintained Retroreflectivity Levels?

The minimum maintained retroreflectivity applies to all longitudinal pavement markings (i.e., 

center lines, lane lines, and edge lines) on roadways with posted speed limits of 35 mph or 

greater. This includes both temporary and permanent pavement markings. Agencies have the 

option to exclude markings where ambient illumination assures markings are adequately visible 

from their method. Also, markings on streets or highways that have an average daily traffic 

(ADT) of less than 6,000 vehicles per day may be excluded. In addition, dotted extension lines 

(per MUTCD Section 3B.08), curve markings, parking space markings, and shared-use path 

markings may be excluded from an agency’s method. 

Is a Retroreflectometer Required to Use the Pavement Marking Retroreflectivity 

Maintenance Methods Described in This Report?

Not necessarily. This report includes methods that do not require retroreflectivity measurements. 

Some methods only need access to a retroreflectometer for a short time to establish the 

retroreflectivity levels of reference markings. Alternatives to purchasing retroreflectometers

include borrowing devices from LTAP centers or other agencies. Devices are also available for 

rent from some manufacturers. Additional information on handheld and mobile pavement 

marking retroreflectometers can be found in the FAQs on the FHWA Office of Safety roadway 

departure nighttime visibility page, https://safety.fhwa.dot.gov/roadway_dept/night_visib/.

Is an Inventory Necessary?

No. However, the benefits of having an inventory are described for each method in chapters 3 

through 7 of this report. 

Does an Inspector Need to Be at Least 60 Years Old? 

Only for one method, the consistent parameters nighttime visual inspection method. This report

includes several other methods that have no age requirements for inspectors. 

Can I Use Any Vehicle for the Nighttime Inspection Methods?

No, the vehicle must be a passenger vehicle. It is also important to use low-beam headlamps 

during the inspections. For the consistent parameters method, a sedan is preferred because it 

most closely matches the research parameters. However, other passenger vehicles are acceptable, 

such as a sports utility vehicle or light truck. 
July 2022 34

Are Annual Inspections Frequent Enough?

Typically, yes, if an agency already has data showing rates of deterioration, although it might

depend on the amount of traffic, snowplow operations, and durability of the marking materials. 

A good practice is to inspect more frequently until a database is built showing rates of 

deterioration to know if markings are providing adequate retroreflectivity throughout much of 

the year. Inspecting at a time of year when markings are typically near the end of their expected 

service life might assist in decisions regarding upgrading to longer-life marking materials.

Is Documentation of My Inspections Required?

No. Although it is not required, it is a good practice. Agencies that document their maintenance 

method and maintenance activities may realize benefits in terms of budgeting resources, defense 

against litigation, etc.

What If I Cannot Restore All Markings According to the Replacement Schedule?

The MUTCD requires the use of “a method designed to maintain retroreflectivity at or above...”

If your implementation of the maintenance method is designed to maintain your markings above 

the minimum values, you would be considered to be in compliance with the standard. 

Unanticipated events may occur that cause delays in reapplication. If unanticipated events occur, 

compliance with the standard is still considered to be achieved as long as a reasonable course of 

action is taken to resume maintenance of minimum retroreflectivity in a timely manner according 

to your agency’s method(s), policies, and procedures. See paragraph 8 of 2009 MUTCD 

Section 3A.03.

Am I Allowed to Use Resources or Take Actions outside My Written or 

Documented Method and Still Be Considered in Compliance?

An agency is responsible for maintaining pavement markings regardless of whether the method 

is documented. While detailed documentation is useful for business practices and consistency, it 

is unlikely to address every event or circumstance. For example, an agency would be prudent to 

schedule reapplication of markings on sections of abnormal wear that are discovered during 

inspections or routine maintenance, even if that is not part of its written procedure or typical 

practice. 
July 2022 35

REFERENCES

1. Federal Highway Administration. FHWA FY 2019–2022 Strategic Plan. Available at 

https://www.fhwa.dot.gov/policy/fhwaplan.cfm (Accessed September 1, 2016).

2. National Highway Traffic Safety Administration. Traffic Safety Facts 2019 Data. DOT 

HS 813 209, November 2021. Available at

https://crashstats.nhtsa.dot.gov/Api/Public/ViewPublication/813209 (Accessed June 1, 

2022).

3. Federal Highway Administration. 2001 National Household Travel Survey. Available at

http://nhts.ornl.gov (Accessed September 1, 2016).

4. Federal Highway Administration. Nighttime Visibility. Available at 

http://safety.fhwa.dot.gov/roadway_dept/night_visib/general-information.cfm (Accessed 

September 1, 2016).

5. Sun, X., and S. Das. A Comprehensive Study on Pavement Edge Line Implementation. 

FWHA/LA.13/508, April 2014.

6. Tsyganov, A., R. Machemehl, and N. Warrenchuk. Safety Impact of Edge Lines on Rural 

Two-Lane Highways in Texas. FHWA/TX-05/0-5009-1, September 2005.

7. Carlson, P.J., E.S. Park, and D.H. Kang. An Investigation of Longitudinal Pavement 

Marking Retroreflectivity and Safety. Transportation Research Record: Journal of the 

Transportation Research Board, 2337 (2013).

8. Smadi, O., R. Souleyrette, D. Ormand, and N. Hawkins. Pavement Marking 

Retroreflectivity: Analysis of Safety Effectiveness. Transportation Research Record: 

Journal of the Transportation Research Board, 2056 (2008).

9. National Highway Traffic Safety Administration. Traffic Safety Facts 2019 Data. DOT 

HS 813 209, November 2021. Available at 

https://crashstats.nhtsa.dot.gov/Api/Public/ViewPublication/813209 (Accessed June 1, 

2022).

10. Federal Highway Administration. Handbook for Designing Roadways for the Aging 

Population. FHWA-SA-14-015, June 2014. 

11. Carlson, P.J., E.S. Park, and C.K. Andersen. The Benefits of Pavement Markings: A 

Renewed Perspective Based on Recent and Ongoing Research. Transportation Research 

Record: Journal of the Transportation Research Board, 2107 (2009). 

12. Carlson, P.J. Synthesis of Pavement Marking Research. FHWA-SA-15-063, U.S. 

Department of Transportation, 2015. Available at 

http://safety.fhwa.dot.gov/roadway_dept/night_visib/pavement_marking/ (Accessed May 

11, 2016).
July 2022 36

13. Federal Highway Administration. Manual on Uniform Traffic Control Devices. 2009. 

Available at https://mutcd.fhwa.dot.gov/ (Accessed September 1, 2016).

14. Carlson, P.J., and J.D. Miles. Nighttime Visibility of In-Service Pavement Markings, 

Pavement Markers, and Guardrail Delineation in Alaska (with and without Continuous 

Lighting). FHWA-AK-RD-11-04, Alaska Department of Transportation, 2011.

15. Illuminating Engineering Society of North America. Recommended Practice: Lighting 

Roadway and Parking Facilities. ANSI/IES RP-8-21, 2021.

16. American Association of State Highway and Transportation Officials. Roadway Lighting 

Design Guide, 7th Edition. 2018.

17. Falk, K.W., and P.J. Carlson. Pavement Marking Retroreflectivity Workshops Summary 

Report. FHWA-SA-08-003, Federal Highway Administration, February 2008. 

18. ASTM International. ASTM D7585/D7585M, Standard Practice for Evaluating 

Retroreflective Pavement Markings Using Portable Hand-Operated Instruments. 2015.

19. Highway Innovation Technology Evaluation Center. Summary of Evaluation Findings for 

30-Meter Hand-Held and Mobile Pavement Marking Retroreflectometers. Report 40525, 

2001.

20. ASTM International. ASTM E1710, Standard Test Method for Measurements of 

Retroreflective Pavement Marking Materials with CEN-Prescribed Geometry Using a 

Portable Retroreflectometer. 2018. 

21. Deballion, C., P. Carlson, Y. He, T. Schnell, and F. Aktan. Updates to Research on 

Recommended Minimum Levels for Pavement Marking Retroreflectivity to Meet Driver 

Night Visibility Needs. FHWA-HRT-07-059, Federal Highway Administration, 2007.

22. Carlson, P.J., and M.S. Lupes. Methods for Maintaining Traffic Sign Retroreflectivity. 

FHWA-HRT-08-026, Federal Highway Administration, 2007.

23. Gibbons, R., and C. Moulton. Enhanced Night Visibility Series, Volume XVII: Phases II 

and III—Characterization of Experimental Vision Enhancement Systems. FHWA-HRT04-148, Federal Highway Administration, 2005.

24. Migletz, J., J.L. Graham, D.W. Harwood, and K.M. Bauer. Service Life of Durable 

Pavement Markings. Transportation Research Record: Journal of the Transportation 

Research Board, 1749 (2001).

25. Sathyanarayanan, S., V. Shankar, and E.T. Donnell. A Weibull Analysis of Pavement 

Marking Retroreflectivity Inspection Data. Transportation Research Record: Journal of 

the Transportation Research Board, 2055 (2008).

26. Migletz, J., and J. Graham. NCHRP Synthesis 306: Long-Term Pavement Marking 

Practices. Transportation Research Board, 2002.
July 2022 37

APPENDIX A: FINAL RULE—PAVEMENT MARKING

RETROREFLECTIVITY MUTCD TEXT

Add a row to Table I-2, Target Compliance Dates Established by FHWA:

2009 

MUTCD 

Section 

Number(s)

2009 MUTCD 

Section Title Specific Provision Compliance Date

3A.03

Maintaining 

Minimum 

Retroreflectivity 

Implementation and 

continued use of a 

method that is designed 

to maintain 

retroreflectivity of 

longitudinal pavement 

markings (see Paragraph 

1)

4 years from the effective date 

of this revision of the MUTCD

Add a new reference document to Section 1A.11, Relation to Other Publications:

Section 1A.11

“Methods for Maintaining Pavement Marking Retroreflectivity,” (FHWA-SA-22-028), 2020 Edition 

(FHWA)

Revise Section 3A.03 as follows:

Section 3A.03 Maintaining Minimum Retroreflectivity

Standard:

01 Except as provided in Paragraph 5, a method designed to maintain retroreflectivity 

at or above 50 mcd/m2/lx under dry conditions shall be used for longitudinal markings on 

roadways with speed limits of 35 mph or greater. 

Guidance:

02 Except as provided in Paragraph 5, a method designed to maintain retroreflectivity at or 

above 100 mcd/m2/lx under dry conditions should be used for longitudinal markings on 

roadways with speed limits of 70 mph or greater.

03 The method used to maintain retroreflectivity should be one or more of those described in 

“Methods for Maintaining Pavement Marking Retroreflectivity” (see Section 1A.11) or developed from 

an engineering study based on the values in Paragraphs 1 and 2.

Support:

04 Retroreflectivity levels for pavement markings are measured with an entrance angle of 88.76 

degrees and an observation angle of 1.05 degrees. This geometry is also referred to as 30-meter geometry. 

The units of pavement marking retroreflectivity are reported in mcd/m2/lx, which means millicandelas per 

square meter per lux. 

Option:

05 The following markings may be excluded from the provisions established in Paragraphs 1 and 2: 

A. Markings where ambient illumination assures that the markings are adequately visible;
July 2022 38

B. Markings on streets or highways that have an ADT of less than 6,000 vehicles per day; 

C. Dotted extension lines that extend a longitudinal line through an intersection, major driveway, or 

interchange area (see Section 3B.08);

D. Curb markings;

E. Parking space markings; and

F. Shared-use path markings.

Support:

06 The provisions of this Section do not apply to non-longitudinal pavement markings including, but 

not limited to, the following:

A. Transverse markings;

B. Word, symbol, and arrow markings;

C. Crosswalk markings; and 

D. Chevron, diagonal, and crosshatch markings.

07 Special circumstances will periodically cause pavement marking retroreflectivity to be below the 

minimum levels. These circumstances include, but are not limited to, the following:

A. Isolated locations of abnormal degradation; 

B. Periods preceding imminent resurfacing or reconstruction; 

C. Unanticipated events such as equipment breakdowns, material shortages, and contracting 

problems; and

D. Loss of retroreflectivity resulting from snow maintenance operations. 

When such circumstances occur, compliance with Paragraphs 1 and 2 is still considered to be achieved if 

a reasonable course of action is taken to resume maintenance of minimum retroreflectivity in a timely 

manner according to the maintaining agency’s method(s), policies, and procedures.
July 2022 39

APPENDIX B: METHOD DEVELOPMENT

Getting Started

This appendix provides examples of how an agency might implement each of the maintenance 

methods described in the main body of this report. The method development examples provided 

here are geared toward smaller local agencies with limited expertise in developing and 

implementing a method. 

Maintenance Methods

The Manual on Uniform Traffic Control Devices (MUTCD) requires agencies to use a method 

and recommends one or a combination of the methods described in the main body of this report. 

These methods are designed to help agencies continually maintain retroreflectivity of 

longitudinal pavement markings at or above the MUTCD specified minimum levels (i.e., the 

required minimum of 50 mcd/m2/lux and the recommended minimum of 100 mcd/m2/lux for 

higher speed roads). The primary outcome of each of these methods is the timely scheduling and 

replacing of all deficient markings whether measured, visually inspected, or scheduled based on 

service life. See Chapter 2 for a brief summary of the methods, and chapters 3 through 7 for 

more detail on each method. 

Agencies will need to personalize the basic method they choose to make it work for their specific 

situation. The examples shown here are included to help agencies work through this process to 

document their agency-specific method. These examples refer to retroreflectivity thresholds that 

an individual agency can set higher than the appropriate minimum level in the MUTCD to assist 

in scheduling markings for replacement before they become deficient for nighttime driving 

visibility.

Regardless of how an agency chooses to maintain pavement marking retroreflectivity, 

documentation of the process can be beneficial for many reasons. Written procedures help ensure 

that agency personnel properly follow the selected method, and maintenance records provide the 

agency with a systematic process for scheduling replacements and justification for the allocation 

of limited resources. 

Deciding Which Roads and Markings to Include in the Method

The first step for each agency is to determine if they have pavement markings that meet the 

criteria to which the standard in the MUTCD applies. Some agencies may not be required to 

have a method if they only own and maintain very low speed roads. Some may choose not to 

implement a method if all their roadways have adequate lighting or low volumes that allow for 

exclusion under the option. Check the MUTCD to determine whether your agency is required to 

implement a method, keeping in mind future changes such as growth in traffic volumes. 

Markings to which the standard does not apply (e.g. roads with speed limit less than 35 mph) 

must still be retroreflective (see 2009 MUTCD Section 3A.02), but they can be excluded from an 

agency’s pavement marking retroreflectivity maintenance method (Section 3A.03). To maintain 

adequate marking visibility on all roads open to public travel, agencies are encouraged to think 
July 2022 40

about and plan for the maintenance of markings that are not required by the MUTCD to be 

included in the maintenance method.

If an agency that does have pavement markings requiring a maintenance method decides to limit 

their method to certain roads and markings based on the flexibility in the standard, guidance, and 

option statements in the MUTCD, they will need to determine which roads and markings will not 

be included in the method. The following questions can help an agency decide which to include: 

• Will roads with speed limits less than 35 mph be included?

• Will other longitudinal markings beyond center lines, edge lines, and lane lines be 

included (e.g. curb markings)?

• Will any non-longitudinal markings be included (e.g. crosswalks)?

• Will an average daily traffic (ADT) threshold be used to reduce the amount of roadway 

covered by the method? If so, will the threshold be lower than the 6,000 vpd allowed by 

the MUTCD option to account for future growth or based on crash data?

• Are there roadway segments that will be excluded because they have roadway lighting?

The various maintenance methods have different information needs, costs, and level of effort to 

implement. However, regardless of the method, agencies might find it beneficial to create an 

inventory (e.g., an electronic database is helpful) of the roadways and markings to be included in 

the maintenance method. Such an inventory could include, but not be limited to, the following: 

• Road name/number.

• Section beginning and endpoint (e.g., milepost, section number, etc.).

• Roadway classification.

• Volume range or ADT.

• Speed limit.

• Pavement surface type.

• Winter maintenance activity level (e.g. frequency of plowing).

• Pavement marking material (i.e., substrate and retroreflective elements).

• Color and type of markings.

• Installation date.

• Installation method (i.e. applied to surface or inlaid).

• Limits of installation.

The inventory and some of the items listed above are more important to certain maintenance 

methods. That will be discussed under the examples for each method. 

Table B1 provides a summary of the information and data needs for each maintenance method.
Measured Retroreflectivity Method

July 2022 41

Table B1. Maintenance method information and data needs.

Information/Data

Needs

METHOD

Measured 

Retroreflectivity

Consistent 

Parameters

Nighttime 

Visual 

Inspection

Calibrated 

Pavement 

Markings 

Nighttime 

Visual 

Inspection

Service 

Life Based 

on 

Historical 

Data

Service 

Life Based 

on 

Monitored 

Markings

Roadway Sections and 

Markings to Include in 

the Maintenance 

Method

    

Retroreflectivity

Measurements

 +

Nighttime Visual 

Evaluation

  

Inspector 60 Years or 

Older

 

Markings of Known

Retroreflectivity (at or 

above minimum level)

 

Historic 

Retroreflectivity

Degradation Data or 

Marking Service Life 

Data



Database or Records of 

Marking Installation 

Information

+ + +  

Database or Records of 

Roadways/Markings 

with Similar Conditions 

and Characteristics

+ + + + 

Database or Records of 

Inspection Data and/or 

Findings

+ + + +

 = Essential

+ = Suggested

 = Alternative to suggested

Method Development: Measured Retroreflectivity 

Method Definition

In this method, pavement marking retroreflectivity is measured and directly compared to the 

minimum levels in the MUTCD. The retroreflectivity measurements can be made with either 

handheld or mobile instruments (i.e., retroreflectometers) using the standard 30-meter geometry. 
Measured Retroreflectivity Method

July 2022 42

Inspectors should follow the instructions provided by the manufacturer to obtain reliable 

retroreflectivity readings, including periodically calibrating the equipment. Handheld 

retroreflectometers are placed on the pavement marking, while mobile retroreflectometers are 

attached to a vehicle and measure the pavement marking retroreflectivity as the instrumented 

vehicle is driven at typical roadway speeds. Both types of retroreflectometers provide objective 

retroreflectivity values that can be used in direct comparison to the MUTCD levels. 

This example only covers the measured retroreflectivity method using a handheld 

retroreflectometer.

Method Needs

To successfully implement a measured retroreflectivity maintenance method that uses a handheld 

retroreflectometer, the following will be needed: 

• Roadways and markings to be included in the maintenance method.

• Handheld retroreflectometer to use for measuring retroreflectivity.

• Marking retroreflectivity measurement plan.

• Trained inspector.

Method Implementation

This example includes potential steps for an agency to consider when establishing a measured 

retroreflectivity maintenance method for pavement marking retroreflectivity using a handheld 

retroreflectometer. Agencies are encouraged to customize the method to local conditions and 

agency practices. 

1. Using the MUTCD and the information in the “Getting Started” section of this appendix, 

determine which markings will be included in your agency’s method. If the agency 

chooses to develop an inventory, specific information on the pavement marking 

materials, pavement type, and volume is not critical for the measured retroreflectivity 

method because all markings included in this maintenance method are measured. 

However, agencies might find it useful to gather such information to use in projecting 

when the markings will reach the minimum levels, so they can plan to have the markings 

replaced before that time. This information will also be valuable for evaluating the cost 

effectiveness of various marking materials and for future planning purposes. With this 

type of information, an agency can potentially reduce the number of miles to measure by 

measuring a representative sample of the markings included in the method or reducing 

the frequency of measurements on newer durable markings known to have 

retroreflectivity well above the appropriate minimum level. 

2. Purchase or arrange to borrow a handheld retroreflectometer to use for measuring 

retroreflectivity if your agency does not have one. 

3. Select a documentation procedure to record pavement marking retroreflectivity values 

and schedule the replacement of specific markings. This documentation and scheduling 

of replacement markings could be a list, spreadsheet, or database and might also include 

maps or geographic information system (GIS) components. Some retroreflectometers will 
Measured Retroreflectivity Method

July 2022 43

retain data such as measurements and averages, as well as latitude/longitude, however, 

the agency will likely want to keep records that are tied to specific markings and roads 

for use in making decisions about replacement schedules. 

4. Provide inspector training or contract out the work. The company selling the 

retroreflectometer is best suited to provide training for proper use of the device. Specific 

calibration procedures and maintenance schedules for the equipment are important to 

follow to obtain accurate and repeatable measurements.

5. Establish a plan for conducting retroreflectivity measurements per ASTM 

D7585/D7585M, Standard Practice for Evaluating Retroreflective Pavement Markings 

Using Portable Hand-Operated Instruments.

2 Consider the following in your plan: 

a. Establish the number of evaluation sections needed within each roadway segment 

to be measured. For example, in a 20-mile segment with similar markings and 

traffic volume, an agency might randomly select five individual miles that will be 

measured in a particular year. 

b. Plan to take measurements at a time when the pavement will be dry. 

c. Select the specific location of each evaluation section to be measured (e.g. the 

Milepost 1–2, 4–5, etc.). To reduce traffic control, it will likely be most efficient 

to use the same sections for edge lines as center lines.

6. Conduct field measurements using the following steps for each roadway section being 

evaluated.

a. Calibrate the retroreflectometer each day before beginning measurements and 

periodically check the calibration throughout the day.

b. Set-up appropriate MUTCD Part 6 compliant traffic control measures to provide 

safe conditions for inspectors.

c. Take 16 or more measurements at regular intervals within the evaluation section, 

ensuring the retroreflectometer is aligned with the direction of traffic appropriate 

to that line. If measuring a single center line, take measurements in both 

directions. 

d. Document the individual readings and the average for the section.

e. Move to the next line (e.g., if measuring center and edge lines) or the next 

evaluation section.

7. Compare the average measurements with retroreflectivity thresholds chosen by your 

agency. Typically, thresholds are set above the MUTCD minimum levels so that 

markings are replaced before they reach the minimum level.

8. Schedule markings to be replaced as needed. Determine how best to prioritize 

replacement based on retroreflectivity levels, upcoming projects, and weather conditions 

that limit striping seasons.

2 ASTM International. ASTM D7585/D7585M, Standard Practice for Evaluating Retroreflective Pavement 

Markings Using Portable Hand-Operated Instruments, 2015 is the current version and is available for purchase at 

https://www.astm.org/Standards/D7585.htm
Measured Retroreflectivity Method

July 2022 44

9. Update the marking inventory as needed after restriping activities have occurred (e.g. if 

using a new type of material and tracking service life). 

10. Assess and update the maintenance method and supporting information as necessary. 

Consider if additional roadways and their markings need to be added. 

Examples

Figure B1 shows an example of a map that could be developed by a local agency to depict the 

roadway segments (dashed black lines) with markings that need to be included in the 

maintenance method. Figure B2 shows all of the roadway segments (short dashed green lines) 

that are being evaluated with retroreflectivity measurements within the next year. In this example 

the remaining roadway segments will not be evaluated this year because they are already 

scheduled for restriping or are not planned for retroreflectivity evaluation for at least another 

year (due to the use of durable pavement markings that were recently installed and 

retroreflectivity verified). These maps could be produced in conjunction with a spreadsheet 

database. The results of the retroreflectivity evaluations would be compared to the appropriate 

MUTCD minimum level or agency threshold and scheduled for restriping as necessary.

An inventory example is shown in Table B2. Each roadway to which the method applies would 

be included, although the example only shows a small sample. The data collected in the field, 

such as inspection dates and corresponding retroreflectivity measurements, are used to update the 

inventory. Planned restriping activities or the next anticipated inspection date would be helpful to 

include as well. The inventory can group similar roadway types or be organized according to a 

planned inspection route to make implementing the method easier. The spreadsheet could be 

supplemented or replaced with a GIS database or map system.
Measured Retroreflectivity Method

July 2022 45

Figure B1. Diagram. Roadways to be included in the method.

Figure B2. Diagram. Roadways included in method and evaluated this year.
Measured Retroreflectivity Method

July 2022 46

Table B2. Spreadsheet example of roadway database for measured retroreflectivity.

Road Name (Segment Identification

3

)

Segment Length and LimitsFunctional ClassificationTraffic Volume (ADT)Speed Limit (mph)Pavement SurfacePavement Marking Material

4

Winter MaintenanceLine Type(s)Installation DatePrevious Retroreflectivity Measurement and Date EvaluatedNext Retroreflectivity Measurement DateScheduled for Restriping

5

Notes

6

Main St., 

Upshaw 

County

0.8 miles

(Bambin

o Ln to 

Rt 30)

Local 9,500 45 asphalt

water-based paint, 

15 mils, AASHTO 

M247 Type I 

beads

None

edge lines, 

center lines, 

lane lines

4/14/19

March 2020, 

white = 85, 

yellow = 60

None, 

schedule for 

restripe

Yes

Route 202

(Control 

Section 1-

66)

7.6 miles 

(US 28 to 

Jansen 

Dr.)

Minor 

Arterial 10,000 50 asphalt spray thermoplastic None edge lines, lane lines 5/17/19 None Fall 2020 No

Expected 

service life 

over 2 years

Jansen 

Drive, 

Upshaw 

County 

3 miles 

(Main St. 

to Ret 

202)

Local 6,000 40 asphalt water-based paint None edge lines, 

center lines 4/15/19

March 2020, 

white = 120, 

yellow = 105

Late 2020 No

Has overhead 

lighting, keep 

on retro 

monitoring 

program

... ... ... ... ... ... ... ... ... ... ... ... ... ...

... ... ... ... ... ... ... ... ... ... ... ... ... ...

3 Unique road segment identifier (if used by agency).

4 Marking binder and reflective optic types, material thickness, application methods, etc.

5 Has the section been scheduled for restriping?

6

Include notable site characteristics and other notes.
Consistent Parameters Nighttime Visual Inspection Method

July 2022 47

Method Development: Consistent Parameters Nighttime Visual Inspection

Method Definition

In this method, an agency conducts nighttime visual inspections without the need for specific 

calibrated markings or retroreflectivity measurements. This method relies on the judgment of a

trained inspector who is at least 60 years old. The minimum retroreflectivity levels outlined in 

the MUTCD are based on research that evaluated the visibility needs of 90 percent of drivers, 

which corresponds to a 62-year-old. The pavement marking visibility viewed by an inspector 

who is 60 years or older can be thought of as a surrogate for maintained retroreflectivity that 

meets the needs of drivers.

Method Needs

To successfully implement a consistent parameters nighttime visual inspection method, the 

following will be needed: 

• Roadways and markings to be included in the method.

• Inspection vehicle with properly aligned low-beam headlamps.

• Trained inspector (age 60 years or over).

• Driver.

Method Implementation

This example includes potential steps for an agency to consider when establishing a consistent 

parameters nighttime visual inspection method for pavement marking retroreflectivity. Agencies 

are encouraged to customize the method to local conditions and agency practices. 

1. Using the MUTCD and the information in the “Getting Started” section of this appendix, 

determine which markings will be included in your agency’s method. If your agency 

chooses to create an inventory, the most critical information will be the location identifier 

and the type of markings (i.e., edge line, center line, and lane line) so that your inspector 

can document which markings need to be replaced. It is worth noting the presence of 

raised reflective pavement markers (RRPMs) since visual inspections of pavement 

markings supplemented with RRPMs can be difficult. The brightness of RRPMs in good 

condition is usually much greater than that of the pavement markings, and therefore it can 

be difficult to judge the pavement marking retroreflectivity. Other information, such as 

the type of pavement marking material, can be useful if your agency is using the 

information from the inspections for future planning. 

2. Select a documentation technique to track/schedule the replacement of specific markings. 

This tracking and scheduling of replacement markings can be a list, spreadsheet, or 

database and might also include maps or GIS components.

3. Select the vehicle to be used for inspection. The inspection vehicle can be any type of 

passenger vehicle, although a passenger car is preferred because it most closely matches 

the research parameters. Check the vehicle to ensure that the low-beam headlamps are 
Consistent Parameters Nighttime Visual Inspection Method

July 2022 48

properly aligned prior to performing inspections (see Figure 5 in the main body of this 

report). 

4. Select the inspection crew. This method is typically conducted using a two-person crew. 

While the driver (of any age) focuses on the driving task, the inspector (age 60 or older) 

evaluates the pavement markings and records the appropriate information. Although the 

view of the pavement markings is not the same for the passenger as the driver, it is 

similar, and the safety of the inspection process is important. Therefore, the use of a twoperson crew is a practical and safe way to conduct an inspection using this method. The 

observation is made through the windshield of the vehicle at the normal travel speed of 

the roadway using low-beam headlamps.

• Note: An alternative to a two-person crew is to use one person with a tape 

recorder or mounted camcorder for recording notes. The retroreflectivity 

assessments need to be made by the inspector at the time of the inspection. Video 

recordings are not to be used later for determining the condition of the markings 

because video technology is not yet proven to provide the necessary quality to be 

used in assessing retroreflectivity.

5. Conduct inspector training. Agency specific inspector guidelines and procedures can help 

to ensure consistent inspections. While there is currently no nationally recognized 

training course or certification for pavement marking inspectors, agencies are encouraged 

to provide some form of training for inspectors before they perform nighttime 

inspections. Elements of the training might include:

a. Purpose and objectives of the inspection.

b. Critical inspection techniques and cautions for improper techniques.

c. Types of markings to evaluate.

d. When to conduct the inspection.

e. Documentation.

f. Safety.

g. Equipment.

h. Appropriate agency policies and procedures.

i. How to rate in-service markings to provide adequate information to determine 

scheduling for markings (e.g. need immediate replacement, replace before 

winter).

6. Develop the route plan, considering pavement markings that are not adjacent to the 

inspection vehicle cannot be evaluated during a visual inspection. As a result, one pass in 

each direction is needed for two-lane roads and more than one pass is needed per 

direction to inspect all longitudinal markings on multilane roads. 

7. Perform the nighttime visual inspection. 

a. The ambient conditions must be dark—at least 30 minutes beyond sunset—and 

the condition of the pavement must be dry during the inspection. 

b. The inspector observes the pavement markings through the windshield of the 

vehicle at the normal travel speed of the roadway using low-beam headlamps. 
Consistent Parameters Nighttime Visual Inspection Method

July 2022 49

c. The inspector rates each marking adjacent to the vehicle, considering whether it 

can be seen far enough in advance to make appropriate decisions and maneuvers 

at normal driving speeds. The inspector uses a dimmed7light or a computer 

dimmed for nighttime viewing to take notes to avoid corrupting the inspection 

process by in-vehicle illumination that would impact proper viewing of the 

roadway and pavement markings. 

8. Schedule markings to be replaced, as needed, based on the inspector’s rating. Determine 

how best to prioritize replacement based on ratings, upcoming projects, and weather 

conditions that limit striping seasons. 

9. Update the marking inventory as needed after restriping activities have occurred (e.g. to 

indicate date markings were replaced and type of material used).

10. Assess and update the maintenance method and supporting information as needed. 

Consider if additional roadways and their markings need to be added. 

Examples

Table B3 shows a hypothetical example of an inspection data collection sheet that could be used 

by inspectors. The sheet indicates the general location of the nighttime inspection, who 

conducted the inspection, what vehicle was used, and when the inspection occurred. Each row 

indicates a homogeneous roadway section in a specific travel direction. The inspector indicates 

the rating for markings and records notes on each section as appropriate.

An inventory example is shown in Table B4. Each roadway to which the method applies would 

be included, although the example only shows a small sample. Field data such as evaluation 

dates and corresponding inspection ratings are used to update the inventory. Planned restriping 

activities or the next anticipated evaluation date would be helpful to include as well. The 

inventory can be organized according to planned inspection routes or similar roadway types to 

make implementing the method easier. The spreadsheet could be supplemented or replaced with 

a GIS database or map system.

7 A red dimmed light is preferable over a white light to reduce the impact on the observer’s night vision.
Consistent Parameters Nighttime Visual Inspection Method

July 2022 50

Table B3. Example inspection data collection sheet for consistent parameters nighttime visual inspection.

Pavement Marking Retroreflectivity Inspection Report

Inspector Name: J. Garcia Inspector Age: 62 Agency/Location: Washington County, central section

Driver: A. Smith Vehicle Number: 24 Date: 3/25/2021 Time: 8:30 pm to 11:00 pm

Roadway Section 

Identifier

Section 

Limits

Travel 

Direction

MARKING RATING8

Center Line Notes

or Left Edge 

Line (yellow)

Lane Line

(white)

Right Edge 

Line (white)

CR 11 3A CL to MP4 EB A N/A9 A

CR 11 3B MP4 to MP7 EB B N/A A

CR 11 3C MP7 to MP12 EB B N/A B

CR 11 3D MP12 to I-11 EB A N/A B RPMs present

Main St. N/A All NB D D D Right edge captured on 2nd pass

Main St. N/A All SB F F D Right edge captured on 2nd pass

Green Ln. N/A All NB C N/A B

Green Ln. N/A All SB C N/A B Contrast with pavement is not good

CR 6 N/A All SB C N/A N/A Yellow marking color is fading

CR 6 N/A All NB D N/A N/A Close to failing

 

 

 

8 Ratings: A = Excellent, B= Very good, C= Acceptable, D = Marginal, F = Fail.

9 Not applicable because marking type was not present (e.g. no lane lines on two-lane, two-way road or no edge lines on two-lane road).
Consistent Parameters Nighttime Visual Inspection Method

July 2022 51

Table B4. Spreadsheet example of roadway database for consistent parameters nighttime visual inspection.

Road Name (Segment Identification10

)

Segment Length and LimitsFunctional ClassificationTraffic Volume (ADT)Speed Limit (mph)Pavement SurfacePavement Marking MaterialMarking ThicknessReflective OpticsWinter MaintenanceLine Type(s)11Installation DateScheduled for Restriping?Previous Inspection Rating12 and Date EvaluatedNotes13

Main 

Street

2.6 miles 

(Justin 

Blvd to 

14th Ave)

Minor 

Arterial 11,000 50 asphalt water-based paint 15 mils

AASHTO 

M247

Type I

Low EL, CL, 

LL 4/14/19 No All Very Good, March 2020

Main 

Street

1.7 miles 

(14th Ave 

to city 

limit)

Minor 

Arterial 7,200 50 asphalt water-based paint 15 mils

AASHTO 

M247

Type I

Low EL, CL, 

LL 4/14/20 No None

University 

Drive

4.2 miles 

(Rte 1 to 

Rte 18)

Major 

Arterial 17,000 40 asphalt spray thermoplastic 90 mils

Double 

Drop Type 

II and III

Low EL, CL, 

LL 5/18/19 Spring 2021

White Marginal, 

Yellow Fail 

March 2020

Has overhead 

lighting, keep on 

retro monitoring 

program.

14th Ave

0.5 miles 

(Main St 

to Jay St)

Local 5,500 35 asphalt water-based 

paint 15 mils

AASHTO 

M247

Type I

None CL 8/14/19 No

White 

Acceptable, 

Yellow 

Marginal March 

2020

Include in method 

due to expected 

increase in ADT

... ... ... ... ... ... ... ... ... ... ... ... ... ...

... ... ... ... ... ... ... ... ... ... ... ... ... ...

... ... ... ... ... ... ... ... ... ... ... ... ... ...

10 Unique road segment identifier (if used by agency).

11 CL = center line, EL = edge line, LL = lane line.

12 Ratings: Excellent, Very Good, Acceptable, Marginal, Fail.

13 Include notable site characteristics or other notes.
Calibrated Pavement Markings Nighttime Visual Inspection Method

July 2022 52

Method Development: Calibrated Pavement Markings Nighttime Visual Inspection

Method Definition

In this method, an agency conducts nighttime visual inspections using a trained inspector’s 

perception of pavement marking retroreflectivity levels in the field. With this method, the trained 

inspector views calibrated pavement markings of known retroreflectivity at night prior to 

conducting a nighttime visual inspection. The calibrated pavement markings are set up where the 

inspector can view them in a manner similar to the conditions of the nighttime visual inspections. 

The inspector uses the appearance of the calibrated markings as a benchmark to rate in-service 

markings. 

Method Needs

To successfully implement a nighttime visual inspection method that uses calibrated markings, 

the following will be needed: 

• Roadways and markings to be included in the method.

• Calibration markings at or above the MUTCD minimum level(s) or agency threshold(s).

• Inspection vehicle (any type) with properly aligned low-beam headlamps.

• Trained inspector (a specific age is not required).

• Driver.

Method Implementation

This example includes potential steps for an agency to consider when establishing a calibrated 

pavement markings nighttime visual inspection method. Agencies are encouraged to customize 

the plan to local conditions and agency practices. 

1. Using the MUTCD and the information in the “Getting Started” section of this appendix, 

determine which markings will be included in your agency’s method. If the agency 

chooses to create an inventory, the most critical information will be the location identifier 

and the type of markings (i.e., edge line, center line, and lane line) so that the inspector 

can document which markings need to be replaced. It is worth noting the presence of 

RRPMs since visual inspections of pavement markings supplemented with RRPMs can 

be difficult. The brightness of RRPMs in good condition is usually much greater than that 

of the pavement markings, and therefore it can be difficult to judge the pavement 

marking retroreflectivity. Other information, such as the type of pavement marking 

material, can be useful if the agency is using the information from the inspections for 

future planning.

2. Select a documentation technique to track/schedule replacement of specific markings. 

This tracking and scheduling of replacement markings can be a list, spreadsheet, or 

database and might also include maps or GIS components.

3. Establish calibration markings. 

a. The retroreflectivity levels of the calibration markings are checked before each 

cycle of inspections. Typically, calibration markings are higher than the MUTCD 
Calibrated Pavement Markings Nighttime Visual Inspection Method

July 2022 53

minimum level to allow time to schedule needed replacement of markings 

identified in the inspection before they reach the minimum level. 

b. The calibration markings include both yellow and white markings and are

positioned accordingly (e.g., for a two-lane, two-way roadway, white on the right 

and yellow on the left).

c. The calibration markings are located in an area without significant external 

ambient lighting (e.g. street or parking lot lighting) so that the visual calibration is 

not impacted by these light sources. A location central to the markings being 

inspected (especially the first night of a cycle of inspections) is helpful so that the 

inspector can come back and visually recalibrate during the night’s inspection if 

needed. 

d. If the calibration pavement markings are installed specifically for this purpose, the 

contractor or installer will need to make special provisions to apply pavement 

markings near the desired levels. This will take some trial and error because the 

levels will be much lower than typical new pavement markings. However, it can 

generally be achieved by controlling truck speed and bead load rates. If needed, 

retroreflectivity can be lowered by applying a clear coat of polyurethane, acrylic, 

or other similar product.

e. The calibration markings can be viewed in a static or dynamic condition. 

i. If the calibration markings are set up to be viewed in a static condition, the 

calibration markings should be at least 10 feet long and the inspection 

vehicle positioned 100 feet in advance of the calibration markings. This 

replicates the 30-meter geometry used in retroreflectometer measurements.

ii. If the calibration markings are to be used in a dynamic condition, they 

should be long enough to provide the inspector at least 15 seconds of 

viewing time to study the brightness of the marking. This means that the 

length of calibration markings to be used in dynamic conditions varies 

with the speed. The intended speed of the inspection vehicle during 

calibration can be used to calculate the length of calibration markings 

needed. If the agency has pavement markings on roads open to public 

travel that are known to be at or above the MUTCD specified minimum 

levels, these markings can be used as calibration markings. However, in 

this case, the calibration process is performed at the posted or operating 

speed, which might necessitate a significant length of calibration marking. 

For example, at 60 mph, calibrated markings at least one-quarter mile long 

are needed to provide enough viewing time for the inspector to calibrate 

his or her eyes.

4. Select the vehicle to be used for inspection. Any size vehicle can be used as long as it is 

also used in the calibration process. Check the vehicle to ensure that the low-beam 

headlamps are properly aligned prior to performing calibration or inspections (see Figure 

5 in the main body of this report).

5. Select inspection crew. This method is typically conducted using a two-person crew. 

While the driver focuses on the driving task, the inspector evaluates the pavement 
Calibrated Pavement Markings Nighttime Visual Inspection Method

July 2022 54

markings and records the appropriate information. Although the view of the pavement 

markings is not the same for the passenger as the driver, it is similar, and the safety of the 

inspection procedure is important. Therefore, the use of a two-person crew is a practical 

and safe way to conduct an inspection using this method. The observation is made 

through the windshield of the vehicle at the normal travel speed of the roadway using 

low-beam headlamps. 

• Note: An alternative to a two-person crew is to use one person with a tape 

recorder or mounted camcorder for recording notes. The retroreflectivity 

assessments need to be made by the inspector at the time of the inspection. Video 

recordings are not to be used later for determining the condition of the markings

because video technology is not yet proven to provide the necessary quality to be 

used in assessing retroreflectivity. 

6. Conduct inspector training. Agencies are encouraged to provide some form of training for 

pavement marking inspectors before they perform nighttime inspections despite the 

current lack of recognized training or certifications. Elements of the training might 

include:

a. Purpose and objectives of the inspection.

b. Critical inspection techniques and cautions for improper techniques.

c. Types of markings to evaluate.

d. When to conduct the inspection.

e. Documentation.

f. Safety.

g. Equipment.

h. Appropriate agency policies and procedures.

i. How to rate in-service markings using this method.

A helpful element of the training for this method is to have inspectors observe sample 

pavement markings at a variety of known retroreflectivity levels, including levels near 

the MUTCD minimum levels. This type of training provides the inspector experience

recognizing differences between various retroreflectivity levels. Inspectors benefit from 

training at night using the vehicle that will be used during the inspection.

7. Establish inspection routes. Where multiple retroreflectivity thresholds are used (e.g. for 

roads with speed limits 70 mph or higher), plan routes by separating higher-speed roads 

from lower-speed roads so that the inspector’s eyes are calibrated for the correct 

retroreflectivity threshold for the route. 

8. Perform the nighttime visual inspection. 

a. The ambient conditions must be dark—at least 30 minutes beyond sunset—and 

the condition of the pavement must be dry during the calibration and during the 

inspection. 

b. The inspector views the calibration markings from the vehicle to be used for the 

inspection before each night’s inspection begins. 

iii. For a static calibration, the inspector parks the inspection vehicle about 

100 feet in front of a designated part of the calibration markings (e.g. a 
Calibrated Pavement Markings Nighttime Visual Inspection Method

July 2022 55

specific broken line of an existing lane line or the center of a 10 foot 

portion) and commits to memory the appearance (i.e., brightness) of the 

calibrated markings from the seat he/she will be inspecting the markings. 

iv. For a dynamic calibration, the inspector determines an appropriate speed 

or range of speeds for the night’s inspection, calculates a 15 second 

viewing distance at that speed (e.g. 15 seconds ÷ 3600 second/hr × 50 mph 

× 5280 ft/mile = 1100 ft), and finds an appropriate reference point in the 

vehicle to assist in maintaining his/her focus at that distance. The driver 

then navigates the calibration markings at the appropriate speed while the 

inspector commits to memory the appearance (i.e., brightness) of the 

calibrated markings while focused at that distance. More than one pass of 

the calibration markings can be beneficial.

c. The driver navigates the planned inspection route while the inspector rates inservice markings adjacent to the vehicle, considering whether markings appear 

brighter than the calibration markings, nearly the same, or less bright. The 

inspector uses a dimmed14 light or a computer dimmed for nighttime viewing to 

take notes to avoid corrupting the inspection process by in-vehicle illumination 

that would impact proper viewing of the roadway and pavement markings.

9. Schedule markings to be replaced as needed using the inspector’s ratings. Determine how 

best to prioritize replacement based on ratings, upcoming projects, and weather 

conditions that limit striping seasons. 

10. Update the marking inventory as needed after restriping activities have occurred. 

11. Assess and update the calibration and inspection process as needed (e.g. recommended 

timeframe to borrow retroreflectometer so that calibrated markings can be measured and 

refreshed, if necessary, before the next inspection cycle). Consider if additional roadways 

and their markings need to be added.

Examples

Table B5 shows a hypothetical example of an inspection data collection sheet that could be used 

by inspectors. The sheet indicates the general location of the nighttime visual inspection, who 

conducted the inspection, what vehicle was used, and when the inspection occurred. Each row 

indicates a homogeneous roadway section in a specific travel direction. The inspector rates each 

section and records notes on each section as appropriate.

An inventory example is shown in Table B6. Each roadway to which the method applies would 

be included, although the example only shows a small sample. Field data such as evaluation 

dates and corresponding inspection ratings are used to update the inventory. Planned restriping 

activities or the next anticipated evaluation date would be helpful to include as well. The 

inventory can be organized according to a planned inspection route to make implementing the 

14 A red dimmed light is preferable over a white light to reduce the impact on the observer’s night vision.
Calibrated Pavement Markings Nighttime Visual Inspection Method

July 2022 56

method easier. The spreadsheet could be supplemented or replaced with a GIS database or map 

system.
Calibrated Pavement Markings Nighttime Visual Inspection Method

July 2022 57

Table B5. Example survey data collection sheet for calibrated pavement markings nighttime visual inspection.

Pavement Marking Retroreflectivity Inspection Report

Inspection Date: 4/11/2021 Agency/Location: Lincoln County, north of Rum River

Calibration Time: 9:00 pm Inspection Time: 9:45 pm–1:00 am Calibration Marking Measurement Date: 4/1/2021

Inspector: L. Nguyen Inspector Age: 48 Calibration Marking 

Levels

15: 

White: 113 mcd/m2/lux

Driver: D. Wright Vehicle Number: 11 Yellow: 106 mcd/m2/lux

Roadway Section 

Identifier Limits Travel Direction

MARKING RATING16

Notes Center Line 

or Left Edge 

Line (yellow)

Lane Line 

(white)

Right Edge 

Line 

(white)

CR 11 3A CL to MP4 EB P N/A17 P

CR 11 3B MP4 to MP7 EB P N/A P

CR 11 3C MP7 to MP12 EB M N/A M

CR 11 3D MP12 to I-35 EB P N/A M RPMs present on center line

CR 11 3A CL to MP4 WB M N/A P

CR 11 3B MP4 to MP7 WB M N/A P

CR 11 3C MP7 to MP12 WB M N/A M

CR 11 3D MP12 to I-35 WB P N/A M RPMs present on center line

Main St. N/A All NB F F F Right edge captured on 2nd pass

Main St. N/A All SB F F F Right edge captured on 2nd pass

Green Ln. N/A All NB M N/A M Markings are dirty

Green Ln. N/A All SB M N/A M Markings are dirty

CR 6 N/A All SB M N/A N/A Yellow marking color is fading

CR 6 N/A All NB M N/A N/A Close to failing

 

15 Measured retroreflectivity of calibration markings.

16 Ratings: P = Pass, M = Marginal, F = Fail.

17 Not applicable because marking type was not present (e.g. no lane lines on two-lane, two-way road or no edge lines on two-lane road).
Calibrated Pavement Markings Nighttime Visual Inspection Method

July 2022 58

Table B6. Spreadsheet example of roadway database for calibrated pavement markings nighttime visual inspection.

Road Name (Segment Identification18

)

Segment Length and LimitsFunctional ClassificationTraffic Volume (ADT)Speed Limit (mph)Pavement SurfacePavement Marking MaterialMarking ThicknessReflective OpticsWinter MaintenanceLine Type(s)19Installation DateScheduled for Restriping?Previous Inspection Rating20and Date Evaluated21Notes22

Main 

Street

2.6 miles 

(Justin 

Blvd to 

14th Ave)

Minor 

Arterial 11,000 50 asphalt water-based paint 15 mils

AASHTO 

M247

Type I

Low EL, CL, 

LL 4/14/20 Yes

All Very 

Good, 

March 2020

Main 

Street

1.7 miles 

(14th Ave 

to city 

limit)

Minor 

Arterial 7,200 50 asphalt water-based paint 15 mils

AASHTO 

M247

Type I

Low EL, CL 4/14/20 May 

2021 None

University 

Drive

4.2 miles 

(Rte 1 to 

Rte 18)

Major 

Arterial 17,000 40 asphalt spray thermoplastic 90 mils

Double 

Drop Type 

II and III

Low EL, CL, 

LL 5/18/19 No

White 

Marginal, 

Yellow Fail 

March 2020

Has overhead 

lighting, but keep 

on monitoring 

program

14th Ave

0.5 miles 

(Main St 

to Jay St)

Local 5,500 35 asphalt water-based 

paint 15 mils

AASHTO 

M247

Type I

None CL 8/14/20 Yes

White 

Acceptable, 

Yellow 

Marginal 

March 2020

Include in method 

due to expected 

increase in ADT

Replace before 

winter

... ... ... ... ... ... ... ... ... ... ... ... ... ...

... ... ... ... ... ... ... ... ... ... ... ... ... ...

... ... ... ... ... ... ... ... ... ... ... ... ... ...

18 Unique road segment identifier (if used by agency).

19 CL = center line, EL = edge line, LL = lane line.

20 Ratings: Excellent, Very good, Acceptable, Marginal, Fail.

21 Link inspection data sheets to the database.

22 Include notable site characteristics and other notes.
Service Life Based on Historical Data Method

July 2022 59

Method Development: Service Life Based on Historical Data 

Method Definition

In this method, an agency documents pavement marking installation dates and, using historical 

retroreflectivity data and/or research results, develops a schedule for replacing the markings

before they reach their end of service life. This schedule is designed to maintain the pavement 

marking retroreflectivity at or above the MUTCD minimum retroreflectivity levels. Using this 

method, agencies can set pavement marking replacement schedules for markings with similar 

characteristics in similar conditions. 

Method Needs

To successfully implement a maintenance method that uses marking service life based on 

historical data, the following will be needed: 

• Roadway sections and markings to be included in the maintenance method.

• Historical (or research) data on how long pavement markings materials used by the 

agency last under similar weather and traffic conditions before reaching a predetermined 

retroreflectivity level.

• Pavement marking information.

The historic service life data is unique to this maintenance method. Having reliable service life 

information applicable to local conditions and the material type and thickness used might be a 

concern when selecting this method. Variations in weather and marking installation quality also 

impact the expected service life of the markings and need to be taken into consideration. 

Potential sources of this data include state or other agency databases, marking guidance, or 

research reports. Another way to obtain accurate service life data is to use the monitored 

markings service life method or the measured markings method for a few years, then switch to 

the historical service life method when enough data has been collected to accurately predict 

service life. However, if the agency changes marking materials, another round of monitoring or 

measuring might be needed to obtain historical service life for the new materials. 

Method Implementation

This example includes potential steps for an agency to consider when establishing a service life 

based on the historical data maintenance method for pavement marking retroreflectivity. 

Agencies are encouraged to customize the method to local conditions and agency practices. 

1. Using the MUTCD and the information in the “Getting Started” section of this appendix, 

determine which markings will be included in your agency’s method. Regardless of 

whether or not the agency chooses to develop an inventory, for this method, it is essential 

to have records of when specific markings were installed. Particularly useful information 

in an inventory would include installation location, date, marking type, pavement surface, 

traffic volume, and expected weather conditions. Other pavement marking and roadway 

specific information will also be important to determining the appropriate service life. 

Marking service life is generally dependent on:

a. Pavement marking type (e.g., binder, thickness, inlay, and optics).

b. Pavement surface.
Service Life Based on Historical Data Method

July 2022 60

c. Use/frequency of snowplow operations.

d. Traffic volumes.

e. Climate.

2. Select a documentation technique to track and schedule the replacement of specific 

markings. This tracking and scheduling of replacement markings can be a list, 

spreadsheet, or database and might also include maps or GIS components.

3. Document historical or research data on retroreflectivity levels and marking service life 

for conditions and materials similar to those under your agency’s jurisdiction.

a. Use marking and roadway characteristic data to estimate the marking service life 

as accurately as possible for the marking materials used and roadway conditions.

b. Use the expected service life from the historical or research data to determine 

when markings of each type, color, etc. will likely reach the appropriate MUTCD 

minimum level or higher threshold established by the agency. Chapter 6 of this 

report provides some general ranges of expected marking service life; however, 

local conditions will determine expected service life in your method. If adequate 

expected service life data are not available for local conditions, consider using 

another maintenance method until adequate data are established. 

4. Develop groupings that have the same marking materials on roadways with similar 

characteristics. These groupings will all use the same expected service life and will be 

restriped at the same intervals. That does not necessarily mean all roadways with 

markings in the same grouping will be striped the same year. The installation of the 

markings could be staggered initially to spread out initial and subsequent restriping costs. 

5. Review installation dates to determine the age of each group of markings and compare to 

the expected service life determined based on historical or research data.

6. Schedule markings to be replaced before they reach the end of their service life. 

Determine how best to prioritize replacement based on years in service, upcoming 

projects, and weather conditions that limit striping seasons. 

7. Update the marking inventory as needed after restriping activities have occurred (e.g. to 

indicate date markings were replaced and type of material used). Update roadway 

groupings if new marking materials were used or if conditions have changed.

8. Assess and update the maintenance method and supporting information, as necessary. 

Consider if additional roadways and their markings will be added. Revise service life 

information and restriping schedules as new historical/research information becomes 

available.

Examples

Table B7 shows a hypothetical example of the type of historical data an agency could use in 

developing a catalog of pavement marking service life data for use with this method. The data 

provided are hypothetical; please do not use for purposes beyond this example. The service life 

for a particular marking under your local conditions might be longer or shorter than the times 

listed in the table for the conditions described. 

An inventory example is shown in Table B8. Each roadway to which the method applies would 

be included, although the example only shows a small sample. Roadways with similar 
Service Life Based on Historical Data Method

July 2022 61

characteristics and similar markings can be grouped together to make identifying the expected 

service life easier. Planned restriping activities are included to update the inventory. The

spreadsheet could be supplemented or replaced with a GIS database or map system.
Service Life Based on Historical Data Method

July 2022 62

Table B7. Hypothetical example of expected pavement marking service life (Do not use these values—example only).

Historical Data for Pavement Marking Service Life (Clay County)

Service Life 

Grouping

Pavement Marking 

Type

Pavement 

Surface ADT range

Use/Frequency 

of Snowplow 

Operations

Service Life to 

reach RL

50 mcd/m2/lux

Data Source/ Date Notes

Paint, Asphalt 1 Water-based paint, 

15 mil, Type I beads Asphalt 3,000–5,000 None Yellow—18 months Route 5 Test Area, Clay County: 5/2017 

No data for white, expected 

to be equal to or greater 

than yellow. Source data 

from local testing.

Paint, Asphalt 2 Water-based paint, 

15 mil, Type I beads Asphalt 5,000–8,000 None White—16 monthsYellow—16 months

Route 5 Test Area, 

Clay County: 5/2017

Source data from local 

testing.

Paint, Asphalt 3 Water-based paint, 

15 mil, Type I beads Asphalt 10,000–20,000 None White—14 monthsYellow—12 months

Durango Parkway 

Monitored Markings, 

Clay County: 7/2016 

Source data from past 

monitored markings area.

Paint, Asphalt 4 Water-based paint, 

15 mil, Type I beads Asphalt 5,000–8,000 Medium, 5-10 times/year

White—12 months

Yellow—12 months

Mountain Pass Test 

Area, Union County: 

5/2018 

Adjacent county with 

results on snow plowed 

roads.

Paint, Concrete 1 Water-based paint, 

15 mil, Type I beads Concrete 15,000–25,000 None White—12 monthsYellow—12 months

Northern Blvd 

Monitored Markings, 

Clay County: 9/2016

Source data from past 

monitored markings area.

Thermoplastic, 

Asphalt 1

Thermoplastic, 90 

mil, double drop 

Type II and III 

beads

Asphalt 6,000–8,000 None White—48 months

Yellow—44 months

Main Street 

Monitored Markings, 

Clay County: 8/2019

Source data from past 

monitored markings area.

Thermoplastic, 

Asphalt 2

Thermoplastic, 90 

mil, double drop 

Type II and III 

beads

Asphalt 10,000–

20,000 None White—42 monthsYellow—40 months

State Research Report 

B-1141: 8/2017

Apply state level data to 

local roads with similar 

markings and traffic 

conditions.

Thermoplastic, 

Asphalt 3

Thermoplastic, 90 

mil, double drop 

Type II and III 

beads

Asphalt 20,000–

30,000

Low, 3-5 

times/year

White—36 months

Yellow—36 months

State Research Report 

B-1141: 8/2017

Apply state level data to 

local roads with similar 

markings and traffic 

conditions.

Thermoplastic, 

Concrete 1

Thermoplastic, 90 

mil, double drop 

Type II and III 

beads

Concrete 30,000–

40,000 None White—36 monthsYellow—36 months

State Research Report 

B-1141: 8/2017

Apply state level data to 

local roads with similar 

markings and traffic 

conditions.
Service Life Based on Historical Data Method

July 2022 63

Table B8. Spreadsheet example of roadway database for service life based on historical data (hypothetical data).

Road Name (Segment Identification23

)

Segment Length and LimitsFunctional ClassificationTraffic Volume (ADT)Speed Limit (mph)Pavement SurfacePavement Marking MaterialMarking ThicknessReflective OpticsWinter MaintenanceLine Type(s)24Installation DateExpected Service Life25 (Service Life Grouping)Expected Replace by Date26Scheduled for Restriping27Notes28

Main 

Street

2.6 miles 

(Justin 

Blvd to 14th

Ave)

Minor 

Arterial 11,000 50 asphalt water-based paint 15 mils

AASHTO 

M247

Type I

Low EL, 

CL, LL 4/14/20

W29—12 

months,

Y—12 months 

Paint Asphalt 3

4/14/21 Spring 

contract

Main 

Street

1.7 miles 

(14th Ave to 

city limit)

Minor 

Arterial 7,200 50 asphalt water-based paint 15 mils

AASHTO 

M247

Type I

Low EL, CL 4/14/20

W—12 months,

Y—12 months 

Paint Asphalt 4

4/14/21 Spring 

contract

University 

Drive

4.2 miles 

(Rte 1 to 

Rte 18)

Major 

Arterial 17,000 40 asphalt spray thermoplastic 90 mils

Double 

Drop Type 

II and III

Low EL, 

CL, LL 5/18/19

W—36 months,

Y—36 months 

Thermoplastic 

Asphalt 3

5/18/22 No

Has overhead 

lighting, but keep 

on monitoring 

program

14th Ave

0.5 miles 

(Main St to 

Jay St)

Local 5,500 35 asphalt water-based 

paint 15 mils

AASHTO 

M247

Type I

None CL 8/14/20 Y—16 months 

Paint Asphalt 2 12/14/21 Fall contract

Include in method 

due to expected 

increase in ADT

Replace before 

winter

... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ...

... ... ... ... ... ... ... ... ... ... ... ... ... ... ... ...

23 Unique road segment identifier (if used by agency).

24 CL = center line, EL = edge line, LL = lane line.

25 Expected service life based off historic data of similar markings on similar road type and which service life grouping category (see Table B2).

26 When are the markings expected to be replaced based on installation date and expected service life?

27 Has the section been scheduled for restriping?

28 Include notable site characteristics, if section is being used to gather future expected service life data, and other notes.

29 W indicates white marking (i.e. lane line or right edge line), and Y indicates yellow marking (i.e. center line or left edge line on divided road).
Service Life Based on Monitored Markings Method

July 2022 64

Method Development: Service Life Based on Monitored Markings

Method Definition

In this method, an agency documents pavement marking installation dates and periodically 

monitors the retroreflectivity of a representative sample of those markings to track their 

durability. The agency uses these monitored markings to represent a larger group of markings

with similar characteristics in similar conditions. When each group of the monitored markings 

degrade and approach the MUTCD minimum levels, the markings have reached their end of 

service life, and the entire group of markings (both the monitored markings and the larger group

of pavement markings they represent) are scheduled for replacement before they are expected to 

reach the minimum retroreflectivity levels. This is an alternative method for agencies that want 

to use a service life method but do not have historical data or research supporting service life 

estimates for their region’s specific conditions (i.e., their in-service life before reaching the 

appropriate MUTCD minimum level or higher agency established threshold).

Method Needs

To successfully implement a maintenance method that uses service life based on monitored 

markings, the following will be needed:

• Roadway sections and markings to be included in the maintenance method.

• Sets of markings to serve as the monitored markings that include a reasonable range of 

key factors for the larger group they represent.

• Pavement marking information.

Having a representative sample of markings is critical to this method. Considering material type 

and thickness, as well as roadway conditions, will be important to determining appropriate 

factors for grouping the markings. Variations in weather and marking installation quality also 

impact the expected service life but are typically not an issue unless they are significantly 

different between the monitored markings and the larger sample they represent (e.g. markings on 

a mountain pass are likely subjected to more snow plow passes than those in a valley).

Method Implementation

This example includes potential steps for an agency to consider when establishing a service life 

based on the monitored markings maintenance method for pavement marking retroreflectivity. 

Agencies are encouraged to customize the method to local conditions and agency practices. 

1. Using the MUTCD and the information in the “Getting Started” section of this appendix, 

determine which markings will be included in your agency’s method. Whether or not the 

agency has an inventory, it is essential to be able to associate each marking within the 

method to the similar monitored markings that represent it. An inventory is particularly 

useful to assist in this association. For this method, key information includes:

a. Pavement marking type (e.g., binder, thickness, inlay, and optics).

b. Pavement surface.

c. Use/frequency of snowplow operations.
Service Life Based on Monitored Markings Method

July 2022 65

d. Climate.

e. Traffic volumes.

f. Installation date.

2. Select a documentation technique to track and schedule the replacement of specific 

markings. This tracking and scheduling of replacement markings can be a list, 

spreadsheet, or database and might also include maps or GIS components.

3. Develop groupings that have the same marking materials on roadways with similar 

characteristics. These groupings will all use the same monitored markings against which 

to compare. The trending retroreflectivity levels from the monitored markings will be 

used to schedule pavement marking replacements. 

4. Establish the sets of markings to use as the monitored markings and record their 

retroreflectivity levels. 

a. The preferred way to monitor markings is the measured retroreflectivity method. 

However, an agency could instead assess the monitored markings using either the 

calibrated pavement markings nighttime visual inspection method or the 

consistent parameters nighttime visual inspection method. Please refer to the 

specific chapters of the report and other sections of this appendix for more 

information on those methods.

b. Ensure the length of the roadway sections with the monitored markings is long 

enough and in enough different locations to provide a statistical representation of 

the larger group of markings they are meant to represent. A larger sample of 

monitored markings might be appropriate if one of the nighttime visual inspection 

methods are used, due to the less precise nature of this method. 

c. Determine how frequently the retroreflectivity levels of the monitored markings 

need to be assessed to ensure the markings are scheduled to be replaced prior to 

reaching the MUTCD minimum levels.

d. Determine the sampling procedure for the monitored marking evaluation. Collect 

and record an adequate number of retroreflectivity readings (see ASTM D 7578) 

if measuring retroreflectivity. If using a nighttime visual inspection method, 

consider multiple recorded observations along the length of the monitored section 

to achieve a representative sample. 

e. Conduct the inspection of the monitored markings.

5. Schedule markings in both the monitored sections and the larger group of markings they 

represent to be replaced before the associated monitored markings reach the appropriate 

MUTCD minimum level or the higher agency established threshold. Determine how best 

to prioritize replacement based on years in service, upcoming projects, and weather 

conditions that limit striping seasons.

6. Update the marking inventory as needed after restriping activities have occurred (e.g. to 

indicate date markings were replaced and type of material used). Update roadway 

groupings if new marking materials were used or if conditions have changed.

7. Assess and update the maintenance method and supporting information, as necessary. 

Consider if additional roadways and their markings need to be added. 
Service Life Based on Monitored Markings Method

July 2022 66

Examples

Figure B3 shows an example of a map that could be developed by an agency to depict the 

location of the monitored markings and the larger group of markings with similar conditions that 

the monitored markings represent. It depicts a single pavement marking type (paint) and multiple 

installation years (2019 and 2020). Each year has its own set of installations and monitored 

markings. Based on retroreflectivity of the monitored markings, the entire group of markings 

(i.e., both monitored and the larger group they represent) are restriped before the monitored 

markings reach the appropriate MUTCD minimum level or the higher agency threshold. 

Additional maps or different colors or patterns on the map would be needed to represent other 

marking types, installation years, or different conditions.

Figure B3. Diagram. Example of monitored markings map.

An inventory example is shown in Table B9. The example only includes one group with similar 

pavement, marking, and volume considerations. Consider additional groups with separate 

monitored marking sections for different volumes, pavement types, marking material properties, 

or winter maintenance conditions. The other groups could be listed in separate tables with their 

own sets of monitored marking sections. All roadway sections within a group need to have 

similar characteristics and are restriped at the same time based on the retroreflectivity of the 

monitored markings so planned restriping activities can be done for each group rather than each 

segment. Evaluation is only required for the monitored markings, so that column will only be

needed for the monitored segments. The spreadsheet could be supplemented or replaced with a 

GIS database or map system. Each roadway with markings that meet the requirements of the rule 

needs to be included. 
Service Life Based on Monitored Markings Method

July 2022 67

Table B9. Spreadsheet example of roadway database for service life based on monitored markings.

Group 1: Waterborne Paint on Bituminous Surface with Traffic Volumes between 

5,000 and 15,000 ADT and Speed Limits under 60 mph (Agency threshold = 75).

Restriping Scheduled? No, measurements in monitored 

segments indicate this group will last until Spring.

Road/Segment Identification30Segment Length and LimitsMonitored segment? (if so, date measured)Functional ClassificationTraffic Volume (ADT)Speed Limit (mph)Winter MaintenanceBinder Thickness (mils)Reflective Optics (AASHTO M247)Installation DateLine Type(s)31Monitoring Results32Next Date to MonitorNotes33

Main St. 

Extension, Clay

County

2.5 miles

(June Ln to Green 

County Line)

Yes

11/18/19 Local 9,500 45 None 15 Type I 5/14/19

CL

EL

LL

94 (Y34)

114 (W)

103 (W)

3/18/20 Monitored Marking 

Section

Route 45 

(Control Section 

1-66)

6.2 miles (Grand 

Blvd to US 50) No Minor Arterial 11,000 50 None 15 Type I 5/17/19 CLEL

Route 45 11.4 miles (US 50 to 

Mason County Line) No Minor Arterial 7,000 55 None 15 Type I 5/17/19 CLEL

Balcones Drive, 

Clay County 

4.2 miles (Rte 45 to 

Rte 66) No Local 12,000 40 None 15 Type I 4/28/19 ELLL

Overhead lighting, but keep 

on retro monitoring 

program

Grand Blvd 3.7 miles (Main St to 

Foothills Rd)

Yes

11/18/19

Minor 

Arterial 12,000 40 None 15 Type I 5/14/19 ELLL

97 (Y)

127 (W) 3/18/20

Monitored Marking 

Section

Divided by raised median

... ... ... ... ... ... ... ... ... ... ... ... ... ...

... ... ... ... ... ... ... ... ... ... ... ... ... ...

30 Unique road segment identifier (if used by agency).

31 CL = center line, EL = edge line, LL = lane line. 

32 Average of measured retroreflectivity for each line type. Only applies to monitored segments—leave other segments blank.

33 Include notable site characteristics, if section is being used to gather future expected service life data, and other notes.

34 Y indicates yellow marking (i.e. center line or left edge line on divided road), and W indicates white marking (i.e. lane line or right edge line).
For More Information

www.fhwa.dot.gov/retro