Safety Edge SM

Demonstration Project 

Turner, Maine 

Field Report 

June 15, 2011 
FOREWORD 

The purpose of this field report is to provide a summary of observations made during the hot 

mix asphalt (HMA) Safety EdgeSM project located in Androscoggin County on State Route 

(SR) 117 in Turner, Maine, just east of the intersection between SR 117 and SR 4. These 

observations and data are to be used with similar information from other Safety EdgeSM

projects to facilitate the development of standards and guidance for Safety EdgeSM

construction and long-term performance. 

This report is a summary of the observations and field data measured during construction on 

August 11 and 12, 2010 to evaluate the use of the Advant-Edger, TransTech Shoulder Wedge 

Maker, and TransTech Notched Wedge Joint Maker. Observations and data were collected to 

evaluate the slope and density of the Safety EdgeSM, recommend design adjustments, and 

identify benefits and complications with the use of the edge device. 
ii

1. Report No. 

15. Supplementary Notes 

 Contracting Officer’s Technical Representative: Byron Lord and Mary Huie

Contracting Officer’s Technical Manager: Andy Mergenmeier

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

3. Title and Subtitle 

Safety EdgeSM Demonstration Project, 

Turner, Maine 

5. Report Date 

 June 15, 2011 

6. Performing Organization Code 

7. Authors 

Harold Von Quintus and Jagannath Mallela 

8. Performing Organization Report No. 

9. Performing Organization Name and Address 

 Applied Research Associates, Inc. 

 100 Trade Centre Drive, Suite 200 

 Champaign, IL 61820 

10. Work Unit No. 

11. Contract or Grant No. 

12. Sponsoring Agency Name and Address 

 Office of Infrastructure 

 Federal Highway Administration 

 1200 New Jersey Avenue, SE 

 Washington, DC 20590

13. Type of Report and Period Covered 

 Field Report 

 August 2010 – June 2011

14. Sponsoring Agency Code 

16. Abstract 

In a coordinated effort with highway authorities and industry leaders, the Every Day Counts initiative serves as a catalyst to 

identify and promote cost effective innovations to bring about rapid change to increase safety of our nations highway 

system, decrease project delivery time, and protect our environment. The Safety EdgeSM concept is an example of one such 

initiative in which the edge of the road is beveled during construction for the purpose of helping drivers who migrate off the 

roadways to more easily return to the road without over correcting and running into the path of oncoming traffic or running 

off the other side of the roadway. 

This field report documents the observations made on the construction of the Safety EdgeSM on a two lane highway hot mix 

asphalt (HMA) overlay project in Turner, Maine. The Advant-Edger, TransTech Shoulder Wedge Maker, and TransTech 

Notched Wedge Joint Maker devices were demonstrated during this project. Details regarding the performance of the 

devices along with the shape and physical properties of the finished Safety EdgeSM are presented for the purpose of 

understanding what processes and techniques were most successful in forming the Safety EdgeSM. 

The findings from this overlay project and other similar ongoing projects form the basis for understanding the construction 

process and material performance necessary to bring this innovation into common highway practice and make our Nation’s 

highways safer. 

17. Key Words 

Safety EdgeSM, Slope, HMA, Advant-Edger, 

TransTech Shoulder Wedge Maker, TransTech 

Notched Wedge Joint Maker. 

18. Distribution Statement 

No restriction. 

19. Security Classif.(of this report) 

Unclassified 

20. Security Classif. (of this page) 

Unclassified 

21. No. of Pages 

27 

22. Price 

Form DOT F 1700.7 (8-72)
iii

SI* (MODERN METRIC) CONVERSION FACTORS 

APPROXIMATE CONVERSIONS TO SI UNITS 

Symbol When You Know Multiply By To Find Symbol 

LENGTH 

(none) mil 25.4 micrometers μm

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

ft2square feet 0.093 square meters m

2

yd2square yards 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 millimeters mL 

gal gallons 3.785 liters L 

ft3cubic feet 0.028 cubic meters m

3

yd3cubic 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) 

°F Fahrenheit 5 (F-32)/9 

or (F-32)/1.8 

Celsius °C

ILLUMINATION 

fc foot-candles 10.76 lux lx

fl foot-Lamberts 3.426 candela per square meter cd/m2

FORCE and PRESSURE or STRESS 

lbf poundforce 4.45 Newtons N 

lbf/in2 (psi) poundforce per square inch 6.89 kiloPascals kPa 

k/in2 (ksi) kips per square inch 6.89 megaPascals MPa 

DENSITY 

lb/ft3 (pcf) pounds per cubic foot 16.02 kilograms per cubic meter kg/m3

APPROXIMATE CONVERSIONS FROM SI UNITS 

Symbol When You Know Multiply By To Find Symbol 

LENGTH

μm micrometers 0.039 mil (none) 

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

km2square 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 

°C Celsius 1.8C+32 Fahrenheit °F

ILLUMINATION 

lx lux 0.0929 foot-candles fc

cd/m2candela per square meter 0.2919 foot-Lamberts fl

FORCE and PRESSURE or STRESS 

N Newtons 0.225 poundforce lbf 

kPA kiloPascals 0.145 poundforce per square inch lbf/in2 (psi) 

MPa megaPascals 0.145 kips per square inch k/in2 (ksi) 

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

2003) 
iv

Table of Contents 

Topic Page 

FOREWORD................................................................................................................................. 1

SUMMARY OF OBSERVATIONS............................................................................................ 1

Overall Opinion of the Safety EdgeSM ..................................................................................... 1

Slope of Safety EdgeSM ............................................................................................................ 1

Placement ................................................................................................................................ 1

Compaction ............................................................................................................................. 1

Shoulder Construction ............................................................................................................ 2

FIELD EVALUATION OF HMA OVERLAY WITH SAFETY EDGESM ............................ 3

INTRODUCTION ............................................................................................................................... 3

PAVEMENT STRUCTURE AND PROJECT CONDITIONS .................................................................... 3

FIELD EVALUATION TESTS ............................................................................................................ 7

Slope Measurements ............................................................................................................... 9

Cores ..................................................................................................................................... 11

PQI Percent Compaction (Density) Results.......................................................................... 12

OBSERVATIONS MADE DURING PAVING WITH THE SAFETY EDGESM ........................................ 14

Safety EdgeSM for Both HMA Lifts........................................................................................ 14

Transition from Safety EdgeSM to non-Safety EdgeSM........................................................... 16

Centerline Joint Using the TransTech Notched Wedge Joint Maker.................................... 17

Placement/Paving Operations .............................................................................................. 19

Compaction Operations ........................................................................................................ 22

FINDINGS AND CONCLUSIONS ...................................................................................................... 26

APPENDIX A. DATA TABLES FROM FIELD MEASUREMENTS ............................... A-1
1

SUMMARY OF OBSERVATIONS 

This section of the field report provides a summary and listing of important observations 

made during the paving operations, interview with paving personnel and findings from the 

field measurements taken during paving that are expected to have a significant impact on the 

performance of the Safety EdgeSM. 

Overall Opinion of the Safety EdgeSM

The Safety EdgeSM did not have a detrimental impact on the agency’s paving operation 

during mainline paving. Some issues, however, were encountered that need to be resolved. 

These are noted in some of the following bullet items. 

Slope of Safety EdgeSM

 The average slope of the Safety EdgeSM using the Advant Edger Safety EdgeSM device 

was found to be 54°. None of the 13 measurements were less than 45° and only one 

measurement was less than 50°. 

 The average slope of the Safety EdgeSM using the TransTech Shoulder Wedge Maker was 

found to be 45°. Eight of the 21 measurements were less than 40° and two measurements 

were between 45° and 50°. 

 The centerline joint made using the TransTech Notched Wedge Joint Maker had an 

average slope of 19o. 

 Although both the Advant-Edger and TransTech Shoulder Wedge Maker devices 

produced an edge with a slope of 30o immediately behind the screed, because of the 

difference in device pressure and shape, the slope of the Safety EdgeSM made with the 

Advant-Edger device increased to an average of 54o and that of the Safety EdgeSM made 

with the TransTech device increased to an average of 45o after rolling. It should be noted 

that the HMA mix for the surface wearing course was “normal” and not too tender or too 

stiff, and using a mix with a different level of stiffness could result in different values. 

Placement 

 The Safety EdgeSM was formed using the Advant-Edger and TransTech Shoulder Wedge 

Maker which were properly bolted to the screed of the paver. Construction personnel 

suggested putting a sleeve around the Safety EdgeSM spring to keep HMA material out of 

this area so it does not get into the threads and make it difficult to adjust the Safety 

EdgeSM vertically. They also suggested that adding vibration to the device would 

probably make it better. 

Compaction 

 Compaction was performed using three rollers (a breakdown roller with 6 to 9 passes, an 

intermediate roller with 12+ passes, and a finish roller with 6 passes). 
2

 During the paving on August 11, the contractor made 9 passes using the breakdown roller 

for both the section paved with the Advant-Edger and the section paved without a Safety 

EdgeSM device. During the paving on August 12, the HMA was pushing, shoving, and 

tearing under the breakdown roller about 500 ft after paving started. It appeared to be a 

classic “tender zone” problem. The contractor reduced the number of the breakdown 

roller passes from 9 to 6 for the section paved with the TransTech Shoulder Wedge 

Maker. 

 The HMA mix density (and percent compaction) was slightly higher and the air voids 

slightly lower adjacent to the edge of the mat for the Safety EdgeSM sections in 

comparison to the non-Safety EdgeSM section based on core data. Thus, the Safety 

EdgeSM was believed to have a confining effect on rolling an unconfined edge condition. 

This observation is considered a benefit to the use of the Safety EdgeSM. However this 

was not corroborated with the PQI data, which showed no statistical difference between 

the Safety EdgeSM SM

Percent compaction of the HMA mat interior averaged 93% while percent compaction 

near the Safety EdgeSM and the non-Safety EdgeSM averaged around 84%, based on 

adjusted PQI data. The percent compaction near the centerline notched wedge joint was 

around 93% (after paving both lanes). 

sections and the non-Safety Edge section. 



Shoulder Construction 

 Type D aggregate (same as beneath the HMA layers and the foreslope) was planned to be 

used for the backing material. Placement of the backing material was not observed. 

This project presents the opportunity to evaluate long-term performance in terms of 

maintenance efforts and life cycle cost of the Safety EdgeSM. 
3

FIELD EVALUATION OF HMA OVERLAY WITH SAFETY EDGESM

Introduction 

A series of field tests were carried out to assess the placement and condition of the HMA 

overlay along SR 117 (Turner Center Road), near Turner, Maine, with and without the use of 

the Safety EdgeSM device. The purpose of this field study was to evaluate the quality of the 

in-place HMA material and Safety EdgeSM by investigating the following: 

 Correct use of the Safety EdgeSM devices during paving. 

 Safety EdgeSM versus non-Safety EdgeSM portions of project. 

 Slope of the Safety EdgeSM. 

The paving contractor (RC & Sons Paving) used the Advant-Edger (attached to the screed) 

on August 11 on the southbound lane and TransTech Shoulder Wedge Maker (attached to the 

screed) on August 12, on the northbound lane. The short section without Safety EdgeSM was 

at end of day on August 11, in the southbound lane. The paving contractor also used the 

TransTech Notched Wedge Joint Maker attached to the screed along the centerline for the 

entire length of the project (it is possible that it can be adjusted and used to make a Safety 

EdgeSM).

The project was located 12 miles north of Auburn, Maine. The 2.339 mile project began at 

station 347+00 on SR 117 (Turner Center Rd.), about 200 ft east/north of the intersection of 

SR 117 and SR 4 in Turner and extends east/north to station 470+50 near the Turner Center 

(intersection of Upper St., Center Bridge Rd., Cobb Rd., N Parish Rd. [route 117], and 

Turner Center Rd. [SR 117]), as shown in Figure 1. The speed limit is 25 mph for west/south 

half of the project (near the town of Turner) and 45 mph for east/north half of the project. 

MaineDOT personnel indicated that the 45 mph speed limit would be dropped to 40 mph at 

the conclusion of the project. 

Pavement Structure and Project Conditions 

The project consisted of reconstruction by milling the existing asphalt pavement, placing a 

variable depth (typically 18 inches) Type D aggregate for grade improvement, followed by 

placement of a 3 inch lift of a 19 mm HMA base course and a 2 inch lift of a 12.5 mm HMA

wearing course. This two-lane two-way roadway had 11 ft travel lanes with 3 ft shoulders. 

Figure 2 provides a general view of the 5 inch HMA layers, and typical cross section of the 

pavement. 

The Safety EdgeSM was incorporated into the project after it was awarded and no work order

was executed for the purpose. Thus there are no contract documents related to the Safety 

EdgeSM. The contractor was paid by ton of HMA at contract bid amount. 

The ditches along the edge of the pavement ranged from shallow or almost level with the 

existing pavement to moderately deep (refer to Figure 2 and Figure 3). Shoulder backing 
4

material is Type D aggregate, which is the same material as that beneath the HMA and on the 

foreslopes from the HMA to the ditch line. The specifications call for placing the material in 

8 inch maximum lift thickness, adding water, and compacting. The shoulder is shaped to the 

ditch at a slope of 3:1 (refer to Figure 3). Some locations have topsoil over the Type D 

aggregate; the specifications require contractor to obtain 90 percent growth of vegetation on 

the foreslope. 

Safety EdgeSM project near Turner, ME in Androscoggin County. 

Project starts 200 ft east/north of the intersection of SR 117 and SR 4 in Turner and extends 

east/north to Turner Center (intersection of Upper St., Center Bridge Rd., Cobb Rd., N 

Parish Rd. [ SR 117], and Turner Center Rd. [SR 117]).

Project ends at 

Turner Center 

Project starts east 

of intersection. 

Figure 1. Location of Site 
5

Planned 1.5 inch HMA 9.5 mm Overlay 

Existing HMA Pavement; Surface Milled 1.5 inches 

Prior to Overlay 

Existing shoulder trenched 2-foot wide to place 6 inches of 19 

mm HMA base for widening both sides of roadway for placing 

rumble strip and an edge strip on both sides of roadway. 

24-Foot Roadway Width 

9.5 HMA Overlay, 1.5 inches 

planned thickness; roadway 

width over bridge is 22 feet. 

Thin HMA leveling course 

placed in selected areas along

the roadway, after milling. 

Figure 2. 9.5 mm HMA overlay already placed in one direction and the thin leveling layer 

placed in opposite direction after milling but prior to overlay placement. 
6

The shoulder backing 

material foreslope is 

shaped to the ditch at a 

slope of 3:1 at most 

locations. The ditches 

were shallow or almost 

level with pavement at

other locations. 

Shoulder backing 

material is Type D 

aggregate, which is the 

same material as that 

beneath the HMA. 

Some locations have 

topsoil over the Type D 

aggregate.

Figure 3. Localized area with deep ditches adjacent to the pavement. 

At the time of the site visit, the contractor had completed the grade improvement and had 

finished placing the base course using the Advant-Edger in both the northbound and 

southbound directions. The contractor had started paving the wearing course with the 

Advant-Edger and was paving the southbound direction on August 11 (refer to Figure 3). A 

short “control” section without Safety EdgeSM was paved at the end of the day on August 11 

(the contractor was paving from south to north). Portions of the wearing course in the 

northbound direction (towards the south end of the project) had been completed prior to the 

site visit. On August 12, the contractor switched to the TransTech Shoulder Wedge Maker 

and continued paving the northbound direction. Weather conditions during paving were 

sunny to partly cloudy with occasional rain with highs around 85 oF and lows around 60 oF. 
7

Field Evaluation Tests 

Three sections were identified during the paving operation; two Safety EdgeSM sections and 

one section without the Safety EdgeSM device. Field tests were conducted within each test 

section using a TransTech Model PQI 301 density gauge, while slope measurements were 

taken using a straight-edge and six inch ruler along the two Safety EdgeSM sections. Twelve 

cores were also taken in the test sections established during the paving operations. The 

twelve cores were obtained at six different locations within the Safety EdgeSM and nonSafety EdgeSM sections. The cores were taken for calibration of the PQI density gauge 

readings and to observe the mix near the center of the mat and adjacent to the mat’s edge.

The two Safety EdgeSM and one non-Safety EdgeSM (control) test sections were established, 

all on the wearing course. The following summarizes the three sections included in this field 

study. 

1. Section #1 (Refer to Figure 4), Safety EdgeSM placed using Advant-Edger, 

southbound lane, tangent section, 700 ft section starting at Sta 367+53 going north 

(opposite to the direction of traffic). The section starting point is 16 ft north of posted 

speed limit sign, 32 ft north of a telephone pole, and 62 ft north of a driveway. 200 ft 

north of the section start is the center of a driveway to “Long Meadow Estates.” The 

section ends at Sta 374+53 just before a posted sign indicating “Reduced Speed Zone 

Ahead.” At around the 300 ft and 500 ft marks of the section are mailboxes with 

posts. The mailbox at the 500 ft mark is marked as “105.”

2. Section #2 (Refer to Figure 5), no Safety EdgeSM (control section), southbound lane, 

tangent section north of section #1, 500 ft section starting at Sta 385+38 going north 

(opposite to the direction of traffic). The section starting point is 40 ft south of a 

driveway with a culvert. Around 135 ft north of the section starting point is another 

driveway and a mailbox with a wooden post. The mailbox is marked as “166.” 

Another mailbox marked as “177” is around 410 ft north of the starting point. The 

section ends 500 ft north of the starting point at Sta 390+38, 20 ft south of another 

driveway with a culvert. 

3. Section #3 (Refer to Figure 6), Safety EdgeSM placed using TransTech Shoulder 

Wedge Maker, northbound lane, tangent section , 500 ft section starting at Sta 401+15 

going north (in the direction of traffic). The section starting point is 18 ft south of a 

telephone pole and exactly opposite the center of a driveway to “Maple Ridge Road” 

in the southbound direction. About 170 ft north of the starting point is a driveway 

with a culvert and at 242 ft and 482 ft north of the starting point are telephone poles. 

200 ft north of the section start is the center of a driveway to “Long Meadow 

Estates.” The section ends at Sta 406+15, 93 ft before a sign indicating “Farm 

Crossing.”
8

Overview of 

section 2 

constructed 

without using 

Safety EdgeSM

for the 2 inch 

HMA wearing 

course. 

Transition from 

Safety EdgeSM 

to the control 

section (no 

Safety EdgeSM). 

Overview of 

section 1 

constructed 

using Safety 

EdgeSM for both

the 3 inch HMA

base course and 

the 2 inch HMA

wearing course. 

Figure 4. General overview showing the wearing course with Safety EdgeSM. Image taken 

facing the southbound direction around station 374+53, the end of section 1. 

Figure 5. General overview showing the wearing course without Safety EdgeSM. Image taken 

facing the northbound direction around station 385+38, the beginning of section 2. 
9

Overview of section 3 

constructed using Safety 

EdgeSM for both the 3 

inch HMA base course 

and the 2 inch HMA 

wearing course. 

In some locations the 3 

inch base course 

extended past the 2 inch 

wearing course.

Figure 6. General overview showing the wearing course with Safety EdgeSM. Image taken 

facing the northbound direction around station 406+15, the end of section 3 (image shows the 

end of the section and the pavement north of the section). 

Slope Measurements 

Slope measurements were taken using a straight-edge to measure the width and thickness of 

the taper of the Safety EdgeSM (refer to Figure 7). The average slope of the Safety EdgeSM

paved using the Advant-Edger was 54° and that using the TransTech device was 45°. All 

slope measurements are listed in Table A-1 in Appendix A. Figure 8 shows a comparison 

between the slope of the Safety EdgeSM and mat thickness at the edge for the two test 

sections and for the centerline notched joint edge. As shown, there appears to be no 

correspondence between mat thickness and the slope of the Safety EdgeSM.

Break point 

Toe of 

the slope 

A 

B 

Figure 7. Measurement of Safety EdgeSM Angle. 
10

Figure 8. Comparison of the Safety EdgeSM slope and thickness of the HMA adjacent to 

edge of HMA wearing course. 

Other slope measurements were made at random along the Safety EdgeSM in other areas of 

the project, and the results were the same as for the specific Safety EdgeSM sections 

established for future performance reviews. The slope of the Safety EdgeSM was steeper than 

what was planned, particularly for the Advant-Edger. The slope measurements were variable, 

because it was difficult to locate the end of the Safety EdgeSM in areas where some of the 

HMA mixture was under the screed end plate. 

The TransTech Notched Wedge Joint Maker used for the centerline appears to be capable of 

paving with shallow slopes; however, these were at the pavement centerline with good 

uniform support from the underlying pavement layer(s) and not at the edge of the pavement, 

where the support from the lower layers during compaction is expected to be less.

The change in the slopes of the Safety EdgeSM and thickness at the Safety EdgeSM was also 

evaluated as a function of the passes of the individual rollers for the section pavement using 

the TransTech Shoulder Wedge Maker (Refer to Figure 9).

Immediately behind the screed, and prior to the rolling of the HMA mat, the average slope 

was 30°. After the first pass of the breakdown roller, the average slope increased to 33°. 

There was a corresponding increase in average thickness (by about 0.5 inches) at the edge 

since the first pass of the breakdown roller was approximately 3 inches from the edge, 

resulting in some HMA wearing course material being shoved up near the edges. Following 

the second pass of the breakdown roller the average slope increased to 35°. The HMA 

thickness near the Safety EdgeSM was now reduced to an average value of 2.6 inches (from 

3.5 inches) due to the fact that the second pass of the breakdown roller was 1 to 2 inches over 

the edge. 
11

After two passes of the intermediate rubber tire roller (which did not go over the edge in 

either of the two passes but was approximately 3 inches from the edge), the average slope of 

the Safety EdgeSM increase to 41°. There was a slight increase in thickness of the HMA mat 

near the Safety EdgeSM from 2.6 inches to 2.9 inches. Following the first pass of the finish 

roller (over the edge) the HMA mat thickness was reduced to an average value of 2.6 inches. 

The average slope of the Safety EdgeSM was 42°. 

Figure 9. Effect of rolling on the angle of taper and the thickness of HMA wearing course at 

the taper.

Cores 

A total of twelve cores were drilled along the project for the Safety EdgeSM study. For each 

of the three sections (two Safety EdgeSM and one control) four cores were taken at two 

stations. One core was taken close to the edge and the second core was taken 3 feet from the 

edge. Prior to coring, percent compactions were measured using the TransTech PQI 301 at 

the core locations. These cores were taken to measure the bulk specific gravity and percent 

compactions of the compacted HMA mix for developing a correction factor for the PQI 

gauge readings taken adjacent to the edge and within the center of the mat. 

Two cores were also taken at the centerline to obtain the percent compactions near the 

centerline taper constructed using the TransTech Notched Wedge Joint Maker. In addition, 

for calibration of field PQI measurements to core percent compactions, three cores were 

drilled by the contractor. 
12

Table A-2 in Appendix A includes a summary of these test results and bulk specific gravities 

(saturated surface dry) converted to percent compactions. Figure 10 compares the core 

percent compactions taken along the edge and near the center of the steel drum roller for the 

Safety EdgeSM and non-Safety EdgeSM sections. As expected the compactions (and densities) 

near the center of roller are significantly higher than along the edge of the mat (unconfined 

edge). More importantly, the core percent compactions (and densities) taken along the 

pavement’s edge are consistently higher for the Safety EdgeSM section than for the nonSafety EdgeSM. These results suggest that the Safety EdgeSM is providing better confinement 

for rolling an unconfined edge of the mat. 

Figure 10. Comparison of core percent compactions (densities) adjacent to the edge of 

pavement and the near center of the roller. 

PQI Percent Compaction (Density) Results 

Percent compaction measurements were made with a TransTech PQI 301 gauge. Two 

readings were recorded at each station or location. One reading was made at a point adjacent 

to the Safety EdgeSM and one was made at a distance of 3 feet from the Safety EdgeSM (near 

the center of the steel drum roller). The PQI gauge readings are listed in Table A-3 in 

Appendix A. 

PQI readings were taken at the locations of each core. Figure 11 shows a comparison of the 

PQI percent compaction measurements and percent compactions measured on the cores. As 

shown, there is close correspondence between the PQI and core percent compactions for 

locations away from the Safety EdgeSM. However, for locations close to the Safety EdgeSM, 

the lab percent compactions (and densities) were substantially lower than that measured 

using the PQI. This could be due to the fact that the PQI was calibrated for the higher mat 

densities and not for the lower densities at the edges. Adjustment factors were determined for 

the PQI percent compaction readings taken at the Safety EdgeSM and near the center of the 

steel drum roller being used to compact the HMA mat. The adjustment factors are included in 
13

Table A-2 in Appendix A and are used to adjust the PQI readings. The following summarizes 

the factors determined for this project. 

Location Adjustment Factor 

Near Center of Steel Drum 0.997

Adjacent to Safety EdgeSM 0.914

Figure 11. Comparison of the PQI percent compaction readings and percent compactions 

measured on cores recovered from the HMA wearing course. 

The adjusted or corrected percent compactions using the correction factors are also listed in 

Table A-3 in Appendix A. These factors were used to adjust the PQI gauge readings to be 

consistent with the densities that would be measured in the laboratory. 

Figure 12 shows a comparison of the adjusted PQI gauge readings taken adjacent to the 

Safety EdgeSM and in the center of the vibratory steel wheel roller. As shown in the figure, 

the percent compaction near the edge (unconfined edge) for both the Safety EdgeSM sections 

and the control section is substantially lower than the percent compaction at the center of the 

roller (confined edge). 

The other important observation from this data is that there is no statistical difference 

between the percent compactions of Safety EdgeSM sections and the control section near the 

edge. This may likely be due to the fact that the PQI was not calibrated to measure percent 

compactions at the edges. The raw PQI data (without the adjustment using core data) also 

reveals no statistical difference between the three sets of percent compactions. 

Finally there is a small overall trend of higher percent compactions near the edges for areas 

with higher percent compactions near the center of the roller. This may be a result of local 
14

correlations in HMA properties, HMA thicknesses, compaction energies, and support 

conditions. 

Figure 12. Comparison of the adjusted PQI percent compaction readings between the areas 

adjacent to the edge and center of the steel drum roller. 

Observations Made During Paving with the Safety EdgeSM

This section provides an overview of the observations made during the paving and rolling 

operations. 

Safety EdgeSM for Both HMA Lifts 

The Advant-Edger was used to pave the first 3 inch HMA 19 mm base course on the 

compacted variable thickness (nominal thickness of 18 inches for grade improvement) Type 

D aggregate subbase. Figure 13 shows the HMA placed on top of the Type D aggregate 

subbase. Both the Advant-Edger and the TransTech Safety EdgeSM devices were used to pave 

the second 2 inch HMA 12.5 mm wearing course. Each side of the road had to be widened by 

about 8 inches to accommodate the Safety EdgeSM without reducing pavement width. Figure 

14 shows the edge of both lifts. 
15

Figure 13. Paving the lower 3 inch HMA 19 mm base course with the Advant-Edger on the 

compacted Type D aggregate subbase. 

Figure 14. Both HMA lifts were paved using a Safety EdgeSM device. 

Both the 3 inch HMA 19 mm 

base course and the 2 inch HMA 

12.5 mm wearing course were 

paved using a Safety EdgeSM. 

However, the Safety EdgeSM for 

the lower lift at many locations 

did not appear to have a distinct 

slope. 

While paving the 3 inch HMA base 

course a line in the middle of the 

angled edge was made by the AdvantEdger. The material to the right of this 

line is loose. It would seem that the 3 

inch mat thickness was too much for 

the Safety EdgeSM device. A slight 

adjustment to the angle was made by 

spot welding a shim to the back of the 

Advant-Edger.
16

Transition from Safety EdgeSM to non-Safety EdgeSM

The edge of the wearing course placed without a Safety EdgeSM had loose HMA material 

whereas the shape of the Safety EdgeSM was smoother and uniform prior to rolling. After 

rolling the non-Safety EdgeSM still had loose HMA material and the shape Safety EdgeSM

was still uniform but increased in slope. Figure 15 shows the appearance of the Safety 

EdgeSM and non-Safety EdgeSM sections. A close view of the loose-uncompacted HMA at 

the edge of the non-Safety EdgeSM section is shown in Figure 16. One of the benefits of the 

Safety EdgeSM is a relatively smooth edge of pavement. 

No Safety EdgeSM. Note the loose 

materials of the HMA wearing course 

following roller passes. 

Safety EdgeSM slope. Note the slope prior 

to the breakdown roller passes. 

Safety EdgeSM slope. Note the change in 

slope following breakdown roller passes. 

No Safety EdgeSM. Note the loose 

materials of the HMA wearing course 

prior to breakdown roller passes.

Transition from 

Safety EdgeSM

to no Safety 

EdgeSM.

Figure 15. Appearance of the wearing course of the Safety EdgeSM and non-Safety EdgeSM

sections. 
17

Figure 16. Non-Safety EdgeSM control section showing the lack of density at edges even 

after roller passes. 

Centerline Joint Using the TransTech Notched Wedge Joint Maker 

This project also included use of the TransTech Notched Wedge Joint Maker for the 

centerline joint (which is expected could be adapted to form a Safety EdgeSM). Figure 17

shows the vertical edge of the centerline joint is slightly reduced after rolling leaving behind 

an easily mountable edge for vehicles. 

Non-Safety EdgeSM

control section 

following roller passes 

showing lack of 

density at the edge. 
18

Close-up view of 

the centerline edge 

created by the 

TransTech Notched 

Wedge Joint Maker 

immediately behind 

the screed. Note 

that the edge has 

both a vertical 

portion and a sloped 

portion.

Following passes of

the breakdown 

roller, the vertical 

portion of the 

centerline edge 

collapses to some 

extent into the 

sloped portion 

leaving behind a 

recoverable edge. 

Figure 17. Centerline joint paved using the TransTech Notched Wedge Joint Maker before 

and after breakdown roller passes. 
19

The centerline joint for both the 3 inch HMA 19 mm base course and the 2 inch HMA 12.5 

mm wearing course was paved using the TransTech Notched Wedge Joint Maker. 

MaineDOT does not have a specific HMA longitudinal density specification. The 

conventional density testing procedures require cores at least 9 inches from the centerline 

joint. As part of the quality control plan, the contractor also cut cores on the notched wedge 

joint, after both lanes were paved, to determine the density achieved. In their quality control 

plan, the contractor RC and Sons Paving states: 

“At areas where the wedge has been damaged and found to be 

unacceptable: these areas will be isolated, saw cut and the wedge 

removed, no additional pavement will be added. If during the paving 

process, the wedge does not perform as expected and there is an abnormal 

amount of breakage because of yielding gravel base or any other cause, if 

no other remedy is available, the use of the notched wedge joint will be 

suspended.”

For a very short section of the project, MaineDOT and the contractor experimented with the 

TransTech Notched Wedge Joint Maker by raising it a bit to examine if a Safety EdgeSM-like 

shape could be constructed. The final edge looked like it could be recoverable for an errant 

vehicle tire. 

Placement/Paving Operations 

Overall observation of HMA placed on August 11 and August 12 was the surface appeared 

consistent without segregation. Mix considered “normal” not highly stable and not highly 

tender. Figure 18 shows the paver in operation. Figure 19 shows both the TransTech 

Shoulder Wedge Maker and the TransTech Notched Wedge Joint Maker attached to the 

screed. 

End of paver material feed auger was about 2.5 feet from end gate on the Safety EdgeSM side. 

Paver equipment manufacturers recommend that the auger be no more than 18 inches from 

end gate. 
20

Figure 18. Paving operations showing the Safety EdgeSM paved using the Advant-Edger and 

the centerline joint paved using the TransTech Notched Wedge Joint Maker. 
21

Figure 19. TransTech Shoulder Wedge Maker and TransTech Notched Wedge Joint Maker 

attached to the screed. 

TransTech 

Shoulder Wedge 

Maker: adjustments 

to the device had to 

be made to get it to 

rest flush against 

the end plate.

TransTech Notched 

Wedge Joint 

Maker: note the 

vertical portion and 

the sloped portion 

of the device. 

The lower 3 inch 

HMA 19 mm base 

course was also 

paved using the 

TransTech Notched 

Wedge Joint 

Maker.

The lower 3 inch 

HMA 19 mm base 

course was paved 

using the AdvantEdger. 
22

The following summarizes some of the observations and comments made by construction 

personnel on the use of the Safety EdgeSM devices: 

 MDOT Project Manager 

o Safety EdgeSM application – project has shoulder backing material to be 

placed against pavement, so not sure Safety EdgeSM is needed for this project. 

o TransTech Notched Wedge Joint Maker – the TransTech Notched Wedge 

Joint Maker used along the project centerline created a good shape for traffic 

to run on and good density – thought it could be adjusted to be used to make a 

Safety EdgeSM

Production: Safety EdgeSM had no negative impact on production. 

.

o

 Project Foreman 

o Safety EdgeSM device – suggests putting a sleeve around the Safety EdgeSM

spring to keep HMA material out of this area so it does not get into the threads 

and make difficult to adjust the Safety EdgeSM vertically. 

o Safety EdgeSM – likes the shape of the Safety EdgeSM under the screed as 

compared to without the Safety EdgeSM

Device comparisons – the Advant-Edger does not create the desired Safety 

EdgeSM slope as well as the TransTech device, but believes using the Safety 

EdgeSM is better than not using the Safety EdgeSM for pavement performance. 

.

o

o Production – Safety EdgeSM had no negative impact on production. 

 Screed operator 

o Safety EdgeSM device – adding vibration to the device would likely make it 

better. 

o Device comparisons – TransTech device provides better compaction than 

Advant-Edger 

Compaction Operations 

Visual observations of the mat under the roller suggested that the roll down appeared 

“normal” and generally speaking there were no signs of any tearing or shoving (except for 

one 50-100 ft portion of the project as described in this section). 

Three rollers were used to compact the 2 inch HMA 12.5 mm wearing course. The 

breakdown roller was a Caterpillar CB-534D, the intermediate roller was a Caterpillar PS360C, and the finish roller was a Hamm HD-90. 

The Caterpillar steel wheel breakdown roller shown in Figure 20 was a 10-ton roller with 66 

inch drum width. It was operated in the high frequency, low amplitude vibratory mode, with 

only 1 drum vibrating due to the roller “creeping” across the mat. The breakdown roller was 

operated close behind the paver. 

 Caterpillar steel wheel roller; high frequency, low amplitude (only 1 drum vibrating); 

breakdown roller: 

o First pass (forward) with vibrations and 2 to 6 inches off centerline edge joint. 
23

o Second pass (reverse) with vibrations and extended over the centerline edge

joint by about 2 to 6 inches. 

o Third pass (forward) with vibrations and extended over the centerline edge

joint by about 2 to 6 inches. 

o Fourth pass (reverse) with vibrations in the middle of the lane. 

o Fifth pass (forward) with vibrations in the middle of the lane. 

o Sixth pass (reverse) with vibrations in the middle of the lane. 

o Seventh pass (forward) with vibrations and 2 to 6 inches off edge joint. 

o Eight pass (reverse) with vibrations and extended over the edge joint by abou

2 to 6 inches. 

t 

o Ninth pass (forward) with vibrations and extended over the edge joint by 

about 2 to 6 inches. 

The above rolling pattern was performed on both the Advant-Edger section (section 1) and 

the control section (section 2) on August 11. General observation of edge (both the AdvantEdger section and non-Safety EdgeSM section) during rolling was that the top of the mat edge 

was pushing out by approximately 1 inch. 

During the paving on August 12, the HMA was pushing, shoving, and tearing under the 

breakdown roller about 500 ft after paving started. It appeared to be a classic “tender zone” 

problem. Mat temperature was about 185o. Mix in the paver hopper was about 290o and 

immediately behind the screed was 255-260o. Contractor modified rolling pattern after this 

and changed breakdown roller to 6 passes to cover the road and not 9 passes. 

 Caterpillar steel wheel roller; high frequency, low amplitude (only 1 drum vibrating); 

primary or breakdown roller: 

o First pass (forward) with vibrations and 2 to 6 inches off centerline edge joint. 

o Second pass (reverse) with vibrations and extended over the centerline edge 

joint by about 2 to 6 inches. 

o Third pass (forward) with vibrations in the middle of the lane. 

o Fourth pass (reverse) with vibrations in the middle of the lane. 

o Fifth pass (forward) with vibrations and 2 to 6 inches off edge joint. 

o Sixth pass (reverse) with vibrations and extended over the edge joint by about 

2 to 6 inches. 

The above breakdown rolling pattern was performed on the TransTech section (section 3) 

August 12. 
24

Figure 20. Steel wheel roller used in the breakdown position to compact the 12.5 mm HMA 

mix. 
25

The Caterpillar intermediate rubber tire pneumatic roller shown in Figure 21 was operated 

right behind the breakdown roller along most of the areas. The roller had 4 tires (15 inch 

footprint with 9.5 inch gap between tires) in front and 3 tires (15 inch footprint with 9.5 inch 

gap between tires) in back to cover the gaps between the front tires. The roller was operated 

without water ballast; the operator indicated that the tire pressure was about 85 psi (pressure 

set to give good compaction and still allow the finish roller to remove the intermediate roller 

tire marks). 

 Caterpillar intermediate rubber tire pneumatic roller: 

o

o

First pass is on the centerline hanging over about 2 inches. 

6 passes to traverse across the pavement such that with each pass the roller 

moves over about 12 inches. 

o Another 6 passes to traverse back across the pavement.

o Roller does not get any closer to outside edge than 6 inches (so pneumatic 

roller does not roll the outside edge where the Safety EdgeSM is located). 

Figure 21. Rubber tire pneumatic roller used in the intermediate position. 
26

The Hamm finish roller shown in Figure 22 was operated in the static mode. The finish roller 

operator waited to roll the mat until the temperature was less than 130o at the edges of the 

mat. The following summarizes the number of passes and coverage used by the finish roller: 

 Hamm steel wheel roller; static mode; finish roller: 

o First pass (forward) without vibrations and extended over the centerline edge 

joint by about 2 to 6 inches. 

o Second pass (reverse) without vibrations and extended over the centerline 

edge joint by about 2 to 6 inches. 

o Third pass (forward) without vibrations in the middle of the lane. 

o Fourth pass (reverse) without vibrations in the middle of the lane. 

Fifth pass (forward) without vibrations and extended over the edge joint by 

about 2 to 6 inches. 

o

o Sixth pass (reverse) without vibrations and extended over the edge joint by 

about 2 to 6 inches. 

Figure 22. Steel wheel roller used in the finish position. 

Findings and Conclusions 

As previously stated, the objective of this field study is to evaluate the quality of the in-place 

HMA material and Safety EdgeSM by investigating three features: 
27

 Correct use of the Safety EdgeSM device during paving. 

 Safety EdgeSM versus non-Safety EdgeSM portions of project. 

 Slope of the Safety EdgeSM. 

The following findings and conclusions can be made based on the observations made during 

the paving/compaction operations: 

 This project on SR 117 in Turner, Maine, includes construction of Safety EdgeSM

during HMA paving using two types of Safety EdgeSM devices – the Advant-Edger 

and the TransTech Shoulder Wedge Maker. In addition, the project also includes 

paving using a TransTech Notched Wedge Joint Maker for the centerline. Both the 3 

inch HMA 19 mm base course and the 2 inch HMA 12.5 mm wearing courses were 

paved using a Safety EdgeSM device and the centerline notched wedge joint maker, 

except for a short “control” section where the 2 inch HMA 12.5 mm wearing course 

was paved without the use of a Safety EdgeSM.

 Each side of the road had to be widened by approximately 8 inches to accommodate 

the Safety EdgeSM without reducing pavement width. The Safety EdgeSM had no 

negative impact on production. 

 Both the foreman and screed operator believed that the TransTech Shoulder Wedge 

Maker created a better slope and provided better compaction than the Advant-Edger. 

This was also confirmed by the field measurements of the Safety EdgeSM slope 

following rolling. 

 Although both the Advant-Edger and TransTech Shoulder Wedge Maker devices 

produced an edge with a slope of 30o immediately behind the screed, because of the 

difference in device pressure and shape, the slope of the Safety EdgeSM made with the 

Advant-Edger increased to an average of 54o and that of the Safety EdgeSM made with 

the TransTech device increased to an average of 45o after rolling. It should be noted 

that the HMA mix for the surface wearing course was “normal” and not too tender or 

too stiff, and using a mix with a different level of stiffness could result in different 

values. 

 The slope of the centerline edge made with the TransTech Notched Wedge Joint 

Maker had an average value of 19o. Field personnel believed that the TransTech 

Notched Wedge Joint Maker could be adjusted to form a 30o Safety EdgeSM slope. 

 The core percent compaction of the HMA mixture adjacent to the Safety EdgeSM was 

found to be slightly higher than along the unconfined edge in the areas placed without 

the Safety EdgeSM – a positive benefit from the Safety EdgeSM device. However, there 

was no statistical difference in the PQI percent compaction measurements between 

the HMA mixture adjacent to the Safety EdgeSM and the unconfined edge in the 

control areas placed without the Safety EdgeSM.

The Safety EdgeSM should be inspected after the shoulder material has been placed to the 

final pavement elevation. Monitoring of this site would be beneficial in evaluating the longterm performance of the Safety EdgeSM. 
A-1

APPENDIX A. DATA TABLES FROM FIELD MEASUREMENTS 

This section of the field report provides a summary and listing of all field measurements 

recorded during the paving operations. These data are also included in the detailed evaluation 

forms for the Safety EdgeSM demonstration projects. 

Table A-1. Safety EdgeSM Slope Measurements. 

Effect of edge device 

Width of 

Taper Thickness Slope

1A and 1B 100

225 1.38 2.50 61.2

250 2.00 2.50 51.3

275 1.50 2.25 56.3

300 2.25 2.75 50.7

325 1.68 2.50 56.2

350 2.00 2.35 49.6

375 1.75 2.38 53.6

400 2.00 2.50 51.3

425 1.50 1.75 49.4

450 1.75 2.25 52.1

475 1.50 2.38 57.7

500 1.50 2.50 59.0

525 1.50 2.25 56.3

2A and 2B 600

Mean Value 1.72 2.37 54.22

Standard Deviation 0.271 0.234 3.817

Coefficient of Variation 15.8 9.9 7.0

Core/Section 

ID

Station

AdvantEdger Safety Edge

Section Identifier

Area #1; AdvantEdger Safety Edge Section

Width of 

Taper Thickness Slope

6.50 2.63 22.0

7.00 2.50 19.7

7.50 2.50 18.4

7.50 2.38 17.6

Mean Value 7.13 2.50 19.41

Standard Deviation 0.479 0.102 1.919

Coefficient of Variation 6.7 4.1 9.9

Centerline Notched Wedge Maker

Section Identifier

Core/Section

ID

Station

Notched Wedge Maker
A-2

Table A-1. Safety EdgeSM slope measurements (continued). 

Effect of rolling 

Width of 

Taper Thickness Slope

0 4.00 3.00 36.9

25 4.13 3.00 36.0

50 3.25 2.75 40.2

75 3.75 2.63 35.0

5A and 5B 100 2.00 2.50 51.3

125 2.50 2.63 46.4

150 2.38 2.50 46.5

175 2.00 2.50 51.3

200 1.75 2.50 55.0

225 3.25 2.50 37.6

250 3.50 2.75 38.2

275 2.25 2.63 49.4

300 2.00 2.63 52.7

325 1.50 2.38 57.7

350 2.25 2.75 50.7

375 3.25 2.63 38.9

6A and 6B 400 3.25 2.75 40.2

425 2.13 2.38 48.2

450 3.38 2.50 36.5

475 2.00 2.25 48.4

500 3.00 2.50 39.8

Mean Value 2.738 2.601 44.62

Standard Deviation 0.787 0.188 7.092

Coefficient of Variation 28.72 7.23 15.90

Area #3; TransTech Safety Edge Section

Section Identifier

Core/Section 

ID

Station

TransTech Safety Edge

Width of 

Taper Thickness Slope

5.25 2.75 27.6

5.00 3.00 31.0

5.75 3.00 27.6

5.75 3.25 29.5

372 5.75 3.50 31.3

384 5.75 3.50 31.3

412 5.50 3.00 28.6

421 4.50 2.88 32.6

435 5.25 3.00 29.7

Mean Value 5.39 3.10 29.91

Standard Deviation 0.435 0.264 1.761

Coefficient of Variation 8.1 8.5 5.9

Section Identifier

Core/Section 

ID

Station

TransTech Device - Before Roller, Just After Screed
A-3

Table A-1. Safety EdgeSM slope measurements(continued). 

Width of 

Taper Thickness Slope

5.50 3.50 32.5

372 5.00 3.63 35.9

384 5.50 3.75 34.3

412 5.50 3.25 30.6

421

435

Mean Value 5.375 3.531 33.32

Standard Deviation 0.250 0.213 2.312

Coefficient of Variation 4.65 6.05 6.94

Section Identifier

Core/Section 

ID

Station

After First Pass of Breakdown Roller ~ 3 inches from 

Edge

Width of 

Taper Thickness Slope

3.50 2.88 39.4

4.00 2.75 34.5

4.00 2.38 30.7

3.50 2.25 32.7

372 4.00 3.13 38.0

384 4.00 2.75 34.5

412 3.50 2.38 34.2

421 3.50 2.25 32.7

435 3.25 2.63 38.9

Mean Value 3.69 2.60 35.07

Standard Deviation 0.300 0.305 3.035

Coefficient of Variation 8.1 11.7 8.7

Section Identifier

Core/Section 

ID

Station

After Second Pass of Breakdown Roller ~ 1 inch over

the Edge

Width of 

Taper Thickness Slope

372 4.00 3.38 40.2

384 3.75 3.00 38.7

412 3.50 2.63 36.9

421 3.13 2.75 41.3

435 2.25 2.50 48.0

Mean Value 3.33 2.85 41.01

Standard Deviation 0.682 0.347 4.259

Coefficient of Variation 20.5 12.2 10.4

Section Identifier

Core/Section 

ID

Station

After Second Pass of the Rubber Tire Intermediate 

Roller ~ 3 inches from Edge
A-4

Table A-1. Safety EdgeSM slope measurements (continued). 

Table A-2. PQI percent compaction adjustment ratios; core percent compactions.

Width of 

Taper Thickness Slope

372 3.25 2.88 41.5

384 3.25 2.75 40.2

412 3.38 2.50 36.5

421 3.00 2.50 39.8

435 2.00 2.50 51.3

Mean Value 2.98 2.63 41.88

Standard Deviation 0.562 0.177 5.596

Coefficient of Variation 18.9 6.7 13.4

After First Pass of the Finish Roller Over Edge

Section Identifier

Core/Section 

ID

Station

A – Adjacent 

to Edge

B – 3 feet 

from Edge

B – 3 feet 

from Edge

A – Adjacent 

to Edge

A – Adjacent

to Edge

B – 3 feet 

from Edge

1A 1B SB 368+53 AdvantEdger 84.7 93.3 91.7 92.9 0.924 1.004

2A 2B SB 373+53 AdvantEdger 83.6 92.9 91.8 93.1 0.911 0.998

3A 3B SB 386+38 Non-Safety Edge 82.3 92.3 91.3 93.1 0.901 0.991

4A 4B SB 389+38 Non-Safety Edge 82.8 92.4 91.7 93.3 0.903

5A 5B N B 402+12 TransTech 84.0 94.8 91.3 94.3 0.920 1.005

6A 6B N B 405+12 TransTech 83.8 92.4 90.3 93.1 0.928

83.53 93.02 91.35 93.30 0.914 0.997

0.862 0.954 0.558 0.506 0.0111 0.0066

1.03 1.03 0.61 0.54 1.21 0.66

0.990

0.992

Cont. Notched Wedge 93.0 94.5

DOT Notched Wedge 93.3 94.4

Cont. 94.0 93.8

Cont. 95.0 94.3

Cont. 95.0 94.6

Contractor Data Used for 

Calibration of PQI

Core # Lane Adjustment Ratio

Direction

Station Type of Section % Compaction of Cores PQI Values

Section 1 - AdvantEdger 

Safety Edge Section

Section 3 - TransTech Safety 

Edge Section

Area/Location

Mean

Standard Deviation

Coefficient of Variation

Section 2 - Control Section 

(No Safety Edge)

Centerline Notched Wedge 

EdgeMaker
A-5

Table A-3. Percent compaction readings made with a TransTech PQI 301 gauge. 

Adjustment Ratios for PQI 

Gauge:

A = 0.914

B= 0.997

A – Adjacent 

to Edge

B – 3 feet 

from Edge

A – Adjacent 

to Edge

B – 3 feet 

from Edge

0 92.0 93.0 84.1 92.7

25 91.3 93.4 83.4 93.1

50 91.7 93.0 83.8 92.7

75 91.5 93.3 83.6 93.0

1A and 1B 100 91.7 92.9 83.8 92.6

125 92.2 93.3 84.3 93.0

150 92.6 94.1 84.6 93.8

175 92.0 93.5 84.1 93.2

200 92.0 93.3 84.1 93.0

225 90.9 93.4 83.1 93.1

250 91.4 93.3 83.5 93.0

275 92.2 93.1 84.3 92.8

300 91.3 93.1 83.4 92.8

325 91.5 93.3 83.6 93.0

350 91.3 93.4 83.4 93.1

375 90.9 92.9 83.1 92.6

400 91.6 93.3 83.7 93.0

425 91.7 93.2 83.8 92.9

450 91.8 93.5 83.9 93.2

475 91.8 93.1 83.9 92.8

500 91.3 93.0 83.4 92.7

525 91.2 93.2 83.4 92.9

550 91.3 92.9 83.4 92.6

575 91.4 93.2 83.5 92.9

2A and 2B 600 91.8 93.1 83.9 92.8

625 91.8 93.3 83.9 93.0

650 91.9 93.2 84.0 92.9

675 92.1 93.3 84.2 93.0

700 92.1 93.1 84.2 92.8

91.67 93.23 83.78 92.95

0.403 0.239 0.368 0.238

0.44 0.26 0.44 0.26

Adjusted PQI Values

Area #1; AdvantEdger 

Safety Edge Section

Core Location PQI Percent Compactions

Location/Area

Coefficient of Variation

Average Value

Standard Deviation
A-6

Table A-3. Percent compaction readings made with a TransTech PQI 301 gauge (continued). 

Area #3; TransTech Safety 

Edge Section

Coefficient of Variation

Standard Deviation

0 91.7 93.9 83.8 93.6

25 92.0 93.7 84.1 93.4

50 91.1 93.7 83.3 93.4

75 92.1 94.1 84.2 93.8

5A and 5B 100 91.3 94.3 83.4 94.0

125 89.7 93.6 82.0 93.3

150 91.3 93.9 83.4 93.6

175 91.9 93.5 84.0 93.2

200 92.2 93.8 84.3 93.5

225 92.1 93.8 84.2 93.5

250 92.0 93.7 84.1 93.4

275 91.3 93.6 83.4 93.3

300 91.9 93.7 84.0 93.4

325 91.4 93.5 83.5 93.2

350 91.8 93.7 83.9 93.4

375 91.9 93.7 84.0 93.4

6A and 6B 400 90.3 93.1 82.5 92.8

425 91.9 94.1 84.0 93.8

450 92.0 93.9 84.1 93.6

475 92.4 94.2 84.5 93.9

500 91.5 93.8 83.6 93.5

91.61 93.78 83.73 93.49

0.643 0.266 0.587 0.265

0.70 0.28 0.70 0.28

0 91.7 93.0 83.8 92.7

25 91.3 93.2 83.4 92.9

50 92.3 93.6 84.4 93.3

75 91.5 93.2 83.6 92.9

3A and 3B 100 91.3 93.1 83.4 92.8

125 91.8 92.9 83.9 92.6

150 91.8 93.4 83.9 93.1

175 92.4 93.4 84.5 93.1

200 92.5 94.1 84.5 93.8

225 91.9 93.5 84.0 93.2

250 91.7 93.6 83.8 93.3

275 92.6 93.8 84.6 93.5

300 92.2 94.1 84.3 93.8

325 91.8 93.2 83.9 92.9

350 91.6 92.9 83.7 92.6

375 91.9 93.5 84.0 93.2

4A and 4B 400 91.7 93.3 83.8 93.0

425 91.5 93.5 83.6 93.2

450 90.8 92.5 83.0 92.2

475 90.6 93.2 82.8 92.9

500 90.8 93.6 83.0 93.3

91.70 93.36 83.81 93.08

0.543 0.387 0.496 0.385

0.59 0.41 0.59 0.41

Average Value

Standard Deviation

Area #2; Control No Safety 

Edge Section

Coefficient of Variation

Average Value