Report No.ABTR/RD/TM-99/02

Subject Area

Project No.

Report DateMay 13, 1999

Title and SubtitleJoint Study of Roadmarking Retroreflectivity and Highway Paint Durability

Type of ReportInternal

AuthorTed HarrisonGlenn Thamer

No. of Pages

Industry Name and AddressLafrentz Road Services Ltd.8228 Coronet RoadEdmonton, AB T6E 4N7

Agency Name and AddressAlberta Infrastructure 4999 – 98 AvenueEdmonton, AB T6B 2X3

Supplementary NotesThe authors would like to thank the following employees who assisted in this study: Dough Smith, Lafrentz, JimSkwarok, AGRA, Technical Supervisor, Senior Roadway Materials Specialist and Joe Filice, AlbertaInfrastructure, Materials TechnologistAbstractThe durability of traffic paint is dependent on the materials used in the formulation of the paint and the rate atwhich the paint dries and hardens over time. The rate of drying is dependent on the application thickness andthe type of solvent. The rate of hardening is dependent on the type of resin and environment. The rate ofdeterioration is influenced by film thickness and resistance to mechanical and chemical weathering, the amountof traffic, environmental conditions and presence of abrasive materials.

In 1997 and 1998, a joint study was conducted by Alberta Infrastructure and Lafrentz, to determine the effectapplication rate has on retroreflectivity and durability and establish a minimum application rate.

The joint study of painted roadway line retroreflectivity and durability was undertaken to quantify the impact thevarious application rates and repainting strategies have had on the performance levels.

The results of this study indicate that painted roadway lines should be reapplied on a cycle of every 6 to 8months to maintain a minimum retroreflectance level and a minimum general appearance level.

Edge lines repainted annually at the recommended application rate should maximize performance levels. Therecommended application rates range from 25l/km to 40l/km and are selected based on surface type and linecondition.

Distribution Unlimited

Key Words

Project Co-ordinatorTed Harrison, P. Eng. Materials Engineer

DDIISSCCLLAAIIMMEERRThe opinions, findings and conclusions expressed in this report are those of the author. The contents do notnecessarily reflect the official view or policies of the Government of Alberta. This report does not constitute astandard, specification or regulation.

The Government of Alberta does not endorse products or manufacturers. Trade or manufacturer’s names appearherein only because they are considered essential to the object of this document.

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TABLE OF CONTENTS

1.0 INTRODUCTION ..............................................................................................3

2.0 OBJECTIVES ..............................................................................................4

3.0 BACKGROUND 4

APPLICATION RATES STUDIED......................................................................5

RATIONALE FOR APPLICATION RATES..........................................................5

HYPOTHESIS ..............................................................................................6

4.0 RETROREFLECTIVITY STUDY ....................................................................................7

5.0 EQUIPMENT DESCRIPTION........................................................................................8

5.1 CALIBRATION ..............................................................................................8

GENERAL ..............................................................................................8

5.2 OPERATION ............................................................................................10

6.0 FIELD MEASUREMENTS ..........................................................................................10

PROJECT SELECTION..................................................................................10

ROAD SERVICE TEST TRACK ......................................................................11

7.0 DISCUSSION OF RESULTS......................................................................................15

FIELD RESULTS...........................................................................................15

ROAD SERVICE TEST..................................................................................23

8.0 OBSERVATIONS ............................................................................................23

FIELD RESULTS...........................................................................................23

ROAD SERVICE TEST..................................................................................25

NIGHT TIME EVALUATION ............................................................................25

SUMMARY OF OBSERVATIONS...................................................................28

9.0 RECOMMENDATIONS ............................................................................................29

APPENDIX A ............................................................................................30

2

LIST OF CHARTS Page No.

Chart 1 - Lafrentz vs. AGRA Retroreflectance Readings................9

Chart 2 - White General Appearance ................................................13

Chart 3 - White Bead Loss..................................................................13

Chart 4 - White Retroreflectivity..........................................................14

Appendix A

Chart 5 – 37 - Project Retro Readings Comparison.................................29-61

Chart 38 - Overall Trend AGRA ............................................................17

Chart 39 - Overall Trend LaFrentz ........................................................20

Chart 40 - Overall Trend AGRA & LaFrentz ........................................22

LIST OF TABLES

Table 1 - General Appearance ...........................................................11

Table 2 - Bead Loss.............................................................................12

Table 3 - Retroreflectivity.....................................................................12

Table 4 - AGRA Readings...................................................................16

Table 5 - LaFrentz Readings...............................................................18-19

Table 6 - LaFrentz and AGRA (average readings)...........................21

Table 7 - Photo Log..............................................................................63

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ALBERTA INFRASTRUCTURETECHNICAL STANDARDS BRANCH

N O T I C E

This report is published without prejudice as to theapplication of the findings and is disseminated in the interestof information exchange. Alberta Infrastructure does notendorse products or manufacturers. Trademarks and/ormanufacturers appear only where it is considered essentialto the object of the report.

Joint Study of Roadmarking Retroreflectivity andHighway Paint Durability

1.0 INTRODUCTION

Painted roadway lines are a costly routine maintenance activity. The economic

analysis currently used favours the use of traditional alkyd traffic paint over the more

costly durable or long-life systems.

The durability of alkyd traffic paint is dependent on the materials used in the formulation

of the paint and the rate at which the paint dries and hardens over time. The rate of

drying is dependent on the application thickness and the type of solvent. The rate of

hardening is dependent on the type of resin and environment. Highway paint durability

is dependent on the film thickness and resistance to mechanical and chemical

weathering. Typically the thinner the paint the quicker it becomes hard and brittle and

will eventually chip, flake, abrade and deteriorate so that nothing remains on the

surface. The amount of traffic, environmental conditions and the presence of abrasive

materials such as sand will influence the rate of deterioration.

4

The results of this study indicate that painted roadway lines should be reapplied on a

cycle of every 6 months to maintain a minimum retroreflectance level or on a cycle of

every 8 months to maintain a minimum general appearance level. However, our

climate does not permit a 6 to 8-month cyclic repainting program in order to maintain

optimal performance levels.

The variability in application rates used during the past few years combined with the

strategy of repainting an edge line every other year has had a significant influence on

performance levels of painted roadway lines.

This joint study of painted roadway line retroreflectivity and durability was undertaken

to quantify the impact the various application rates and repainting strategies have had

on the performance levels.

2.0 OBJECTIVES

The objectives of the study are:

- determine the effect application rate has on retroreflectivity and durability and

- establish a minimum application rate that would minimize the reduction of

retroreflectivity and durability.

3.0 BACKGROUND

Alberta Infrastructure has traditionally applied painted lines to Alberta highways.

Records of the amount of paint coverage are not available. However, private

contractors, as part of their cost control, can determine with reasonable accuracy the

amount of paint and glass bead used on most lines. Edge line application rate can be

determined with accuracy while the yellow centre line is more difficult due to the

variation in application patterns.

Alberta Infrastructure specifications and repainting strategies have changed from time

to time and vary from Region to Region.

5

Line painting practices are continually being modified as a result of outsourcing and

with the establishment of criteria for Alberta Infrastructure budget allocation standards

based on the stratification of the primary highway network.

Under our current specification line painting has a 60-day warranty period. The method

used for acceptance of paint formulations from a supplier is based on a 6 month

evaluation with the paint applied at 375 µm ± 25 µm (wet film thickness).

Paint Industry estimates the average life expectancy of alkyd paint to be 12-18 months

under normal conditions.

Application Rates Studied:

The three different application rates applied in 1996 and 1997 have been identified for

study. These are:

• 250 µm - Repainting edge line in Southern Region

• 300 µm - Typical 1996 application rate

• 348 µm - Typical 1997 application rate.

Rationale for Application Rates

1. In 1996, the specification for paint and bead application stated that, “All painted

lines shall have a wet film thickness of 375 ± 75 µm (38.7 R/km of solid 100 mm

wide line) and be uniformly covered with glass beads, at the rate of 600 g/R (123

kg/barrel of paint).”

2. The contractors interpreted the application rate to be 375 µm plus or minus 75 µm.

Therefore, the contractors assumed that 30 (R/km) was the lower acceptable

application rate limit and controlled their operations to deliver this amount

throughout the 1996 season.

6

3. The minimum application rate for repainting edge lines in Calgary and Lethbridge

(Southern Region) is specified, under a special provision, to be 250 µm with full

bead application.

4. In 1997, Alberta Infrastructure insisted the specification requirement was 38.7 (R/km)

and agreed to accept 34.8 R/km as the lower limit and the contractors controlled

their operations to deliver this amount of material.

5. The industry standard for painted traffic lines is 15 mils (wet film paint thickness).

The soft conversion from mils to µm is 15*25 = 375 µm (i.e., 1 mil = 25 µm).

6. The hard conversion from mils to µm is 15*25.4 = 381 µm (i.e., 1 mil = 25.4 µm).

The previous standard for line width was four inches or 4*25.4=101.6 mm.

Therefore, the application rate based on a solid 4” wide line is 381(101.6/100) =

387 µm or 38.7 R/km.

7. The application rate for a 100 mm line is 15*25.4(100/100) = 381 µm or 38.1 R/km

using the hard conversion or 37.5 R/km using the soft conversion.

Hypothesis:

• A decrease in application rate will allow rapid loss of the large and intermediate

size beads at an unacceptable rate since the paint holds the bead in place. This

should result in initial high retroreflectance readings followed by rapid deterioration

due to bead loss.

• An increase in paint application rate will result in lower retroreflectance because the

bead sinks into the paint and does not remain on the surface. Retroreflectance

readings could improve or would deteriorate at a slower rate as more beads are

exposed over time.

7

• Applying excessive amounts of glass beads will result in lower levels of

retroreflectivity because the light is diffused by an over abundance of mirrored

surfaces.

• Large size bead loss is primarily due to snow plowing.

4.0 RETROREFLECTIVITY STUDY

A cross section of construction projects were selected and hundreds of retroreflectivity

readings were taken in October and November of 1997 and retaken at the same

locations during March and April of 1998.

This will show the change in retroreflectivity over the course of one winter of plowing.

Five types of locations are identified as follows:

1 1995 paving - these projects were painted initially under a “general” contract.

Today it will have one edge line painted at the 1995 or 1996 (30.0 R/km) rate

and the other edge line painted at the 1997 (34.8 R/km) rate. The centreline will

have been painted either two or three times.

2 1996 paving - these projects were painted initially under the “general” contract.

Today it will have one edge line painted in 1996 (30.0 R/km) and the other

painted in 1997 (34.8 R/km), unless all lines were painted in 1997. The centreline

will have been painted twice.

3 Chip Seal prior to 1995 – One edge line will have been painted at the 1996

(30.0 R/km) application rate and the other using the 1997 (34.8 R/km) rate. All

three lines will have many years of paint build-up under the latest paint

application.

8

4 Calgary and Lethbridge Regions – The specification calls for edge lines to be

repainted at 250 microns (25.0 R/km) of paint. Some edge lines will have been

repainted in 1996 and some in 1997. The application rate was the same for

both years.

5 Locations that have not been repainted and are in poor condition will be

photographed.

It is expected that this joint Government-Industry study will contribute to our knowledge

of highway paint durability and establish a standard practise for painted roadway lines

for Alberta highways.

5.0 EQUIPMENT DESCRIPTION

Lafrentz Road Services has two Mirolux 12 retroreflectometers and several personnel

with extensive experience with retroreflectivity. Only one instrument was used during

the study to reduce variation that may occur between the two instruments.

AGRA Engineering has one Mirolux 12 retroreflectometer and personnel formerly with

Alberta Infrastructure with extensive experience with retroreflectivity.

Alberta Infrastructure personnel will be involved in all aspects of the study.

5.1 CALIBRATION

General

Duplicate retroreflectivity testing was carried out on Highway 2, between Edmonton

and Lacombe (north and southbound lanes), to determine the repeatability and

reproducibility of the equipment (Lafrentz versus AGRA).

9

A comparison of the average retroreflectance values for each set of readings is shown

in Chart 1. Although a difference exits between the two devices the trend in identifying

high to low values is similar.

Chart 1

The focus of this investigation is to understand what can be done to minimize the rate

of deterioration and not to establish a standard value for retroreflectance. There are

numerous studies underway dealing with the creation of a retroreflectivity standard and

method of measurement.

L a f r e n t z v s A G R A R e t r o r e f l e c t a n c e R e a d i n g s

1 3 5 7 9 11 13 15 17 19 21 23 25

L o c a t i o n

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5.2 OPERATION

The equipment was calibrated and the voltage checked at the start of each location.

The device was wrapped in a shroud to eliminate all external light infiltration.

Lafrentz re-calibrated the device after 3-5 stops, every ½ hour, at the end of each

section or when the instrument gave erratic readings. The voltage was never allowed

to fall below 10.9 volts.

AGRA checked calibration and voltage at the beginning of each test location.

6.0 FIELD MEASUREMENTS

Project Selection

Test sites were located where traffic would be less likely to travel on the line and

adjacent to a reference point such as a sign indicating school bus ahead, distance

marker, odometer test, curve or town ahead.

Each test site was marked and the direction of travel, surface type, reference marker,

general condition, and if line was original “ONCE” or repainted “MANY” noted.

Anomalies between the general condition and retroreflectivity were noted for additional

night time evaluation.

Photos were taken of most sites or of lines in poor condition.

Projects were selected based on the year constructed. Three readings were taken at

each test site and in the direction of travel for that line. The number of sites within a

project varied based on the length of project, consistency of lines and safety.

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Road Service Test Track

In addition to the field evaluation, retroreflectivity readings were taken on the Road

Service Test Track (located on Highway 16 EBL, east of Highway 21 overpass) in

order to determine the rate of deterioration of the 1997 paint tender samples. These

results will be compared to the subjective rating that was established by the evaluation

panel.

Results of the 1997 tender sample Road Service Test were evaluated after one year

to determine the acceptable performance levels of alkyd, fast dry alkyd and waterborne

traffic paints. These results were compared to a 1997 batch sample as a baseline

(Tables 1,2 & 3).

Table 1 – General Appearance

1997 Tender(samples) White paint (General Appearance)Type Days since Application

46 80 116 151 179 193 539

Coning 8.38 7.76 7.33 6.94 6.62 6.45 3.75

Fast Dry 7.98 7.41 7.07 6.62 6.27 6.11 3.65

Waterbourne 7.33 6.89 6.62 6.19 5.86 5.69 3.66

Batch(coning) 8.5 8.29 7.89 7.57 7.2 7.01 4.35

* Scoring is on a scale from 0 – 10 for general appearance and bead loss. 10

being the score at the time of application. A control specimen is used for

comparing each line.

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Table 2 – Bead Loss

1997 Tender(samples) White PaintType Days since Application

46 80 116 151 179 193 539

Coning 8.25 7.65 7.21 6.76 6.46 6.30 3.08

Fast Dry 6.92 6.26 5.81 5.35 5.04 4.98 2.34

Waterbourne 6.75 6.08 5.69 5.21 4.85 4.70 2.22

Batch(coning) 8.00 7.47 7.13 6.69 6.39 6.22 2.72

Table 3 – Retroreflectivity

1997 Tender(samples) White Paint(N) Type Days since Application

46 80 116 151 179 193 372(1year)

3 - Coning 168 145 141 115 105 75 80

6 - Fast Dry 141 134 117 96 86 68 74(Omit sample -25) (151) (146) (126) (103) (93) (73) (78)

4 - Waterbourne 193 168 160 123 103 77 74

1 - Batch(coning) 126 132 132 107 99 66 81

* Retroreflectivity is measured in mcd/m2/lux.

The ratings for general appearance, bead loss and retroreflectivity were averaged for

each paint type and plotted (Charts 2, 3 and 4).

13

Chart 2

Chart 3

White Bead Loss (1997 Tender Samples)

0

1

2

3

4

5

6

7

8

9

0 100 200 300 400 500 600

Days Since application

Wei

ghte

d A

vera

ges

Coning

Fast Dry

Waterbourne

Batch(Coning)

White General Apperance (1997 Tender Samples)

0

2

4

6

8

10

0 100 200 300 400 500 600

Days Since Application

Wei

ghte

d A

vera

ges

Coning

Fast Dry

Waterbourne

Batch(Coning)

14

Chart 4

White Retro-Reflectivity (1997 tender samples)

0

20

40

60

80

100

120

140

160

180

200

0 50 100 150 200 250 300 350 400

Days

Ret

ro R

eadi

ng

Conning

Fast Dry

Waterbourne

Batch (conning)

Pavement

15

7.0 DISCUSSION OF RESULTS

Field Results

The following process was used to review and generate the attached tables, charts and

graphs.

1. The average of the three readings was calculated for each test site.

2. These results were reviewed to determine what criteria should be used to complete

the analysis. The following steps were used to analysis the data collected.

A. The white edge lines were selected for the analysis. The yellow centre and

white lane lines were omitted due to insufficient sample size.

B. The results are identified as belonging to either Lafrentz or AGRA.

The 1997 and 1998 test site averages were determined for each edge line and a line graph

generated for each project (Charts 5 – 37, Appendix A). The edge lines are identified and

labelled as “once” or “many” (where applicable) to indicate the number of applications. In

some cases the edge line, which should have received a single application, had been

repainted under warranty.

C. Projects are grouped by year paved and the average for each edge line was

determined along with the difference between the 1997 and 1998 results

(Table 4 - 5 & Charts 38 - 40).

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Table 4

AGRA (readings)

1997avg.Readings

1998avg.readings

No. Diff. + or-

Comments

Paved 1994Mean SDV Mean SDV

Hwy 2:22(SB)(many)(good)

114.8 24.5 105.5 25.9 4 -9.3 Line is fading, chipped greyish, one coat some cracks

Hwy 2:12 (SB)(many)(good)

98.3 9.6 93.7 4.0 3 -4.6 Lack of beads, dirtyPaint looks good (new?)

1994 average 106.5 99.6 -6.9

Paved 1995Hwy 43:08(SB)(once)

(poor)97.5 38.6 82.0 20.6 4 -15.5 chipping, cracking, failed, poor

Hwy 43:08(NB)(many)(good)

135.5 16.8 133.5 20.5 4 -2.0 not as chipped or cracked,good

Hwy 43:10(SB)(once)(poor)

127.0 33.7 96.0 8.6 5 -3.1 chipping, worn, poor

Hwy 43:10(NB)(many)(good)

133.6 36.4 128.6 24.6 5 -5.0 some chipping, cracked,yellowish colour, good

1995 average once 112.3 105.5 -6.81995 average many 139.6 129.0 -10.6

Mean SDV Mean SDVPaved 1996

Hwy 2:10(many)(good) 158.5 143 2 -15.5 Two coats, overspray, chippedHwy 2A:14(EB)(once)

(poor)99.6 5.6 100.0 1.7 3 N/C Faded, cracked & chipped

Note: acceptable night timevisibility on narrow band.

Hwy 2A:14(WB)(many)(OK)

140.3 8.5 138.7 15.0 3 -1.6 faded, snow plough damage,yellowish, good beam.

Hwy 43:12(SB)(once)(OK)

97.0 14.4 89.8 15.0 4 -7.2 some cracks & chips

Hwy 43:12(once)(poor) 85.5 18.2 73.5 15.3 4 -12.0 badly chipped & crackedHwy 43:14(once)(OK) 142.0 109.0 2 -33 chipped and cracked1996 average once 106.1 93.1 -13.01996 average many 149.4 140.8 -8.6

17

Chart 38

O v e r a l l T r e n d A G R A A v e r a g e H w y . R e t r o R e a d i n g sfor 1997 & 1998

0

50

100

150

200

250

300

96pave

ment

95pa

vemen

t

94pa

vemen

t

Y e a r p a v e d

Val

ues

1997(many)

1998(many)

1 9 9 7 ( o n c e )

1 9 9 8 ( o n c e )

Pavemen t

18

Table 5

LaFrentz (readings)

1997avg.Readings

1998avg.readings

No. Diff. + or - Comments

Paved 1996Mean SDV

Hwy 2:30(NB)(once) 136.4 152.2 5 +15.8Hwy 2:30 (SB)(once) 154.3 152.3 3 -2.0Hwy 2:30 (NB) (many) 219.6 165.6 5 -54.0Hwy 2:30 (SB)(many) 225.6 173.1 9 -52.5Hwy 41:06 (NB)(once) 161.8 153.2 10 -17.1Hwy 41:06 (SB)(many) 222.9 179.1 9 -43.8Hwy 55:16 (EB) (once) 144.6 96.2 9 -48.4Hwy 55:16 (WB) (many) 178.8 132.7 9 -46.1

1996 average once 149.3 138.5 -11.21996 average many 211.7 162.6 -49.1

Paved 1995Hwy 16:20 (EB) (once) 178 158 5 -20.0Hwy 16:22 (WB) (once) 166.6 147.4 5 -19.20Hwy 16:22 (EB) (once) 163.6 169.4 5 +5.8Hwy 27:10 (WB) (many) 110.1 117.0 8 +6.9Hwy 27:10 (EB) (once) 157.5 140.1 8 -17.4Hwy 36:08 (NB) (many) 151.6 137.8 -13.8Hwy 36:08 (SB) (once) 164 148.8 -15.2Hwy 53:10 (WB) (many) 121.8 106.4 -15.4Hwy 53:10 (EB) (once) 244.2 212.8 -31.4Hwy 53:10 (WB) (many) 127.8 122.6 -5.2Hwy 53:10 (EB) (once) 171.8 145.8 -26.0

1995 average once 178.0 160.4 -17.61995 average many 127.8 120.9 -6.9

1994 pavedHwy 2:20 (NB) (many) 174.5 155.6 17 -18.9Hwy 16:24 (EB) (many) 182.4 151.0 5 -31.4Hwy 23:06 (NB) (many) 157.7 131.5 6 -26.2Hwy 23:06 (SB) (many) 185.8 156.5 6 -29.3Hwy 23:08 (WB) (many) 114.4 127.4 9 +13.0Hwy 23:08 (EB) (many) 191.1 185.4 9 -5.7Hwy 43:22 (WB) (many) 265.2 182.3 6 -82.9

1994 average many 181.6 155.7 -25.9

19

1997avg.Readings

1998avg.readings

No. Diff. + or - Comments

1993 paved

Hwy 2:28 (NB) (many) 189.6 153.0 6 -36.7Hwy 13:10 (WB) (many) 169.9 134.9 10 -35.0Hwy 13:10 (EB) (many) 185.8 164.7 9 -21.1Hwy 21:12 (NB) (many) 129.4 145.5 20 +16.1Hwy 21:12 (SB) (many) 187.1 196 20 +8.1

1993 average many 172.4 158.8 -13.6

1992 paved

Hwy 21:24 (NB) (many) 175.0 133.0 -42.0Hwy 21:24 (SB) (many) 147.0 116.0 -31.0Hwy 21:24 (SB) (many) 136.1 136.1 N/CHwy 21:24 (NB) (many) 184.3 158.9 -25.4Hwy 21:26 (NB) (many) 150.2 120.5 -29.7Hwy 21:26 (SB) (many) 187.8 144.4 -43.4

1992 average many 163.4 134.8 -28.6

20

Chart 39

O v e r a l l T r e n d L a f r e n t z A v e r a g e H w y . R e t r o R e a d i n g s f o r 1 9 9 7 & 1 9 9 8

0

5 0

1 0 0

1 5 0

2 0 0

2 5 0

3 0 0

96 pav

ement

Y e a r p a v e d

Val

ues

1 9 9 7 ( m a n y )

1 9 9 7 ( o n c e )

1 9 9 8 ( m a n y )

1 9 9 8 ( o n c e )

P a v e m e n t

21

D. Based on the year paved, an overall average was determined for the “once” and

“many” edge lines (Table 6, Chart 40).

Table 6

LaFrentz & AGRA (average readings)

1997avg.Readings

1998avg.readings

Diff. + or - Comments

Paved 1992

LaFrentz (many)(good) 163.4 134.8 -28.6

Paved 1993

LaFrentz (many)(good) 172.4 158.8 -13.6

Paved 1994

LaFrentz (many) (good) 181.6 155.7 -25.9

AGRA (many) (good) 106.5 99.6 -6.9

Paved 1995

LaFrentz (many) (good) 178.0 160.4 -17.6LaFrentz (once) (poor) 127.8 120.9 -6.9AGRA (many) (good) 139.6 129.0 -10.6AGRA (once) (poor) 112.3 105.5 -6.8

Paved 1996

LaFrentz (many) (good) 211.7 162.6 -49.1LaFrentz (once) (poor) 149.7 138.5 -11.2AGRA (many) (good) 149.4 140.9 -8.5AGRA (once) (poor) 106.1 93.1 -13.0

22

Chart 40

Overall Trend Agra & Lafrentz Average Retro readings for 1997 & 1998

0

50

100

150

200

250

300

96pavement 95pavement 94pavement 93pavement 92pavement

Year Paved

Val

ues

AGRA(many-1997)

AGRA(many-1998)

AGRA(once-1997)

AGRA(once-1998)

LAF(many-1997)

LAF(many-1998)

LAF(once-1997)

LAF(once-1998)

pavement

Agra(many97)

Agra(many98)

Agra(once97)

Agra(once98)

Laf(many97)

Laf(many98)

Laf(once97)

Laf(once-98)

23

Road Service Test

The criteria used to analyze general appearance, bead loss and retroreflectivity results are:

A. A rating of 6.5 is the minimum acceptable performance level for general

appearance or bead loss.

B. Retroreflectivity below 100 mcd/m2/lux requires repainting (using AGRA

Mirolux 12 meter).

Using the results from Tables 1, 2 and 3 and these criteria the approximate service life of

the Road Service Test site materials are:

GeneralAppearance

Bead Loss Retroreflectivity

Days Months Days Months Days Months

ALKYD

Batch (coning) 259 8.6 168 5.6 178 6.0

Coning 189 6.3 191 6.4 181 6.0

Fast Dry 161 5.4 68 2.3 144 4.8

WATERBORNE* 126 4.2 59 2.0 181 6.0

* Dual Coated large Glass beads used.

8.0 OBSERVATIONS

Field Results

An increase in application rate does not have a significant influence on the residual

retroreflectance after a winter cycle but does improve the durability and general

appearance of the edge line. Edge line durability and rate of deterioration is a function

of the time it is exposed to weather, oxidization and to a lesser degree snow plow and

vehicle damage.

24

25

Repainted edge lines (“Many”) generally have a higher initial retroreflectivity reading than

edge lines painted “Once” (Charts 38, 39, 40).

After one winter cycle, repainted edge lines retain a higher level of residual retroreflectivity

than edge lines only painted “Once” (Charts 38, 39, 40).

Repeated repainting at a reduced rate provides better durability performance than a

higher application rate on alternative years.

Road Service Test

The level of retroreflectance decreases to a constant level after a winter cycle (Chart 4).

Retroreflectivity will continue to decrease after each winter cycle.

The expected service life of painted lines (37.5 R/km) is approximately 6 months based on

the results of the Road Service Test site.

Night Time Evaluation

A night time inspection was carried out to validate retroreflectivity readings that appeared

to be suspicious when compared to the general appearance of adjacent edge lines or

highway sections.

The following is a summary of those observations:

Highway 2A:14

The northbound edge line was rated as poor and the general appearance described as

faded, cracked, and chipped and requires immediate repainting. However, the

retroreflectance readings did not indicate that the line would require immediate repainting

26

The night time visibility inspection confirms that the retroreflectivity of the edge line would

provide acceptable traffic guidance. However, it was noted that the glass beads were

concentrated on a very narrow band towards the centre of the line.

One possible explanation could be attributed to the open surface texture of this pavement

type. This project was designed using the SuPerPave mix design method that results in

a much coarser grading than our traditional dense graded mixes. The coarser surface

texture could hold larger beads within the voids and therefore provide higher

retroreflectivity with fewer beads.

Highway 2:22 S/B

The visual inspection confirms that the readings may be lower than section 2:20 S/B and

that both sections are acceptable after one winter.

Highway 2:22 N/B

This section appears to be slightly more retroreflective or “more Substantial” than 2:20

N/B, confirming the retroreflectivity readings.

Highway 2:28 and 2:30 N/B

These sections are acceptable after one winter, confirming the retroreflectivity readings.

Highway 13:10 and 21:24

Both sections appear very retroreflective on both sides, once again confirming the

retroreflectivity readings of the instrument.

Based on the above sections the evaluation team is confident that the retroreflectivity

readings obtained from the Mirolux 12 provided an acceptable comparison to night time

27

visibility.

28

Summary of Observations

1. Results presented in Table 6, Chart 40, LaFrentz & AGRA (average readings),

indicate that residual reflectivity is marginally improved if line durability is maintained.

2. Alkyd paint reapplied annually will maintain line durability and higher levels of residual

retroreflectivity.

3. An Increase in application rate will provide improved durability with minimal

improvement in retroreflectivity. Conversely a reduction in application rate will

increase the initial retroreflectivity but durability will decrease.

4. Retention of large and intermediate size glass beads is dependent on the type of paint,

surface texture and application rate. The larger glass beads used with the waterborne

tender samples provided higher initial retroreflectivity but exhibited rapid deterioration

after 5 months of service (Table 2, 3 and Charts 3, 4).

5. Thicker films of slower drying paints (coning) will hold large and intermediate size

beads longer than faster drying paints (Charts 3,4).

6. Painted roadway lines should be repainted on a 6-month cycle to maintain minimum

acceptable retroreflectivity performance levels.

7. Painted roadway lines should be repainted on a 6 to 8-month cycle, using coning alkyd

paint, to maintain minimum acceptable durability performance levels.

8. Edge lines repainted annually at an appropriate application rate will maximize

29

performance levels.

9.0 RECOMMENDATIONS

The recommended application rates to optimize durability and retroreflectivity

performance are:

MINIMUM APPLICATION RATE:(R/km)

SURFACE TYPE OR LINE CONDITION:

30.025.0

RE-STRIPING: Centre lines, Lane Lines.Edge Lines in good condition

38.0NEW PAVEMENT: (Fine or Closed Textured)Centre Lines, Lane Lines and Edge Lines.RE-STRIPING: Centre Lines, Lane Lines andEdge Lines in poor condition

40.0NEW PAVEMENT(Coarse or Open Textured)and CHIP SEAL COAT: Centre Lines, LaneLines and Edge lines on the Chip SealedSurface

30

APPENDIX A

31

Chart 5

Hwy 2:22 (1994 pavement), Retro Readings Comparison (1997 vs 1998)

0

50

100

150

200

250

300

1 2 3 4

Location Number

Val

ues

1997SB

1998SB

32

Chart 6

Hwy 2:12 (1994 pavement), Retro Readings Comparison (1997 vs 1998)

0

50

100

150

200

250

300

1 2 3

Location Number

Val

ues

1997SB

1998SB

33

Chart 7

Hwy 43:08 SB (1995 pavement), Retro Readings Comparison (1997 vs 1998)

0

50

100

150

200

250

300

1 2 3 4 5

Location Number

Val

ues

1997SB(once)

1997NB(many)

1998SB(once)

1998NB(many)

34

Chart 8

Hwy. 43:10 SB (1995 pavement), Retro Readings Comparison (1997 vs 1998)

0

50

100

150

200

250

300

1 2 3 4 5

Location Number

Val

ues

1997SB

1997NB

1998SB

1998NB

35

Chart 9

Hwy 1:06 (1995 pavement) Retro Readings Comparison (1997 vs 1998)

0

50

100

150

200

250

300

1 2 3

Location Number

Val

ues

1997WB

1997EB

1998WB

1998EB

36

Chart 10

Hwy. 2:10 (1996 pavement), Retro Readings Comparison (1997 vs 1998)

0

50

100

150

200

250

300

0 1 2 3

no. of readings

Val

ues

1997(many)

1998(many)

37

Chart 11

Hwy 2A:14 (1996 pavement), Retro Readings Comparison (1997 vs 1998)

0

50

100

150

200

250

300

1 2 3

Location Number

Val

ues

1997 e.side

1997 w. side(many)

1998 e. side

1998 w. side(many)

38

Chart 12

H w y 4 3 : 1 2 S B ( 1 9 9 6 p a v e m e n t ) R e t r o R e a d i n g s C o m p a r i s o n ( 1 9 9 7 t o 1 9 9 8 )

0

5 0

1 0 0

1 5 0

2 0 0

2 5 0

3 0 0

1 2 3 4

L o c a t i o n N u m b e r

Val

ues

1 9 9 7 S B ( o n c e )

1 9 9 7 N B ( o n c e )

1 9 9 8 S B ( o n c e )

1 9 9 8 N B ( o n c e )

39

Chart 13

H w y 4 3 : 1 4 S B ( 1 9 9 6 p a v e m e n t ) , R e t r o R e a d i n g s C o m p a r i s o n ( 1 9 9 7 v s 1 9 9 8 )

0

5 0

1 0 0

1 5 0

2 0 0

2 5 0

3 0 0

1 2

L o c a t i o n N u m b e r

Val

ues

1 9 9 7 S B ( o n c e )

1 9 9 7 N B ( o n c e )

1 9 9 8 S B ( o n c e )

1 9 9 8 N B ( o n c e )

40

Chart 14

Hwy. 2:30 NB(1996 pavement), Retro Readings Comparisons (1997 vs 1998)

050

100150200250300

0 1 2 3 4 5 6

Location No.

Val

ues

1998NB(many)

1997NB(many)

41

Chart 15

Hwy. 2:30NB (1996 pavement), Retro Readings Comparison (1997 vs 1998)

0

50

100

150

200

250

300

0 1 2 3 4 5 6

Location Number

Val

ues

1998NB

1997NB

42

Chart 16

Hwy. 2:30 SB (1996 pavement), Retro Readings Comparison (1997 vs 1998)

0

100

200

300

0 1 2 3 4

Location Number

Val

ues

1998SB

1997SB

43

Chart 17

Hwy. 2:30 SB(1996 pavement), Retro Readings Comparisons (1997 vs 1998)

0

50

100

150

200

250

300

0 1 2 3 4 5 6 7 8 9 10

Location No.

Val

ues

1998SB

1997SB

44

Chart 18

Hwy 55:16 WB(1996 pavement), Retro readings comparison (1997 vs 1998)

0

50

100

150

200

250

300

1 2 3 4 5 6 7 8 9

Location Number

Val

ues

1997(WB)

1998(WB)

1997(EB)

1998(EB)once

once

many

many

45

Chart 19

Hwy. 41:06 (1996 pavement) , Retro Readings Comparison (1997 vs 1998)

0

5 0

1 0 0

1 5 0

2 0 0

2 5 0

3 0 0

Loca t ion Number

Val

ues

1997(NB)

1998(NB)

1997(SB)

1998(SB)

m a n y

once

m a n y

once

many

46

Chart 20

Hwy. 16:20 EB(1995 pavement), Retro Readings Comparison (1997 vs 1998)

0

50100150200250300

0 1 2 3 4 5 6

Location Number

Val

ues

1998EB(many)

1997EB(many)

47

48

Chart 21

Hwy. 16:22WB (1995 pavement), Retro Readings Comparison (1997 vs 1998)

0

50

100

150

200

250

300

0 1 2 3 4 5 6

no. of readings

Val

ues

1997(many)

1998(many)

49

Hwy. 16:22 EB, (1995 pavement), Retro Readings Comparison (1997 vs 1998)

0

50

100

150

200

250

300

0 1 2 3 4 5 6

no. of readings

Val

ues

1997(many)

1998(many)

50

Chart 22

51Chart 23

Hwy. 27:10(east)(1995 pavement), Retro Readings Comparison (1997 vs 1998)

0

50

100

150

200

250

300

1 2 3 4 5 6 7 8

Location Number

Val

ues

1997EB

1997WB

1998EB

1998WB

many

once

many

once

52

Chart 24

Hwy. 36:08(1995 pavement) , Red Deer River N. , Retro Readings Comparison (1997 vs 1998)

0

5 0

100

150

200

250

300

1 2 3 4 5 6 7 8 9 1 0

L o c a t i o n N u m b e r

Val

ues

1997NB

1997SB

1998NB

1998SB

once

many

once

many

53

Chart 25

Hwy 53:10EB (1995 pavement), Retro Readings Comparisons (1997 vs 1998)

0

50

100

150

200

250

300

1 2 3 4 5 6 7 8

Locat ion Number

Val

ues

1997EB(many)

1997WB(once)

1998EB(many)

1998WB(once)

54

Chart 26

Hwy. 53:10.(1995 pavement), Retro Readings Comparison (1997 vs 1998)

0

50

100

150

200

250

300

350

1 2 3 4 5 6 7

Location Number

Val

ues

1997(EB)

1997(WB)

1998(EB)

1998(WB)

96paint 96paint96paint

96paint 96paint 96paint

once

once

many

many

55

Chart 27

H w y . 2 : 2 0 N / B ( 1 9 9 4 p a v e m e n t ) , R e t r o R e a d i n g s C o m p a r i s o n ( 1 9 9 7 v s 1 9 9 8 )

0

5 0

1 0 0

1 5 0

2 0 0

2 5 0

3 0 0

0 1 2 3 4 5 6 7 8 9 1 0 1 1 1 2 1 3 1 4 1 5 1 6 1 7 1 8

L o c a t i o n N u m b e r

Val

ues

1 9 9 7 N B( m a n y )

1 9 9 8 N B( m a n y )

56

Chart 28

Hwy. 16:24(1994 pavement), Retro Readings Comparison (1997 vs 1998)

0

50

100

150

200

250

300

0 1 2 3 4 5 6

Location Number

Val

ues

1998WB(many)

1997WB(many)

57

Chart 29

Hwy. 23:06 NB (1994 pavement) , Retro Readings Compar ison (1997 vs 1998)

0

50

100

150

200

250

300

1 2 3 4 5 6

L o c a t i o n N u m b e r

Val

ues

1997NB

1997SB

1998NB

1998SB

58

Chart 30

Hwy 23:08WB (1994 pavement), Retro Readings Comparison(1997 vs 1998)

0

50

100

150

200

250

300

1 2 3 4 5 6 7 8 9 10

Location Number

Val

ues

1997WB

1997EB

1998WB

1998EB

59

Chart 31

Hw y. 43:22(1994 pavement), Retro Readings Comparison(1997 vs 1998)

050

100150200250300350

0 1 2 3 4 5 6 7

Location Number

Val

ues

1998WB(many)

1997WB(many)

60

Chart 32

Hw y 2:28 (1993 pavement), Retro Readings Comparison (1997 vs 1998)

0

50

100

150

200

250

300

1 2 3 4 5 6

Location Number

Val

ues

1997NB

1998NB

61

Chart 33

Hwy 13:10WB (1993 pavement), Retro Readings Comparison (1997 vs 1998)

0

50

100

150

200

250

300

1 2 3 4 5 6 7 8 9 10

Location Number

Val

ues

1997WB

1997EB

1998WB

1998EB

62

Chart 34

Hwy 21:12 Start at Hwy. 1 NB (1993 pavement), Retro Readings Comparison (1997 vs 1998)

0

50

1 0 0

1 5 0

2 0 0

2 5 0

3 0 0

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20

Locat ion Number

Val

ues

1997NB

1997SB

1998NB

1998SB

63

Chart 35

H w y 2 1 : 2 4 N B ( 1 9 9 2 p a v e m e n t ) , R e t r o R e a d i n g s C o m p a r i s o n ( 1 9 9 7 v s 1 9 9 8 )

0

5 0

1 0 0

1 5 0

2 0 0

2 5 0

3 0 0

1 2 3 4 5 6 7 8

L o c a t i o n N u m b e r

Val

ues

1997NB

1997SB

1998NB

1998SB

64

Chart 36

H w y 2 1 : 2 4 ( 1 9 9 2 p a v e m e n t ) , R e t r o R e a d i n g s C o m p a r i s o n ( 1 9 9 7 v s 1 9 9 8 )

0

5 0

1 0 0

1 5 0

2 0 0

2 5 0

3 0 0

1 2 3 4 5 6 7 8

L o c a t i o n N u m b e r

Val

ues

1 9 9 7 S B

1997NB

1 9 9 8 S B

1998NB

65

Chart 37

Hwy 21:26 SB (1992 pavement), Retro Readings Comparison (1997 vs 1998)

0

50

100

150

200

250

300

1 2 3 4 5 6 7 8 9

Location Number

Val

ues

1997SB

1997NB

1998SB

1998NB

66

PHOTO LOG

67

TABLE 7PHOTO LOG

Location Surface Line WhiteLine

YellowLine

Picture #

Appearance Retro RetroHwy. 2 Southbound

- L.0.055 Sign ACP Good 145 1

- Carmacks Sign ACP Good 122 2

- Calgary 89 Km. on chip seal Poor 76 3

- Calgary 31 Km. off chip seal Good 133 4on ACP

- Calgary 64 Km. Good 146 114 5

- Scott Hill chipseal Poor 43 6

Hwy. 43:08 (1995) ACP Many, Good 103 7(Roadside Turnout 1Km.)

Once, Poor 61

Hwy. 43:10 (1995) ACP Many, Good 142 8SuPerPave Poor, Once 96(Curve Sign)

Hwy. 43:12 (1996) ACP Once 81 9Albino Moose) Once 84

68

69

70

71

72

73

74