Pavement Marking

Retroreflectivity Performance

in Costa Rica

21st Canadian Multidisciplinary Road Safety Conference,

21e Conférence canadienne multidisciplinaire sur la sécurité routière

Javier Zamora-Rojas

Road Safety Engineer (MScE)

Lanamme – University of Costa Rica

COSTA RICA

• Territory: 51,100 km2

• Population: 4,500,000

• Official language: Spanish

• Tourism: > 2 million/year

• No army since 1948

Few facts:

Introduction

• Pavement marking in Costa Rica

• Solvent-borne traffic paint

• Waterborne traffic paint

• Thermoplastic material

• Retroreflective glass beads

• Raised Pavement Markers (RPMs)

Introduction

• Concept of system: PERFORMANCE

Main issues

• Lack of research in terms of durability

• Mainly empirical

• Premature wear out of the markings

• Less safer roads

7

Budget issues

Source: http://en.worldstat.info/

Finding solutions…

• New national standards:

• Materials

• Installation

• Performance: Retroreflectivity

Retroreflectivity

mcd/m2/lx

Retroreflectivity

Source: http://www.climate-charts.com

Weather issues

Rainfall

Humidity

Source: Orozco, 2007.

WEATHER CONDITIONS

Visibility issues

Literature review

Possible influencing factors:

• Type of pavement surface

• Materials and color

• Maintenance activities

• Center lines vs. border lines

• Lane width

• Types of glass beads

• Traffic (ADT)

• Weather

• Thamizharasan, Sarasua & Clarke (2002)

• Rasdorf, Zhang, Hummer & Sitzabee (2009)

• Aktan & Schnell (2004)

• Hollingsworth (2012)

• Sasidharan, Karwa & Donnell (2009)

• FHWA - USDOT (2007)

• Robertson, Sarasua, Jonhson & Davis (2012)

Literature review

• 80 road sections: Washington State

• Durability overtime: difficult to

predict

Holzschuher,

Choubane, Fletcher,

Sevearance & Lee

(2010)

Kopf (2004)

• Mobile retroreflectometer

• Variability: < 20.1

mcd/m2/lx

Methodology

Roadwayselection &

installation of markings

Measurementsites &

procedures, sampling, timings,

equipment

Retro-reflectivity

classification

Data collection

and processing

Data analysis

Road A

(University Rd.)

Road B

(N.R. 3)

Road C

(N.R. 110)

Road D

(N.R. 1)

Total length of road

section:(1)300 m 6 km 2 km 15 km

Installation of

markings:February 2012 March 2012 March 2012 May 2012

Data collection: 10 months 9 months 9 months 4 months

Pavement marking

material:

Waterborne traffic

paint

Thermoplastic

material

Solvent-borne traffic

paint

Thermoplastic &

Solvent-borne

Marking type and

color (yellow or

white):

Center line (y)

Center line (y)

Border line (w)

Symbols (w)

Center line (y)

Border line (w)

Symbols (w)

Center line (y)

Border line (w)

Symbols (w)

Road surface

condition:

Poor pavement

surface

New pavement

surface

New pavement

surface

New pavement

surface

Average Daily Traffic

(ADT):(2)N/A

22,872 (yr. 2012)

28,029 (yr. 2013)

20,982 (yr. 2012)

21,330 (yr. 2013)

78,428 (yr. 2012)

82,373 (yr. 2013)

Heavy vehicles:(2) N/A ≈ 12% ≈ 12% ≈ 14%

Study roadways

Study roadways

Material

Waterborne and solvent-borne

traffic paints

(Values in mcd/m2/lx)

Thermoplastic Material

(Values in mcd/m2/lx)

Condition White Yellow White Yellow

Very good > 200 > 150 > 400 > 300

Good 150 - 200 125 - 150 325 - 400 200 - 300

Fair 100 - 150 100 - 125 100 - 325 100 - 200

Poor < 100 < 100 < 100 < 100

Retroreflectivity

Portableretroreflectometer

Vehicle-mountedretroreflectometer

Main Results

Road A

Main Results

Road B

Main Results

Road C

Main Results

Road APortable vs. Mobile

Main Results

Traffic paints:water vs. solvent

Main Results

Solvent-based vs.Thermoplastic

Main Results

Waterborne and solvent-borne:

Yellow: 6 months

White: 8 months

Thermoplasticmaterial:

Yellow: 10 months

White: 15 months

• Experience in Costa Rica: mainly empirical

• Traffic paints: acceptable performance (rainy season)

• Thermoplastic material:

– Lower performance than expected

– 100 mcd/m2/lx → 9 months, yellow

Discussion

• Further research: weather conditions, traffic volumes,

heavy vehicles, pavement type and condition, lane width,

installation

• ASTM D7585: sampling criteria for evaluating

retroreflective pavement markings (portable)

• Longer evaluation period: 12-18 months traffic paints

and 18-24 months thermoplastic

• Survey: international experience

Next steps…

Next steps…

Poor < 100 mcd/m2/lx

Lessons learned…

• Very sensible

• Tire pressure

• Litres of fuel in the tank

• Number of passangers (Weight)

Kopf (2004)

• Changes in data collection by different crews

• Inherent variability of the equipment

• Environmental conditions…

Future Research

HVS

Road Safety Team

Thank you!

Merci beaucoup !

¡Muchas gracias!

javier.zamorarojas

@ucr.ac.cr