diapositiva 1€¦ · title: diapositiva 1 author: jzamora created date: 6/12/2014 3:50:09 pm
TRANSCRIPT
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