The Effectiveness of Wider Edge Line Pavement Markings

February 2012

Sponsored by: AGBMA

Wider Lines Synthesis, 2002

• Included:– US practices– International practices– Review of literature– Suggestions for research

Terminology

• Standard edge line width = 4 inch– The standard for over 60 years

• Wider edge line width = 6 inches– A recently proven low-cost safety countermeasure

Adding a 4-inch Edge Line

• Benefit/cost ratio of 60:1 (Miller)

What happens if we increase the width of the edge lines?

Prior to 2011…

New findings released in 2011 at June NCUTCD

Safety Effects of Wider Edge Lines on Rural, Two-Lane Roads

Publications

• FHWA Final Report– Submitted Dec 31, 2011– In publication office

• Journal Accident & Analysis Prevention– Paper accepted in January 2012– Current in press

Summary of Safety EffectsCrash Type Percent ReductionTotal 15.0 – 30.1Fatal and Injury 15.4 – 37.7Day 12.0 – 29.1Night -2.4 – 30.7

• Kansas from 2001-2007, almost 1300 miles• Michigan from 2001-2009, 787.8 miles• Illinois from 2001-2006, 287 miles

Comparative B/C Analysis

• Used disaggregated fatal and injury crash reduction findings from Kansas data

• Used crash cost values from NHTSA inflated to 2011 dollars

• Assumed 22 of injuries were disabling injuries and 78 were minor injuries

• Assumed waterborne paint: – $0.15 per foot for 6-in markings– 2 year service life

FindingsTreatment B/C RatioWider Edge Lines $33 - $55 per $1Rumble Strips $37 - $46 per $1Chevrons $9 - $46 per $1RRPMs $13 per $1

QuestionsPaul J Carlson, Ph.D., P.E.Texas Transportation Institute979-845-1728paul-carlson@tamu.edu