01123183

Component

https://doi.org/10.3141/2103-06

http://scholar.google.com...cles&publication_year=2009

There is a need to evaluate low-cost safety strategies that states may implement as part of their Strategic Highway Safety Plan. FHWA organized a pooled fund study of 26 states to evaluate several low-cost safety strategies, including the reallocation of total paved width. This study identifies whether it is safer to increase lane width or increase shoulder width given a fixed total width. Geometric, traffic, and crash data were obtained for more than 52,000 mi of roadway in Pennsylvania and Washington State. A case-control approach was applied to evaluate the safety effectiveness of various lane–shoulder configurations. There was a general reduction in the odds ratio as total paved width, lane width, and shoulder width increased individually; this is consistent with previous research. However, the primary research objective was to estimate the safety effectiveness of reallocating a fixed total paved width. Individual state results did not indicate a clear trade-off between lane and shoulder width for a fixed total width. Supplementing the results of this study with previous research, crash modification factors (CMFs) are provided for several lane–shoulder combinations. The selected values present a more apparent trade-off, indicating a slight benefit to increasing lane width for a fixed total width. Importantly, the results differ from other studies that developed CMFs without considering the interaction between lane and shoulder width, including those studies currently referenced in the "Highway Safety Manual." This raises the question of whether CMFs should reflect the interaction between lane and shoulder width.

01138796

09-1294

English

pp 42-49

2009

Transportation Research Record: Journal of the Transportation Research Board

9780309126182

Print

Figures (1) ; References (23) ; Tables (4)

Crash data; Crash modification factors; Highway safety; Paved shoulders; Road shoulders; Rural highways; Two lane highways

Highway Safety Manual; Strategic Highway Safety Plan

Lane width; Shoulder width; Undivided highways

Pennsylvania; Washington (State)

Highways; Safety and Human Factors; I82: Accidents and Transport Infrastructure

TRIS, TRB, ATRI

Jan 30 2009 5:31PM

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