Paper Details

TRB 91st Annual Meeting (January 22-26, 2012)

Event Number:	648
Event Title:	Highway Safety Performance
Event Date:	Jan 24 2012 7:30PM- 9:30PM
Event Location:	Marriott, Salon 2
Event Description:
Event Agenda:

Developing Lane-Width Crash Modification Factors for Urban Multilane Roadways with Curb-and-Gutter and Asymmetric Lanes (12-0076)

This study developed lane width crash modification factors (CMFs) for urban curb-and-gutter multilane roadways with asymmetric lanes, i.e., outside lane wider than inside lane. The roadway segments used were urban four-lane with a raised median (4D) and with a two-way left-turn lane (5T). Data used included 25 centerline miles of 5T segments and 39 centerline miles of 4D segments. Three crash categories were evaluated; KABCO { Fatal (K), incapacitating-injury (A), non-incapacitating injury (B), possible injury (C) and property damage only crashes (O)}, KABC {Fatal (K), incapacitating-injury (A), non-incapacitating injury (B), and possible injury crashes (C)}, and PDO (property damage only) crashes. A cross-sectional method was used as it was the most practical and feasible for this study. Six-year (2004 to 2009) of segment crashes were examined. The analysis involved statistical modeling using the negative binomial model, whose coefficients were used to develop multiplicative CMF equations for a combined effect of variable inside and outside lane width. In summary, the results show that reducing the inside lane width from 12 ft to 11 ft does not affect estimated crash frequency of 4D segments for all three crash categories, and PDO crashes for 5T segments. However, narrowing the inside lane width appears to be associated with increased estimated KABCO and KABC crashes for 5T sections. The results also suggest that widening the outside lane from the baseline 12 ft causes a reduction in estimated crash frequency for all three crash categories (KABCO, KABC, and PDO) for both 4D and 5T segments.

Authors
     Mbatta, Geophrey , Florida A&M University - Florida State University
     Sando, Thobias , University of North Florida
     Moses, Ren , Florida A&M University - Florida State University