01588674

Component

This paper highlights the methodology and results of a safety data analysis undertaken as part of the study process for the Federal Highway Administration’s (FHWA) Separated Bike Lane Planning and Design Guide. It outlines challenges and recommends a data collection framework that will lead to a better understanding of the full volume and safety picture for separated bike lanes. This study evaluated 18 sites before and after the installation of separated bike lanes. Of the 18 sites, 14 locations had data on both total crashes and bicycle crashes. Eight of these locations saw a decrease in total crashes and five sites saw a decrease in bicycle crashes. This translates to nine of 14 sites demonstrating a decrease in crashes of some sort. Four of the 14 sites saw decreases in both bicycle and total crashes. Similar trends are seen when considering bicycle exposure at sites with at least four average annual bicycle crashes. Five of the 10 sites saw decreases in average annual bicycle crashes per average hourly bicycle volume. It appears that the introduction of separated bike lanes may result in increased challenges at intersections. All six of the sites where the analysis included consideration of intersection vs. midblock crashes saw an increase in the percentage of crashes that occurred at an intersection. This was true for bicycle crashes as well as those not involving a bicycle. However, these comparisons did not control for changes in bicycle volumes between the before and after periods. There are significant data limitations to this study. In particular, challenges associated with obtaining bicycle volume data (both before and after) make it difficult to understand the true impacts on safety of separated bike lanes. Also, the small number of bicycle crashes occurring at these locations yield analysis results with very large percentage changes (increases or decreases) since a change of one or two crashes can effectively double or triple the crash count for that site. It is critical that this data is collected so that future studies may evaluate the safety of separated bike lanes under different conditions and designs in greater detail. For this reason, a recommended minimum data collection approach is presented in this paper to, over time, improve the quantity and quality of data on separated bike lanes.

This paper was sponsored by TRB committee ANF20 Standing Committee on Bicycle Transportation.

01584066

16-4289

English

17p

2016

Transportation Research Board 95th Annual Meeting

Digital/other

References; Tables

Bicycle crashes; Bicycle lanes; Safety; Separators; Traffic volume

U.S. Federal Highway Administration

Pedestrians and Bicyclists; Planning and Forecasting; Safety and Human Factors; I72: Traffic and Transport Planning; I83: Accidents and the Human Factor

Transportation Research Board Annual Meeting 2016 Paper #16-4289

PRP, TRIS, TRB, ATRI

Jan 12 2016 5:53PM