Study Details

Study Title: Separated Bike Lane Crash Analysis

Authors: Rothenberg et al.

Publication Date: 2016

Abstract: 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.

Study Citation: Rothenberg, H., D. Goodman, and C. Sundstrom, "Separated Bike Lane Crash Analysis." Presented at the 95th Annual Meeting of the Transportation Research Board, Washington, D.C., (2016).


CMFs Associated With This Study

Category: Bicyclists

Countermeasure: Install separated bicycle lane

CMF CRF(%) Quality Crash Type Crash Severity Roadway Type Area Type
1.515 -51.5 2 Stars Vehicle/bicycle All Not specified Not specified
1.535 -53.5 2 Stars Vehicle/bicycle All Not specified Not specified
0.842 15.8 2 Stars Vehicle/bicycle All Not specified Not specified
1.366 -36.6 2 Stars Vehicle/bicycle All Not specified Not specified
2.444 -144.4 2 Stars Vehicle/bicycle All Not specified Not specified
1.557 -55.7 2 Stars Vehicle/bicycle All Not specified Not specified
4 -300 0 Stars Vehicle/bicycle All Not specified Not specified
1.369 -36.9 2 Stars Vehicle/bicycle All Not specified Not specified
0 100 1 Star Vehicle/bicycle All Not specified Not specified
1.307 -30.7 2 Stars Vehicle/bicycle All Not specified Not specified
6.667 -566.7 1 Star Vehicle/bicycle All Not specified Not specified
2.2 -120 1 Star Vehicle/bicycle All Not specified Not specified
1.308 -30.8 2 Stars Vehicle/bicycle All Not specified Not specified
1.391 -39.1 2 Stars Vehicle/bicycle All Not specified Not specified
1.523 -52.3 2 Stars Vehicle/bicycle All Not specified Not specified
1.672 -67.2 1 Star Vehicle/bicycle All Not specified Not specified
1.113 -11.3 2 Stars Vehicle/bicycle All Not specified Not specified
1.402 -40.2 2 Stars Vehicle/bicycle All Not specified Not specified
1.737 -73.7 2 Stars Vehicle/bicycle All Not specified Not specified
1.558 -55.8 2 Stars Vehicle/bicycle All Not specified Not specified
1.456 -45.6 2 Stars Vehicle/bicycle All Not specified Not specified
1.011 -1.1 2 Stars All All Not specified Not specified
0.714 28.6 2 Stars All All Not specified Not specified
0.687 31.3 2 Stars All All Not specified Not specified
0.741 25.9 2 Stars All All Not specified Not specified
1.301 -30.1 2 Stars All All Not specified Not specified
0.908 9.2 2 Stars All All Not specified Not specified
0.928 7.2 0 Stars All All Not specified Not specified
1.369 -36.9 2 Stars All All Not specified Not specified
0.858 14.2 2 Stars All All Not specified Not specified
0.816 18.4 1 Star All All Not specified Not specified
1.137 -13.7 2 Stars All All Not specified Not specified
0.828 17.2 2 Stars All All Not specified Not specified
0.951 4.9 2 Stars All All Not specified Not specified
0.918 8.2 2 Stars All All Not specified Not specified
0.94 6 2 Stars All All Not specified Not specified
0.839 16.1 2 Stars All All Not specified Not specified
0.858 14.2 2 Stars All All Not specified Not specified
1.359 -35.9 2 Stars All All Not specified Not specified
0.918 8.2 2 Stars All All Not specified Not specified
0.963 3.7 2 Stars All All Not specified Not specified

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