Study Details
Study Title: Estimation of bicycle crash modification factors (CMFs) on urban facilities using zero inflated negative binomial models
Authors: Raihan et al.
Publication Date: FEB, 2019
Abstract: The objective of this study was to develop crash modification factors (CMFs) for bicycle crashes for different roadway segment and intersection facility types in urban areas. The study used four years (2011–2014) of crash data from Florida to quantify the safety impacts of roadway and traffic characteristics, bicycle infrastructure, and bicycle activity data on bicycle crashes. A cross-sectional analysis using Generalized Linear Model (GLM) approach with Zero Inflated Negative Binomial (ZINB) distribution was adopted to develop the relevant regression models in this study. Lane width, speed limit, and grass in the median were observed to have positive impacts on reducing bicycle crashes. On the contrary, presence of sidewalk and sidewalk barrier were found to increase the bicycle crash probabilities. Increased bicycle activity was found to reduce the bicycle crash probabilities on segments, while increased bicycle activity resulted in higher bicycle crash probabilities at intersections. Bus stops were found to increase the bicycle crash probabilities at intersections, whereas, protected signal control had a positive impact on bicycle safety. This research provides a greater insight into how various characteristics
affect bicycle safety, a topic that is seldom considered by researchers and practitioners.
Study Citation: Raihan, M.A., P. Alluri, W. Wu, and A. Gan. "Estimation of bicycle crash modification factors (CMFs) on urban facilities using zero inflated negative binomial models". Accident Analysis and Prevention, Vol. 123, (2019), pp. 303-313.
Study Report: Download the Study Report Document
CMFs Associated With This Study
Category: Bicyclists
Countermeasure: Install sidewalk barrier
| CMF | CRF(%) | Quality | Crash Type | Crash Severity | Roadway Type | Area Type |
|---|
| 1.83 | -83 |  | Vehicle/bicycle | All | Not specified | Urban |
Category:Intersection traffic control
Countermeasure: Provide protected left-turn phase
| CMF | CRF(%) | Quality | Crash Type | Crash Severity | Roadway Type | Area Type |
|---|
| 0.69 | 31 | | Vehicle/bicycle | All | Not specified | Urban |
Category:Pedestrians
Countermeasure: Install sidewalk
| CMF | CRF(%) | Quality | Crash Type | Crash Severity | Roadway Type | Area Type |
|---|
| 1.53 | -53 | | Vehicle/bicycle | All | Not specified | Urban |
| 3.09 | -209 | | Vehicle/bicycle | All | Not specified | Urban |
Category:Roadside
Countermeasure: Change median from paved to grass
| CMF | CRF(%) | Quality | Crash Type | Crash Severity | Roadway Type | Area Type |
|---|
| 0.72 | 28 | | Vehicle/bicycle | All | Not specified | Urban |
| 0.7 | 30 | | Vehicle/bicycle | All | Not specified | Urban |
Countermeasure: Change paved median to raised traffic separator
| CMF | CRF(%) | Quality | Crash Type | Crash Severity | Roadway Type | Area Type |
|---|
| 1.27 | -27 | | Vehicle/bicycle | All | Not specified | Urban |
Category:Roadway
Countermeasure: Change lane width from X to Y (in feet)
| CMF | CRF(%) | Quality | Crash Type | Crash Severity | Roadway Type | Area Type |
|---|
 | | | Vehicle/bicycle | All | Not specified | Urban |
| | | Vehicle/bicycle | All | Not specified | Urban |
Countermeasure: Reduce lane width from 12 ft to less than 12 ft
| CMF | CRF(%) | Quality | Crash Type | Crash Severity | Roadway Type | Area Type |
|---|
| 1.72 | -72 |  | Vehicle/bicycle | All | Not specified | Urban |
| 1.25 | -25 | | Vehicle/bicycle | All | Not specified | Urban |
Category:Shoulder treatments
Countermeasure: Convert from paved shoulder to other
| CMF | CRF(%) | Quality | Crash Type | Crash Severity | Roadway Type | Area Type |
|---|
| 0.48 | 52 | | Vehicle/bicycle | All | Not specified | Urban |
Countermeasure: Convert paved shoulder to curb and gutter
| CMF | CRF(%) | Quality | Crash Type | Crash Severity | Roadway Type | Area Type |
|---|
| 1.21 | -21 | | Vehicle/bicycle | All | Not specified | Urban |
Category:Speed management
Countermeasure: Change posted speed limit from X MPH to Y MPH
| CMF | CRF(%) | Quality | Crash Type | Crash Severity | Roadway Type | Area Type |
|---|
| | | Vehicle/bicycle | All | Not specified | Urban |
| | | Vehicle/bicycle | All | Not specified | Urban |
| | | Vehicle/bicycle | All | Not specified | Urban |
| | | Vehicle/bicycle | All | Not specified | Urban |
