Study Details

Study Title: Applying Bayesian Hierarchical Models to Examine Motorcycle Crashes at Signalized Intersections

Authors: Haque et al.

Publication Date: JAN, 2010

Abstract: Motorcycles are overrepresented in road traffic crashes and particularly vulnerable at signalized intersections. The objective of this study is to identify causal factors affecting the motorcycle crashes at both four-legged and T signalized intersections. Treating the data in time-series cross-section panels, this study explores different Hierarchical Poisson models and found that the model allowing autoregressive lag-1 dependence specification in the error term is the most suitable. Results show that the number of lanes at the four-legged signalized intersections significantly increases motorcycle crashes largely because of the higher exposure resulting from higher motorcycle accumulation at the stop line. Furthermore, the presence of a wide median and an uncontrolled left-turn lane at major roadways of four-legged intersections exacerbate this potential hazard. For T signalized intersections, the presence of exclusive right-turn lane at both major and minor roadways and an uncontrolled left-turn lane at major roadways increases motorcycle crashes. Motorcycle crashes increase on high-speed roadways because they are more vulnerable and less likely to react in time during conflicts. The presence of red light cameras reduces motorcycle crashes significantly for both four-legged and T intersections. With the red light camera, motorcycles are less exposed to conflicts because it is observed that they are more disciplined in queuing at the stop line and less likely to jump start at the start of green.

Study Citation: Haque, M. M., Chin, H. C., and Huang, H., "Applying Bayesian Hierarchical Models to Examine Motorcycle Crashes at Signalized Intersections." Accident Analysis and Prevention, Vol. 42, No. 1, Elsevier Ltd, (2010) pp. 203-212.


CMFs Associated With This Study

Category: Access management

Countermeasure: Install wide median (>2 m) on major road of a 4-leg signalized intersection (motorcycle crashes)

CMF CRF(%) Quality Crash Type Crash Severity Roadway Type Area Type
1.2 -20 3 Stars All All Not Specified Urban

Category:Advanced technology and ITS

Countermeasure: Install red-light camera on major road of a 4-leg intersection (motorcycle crashes)

CMF CRF(%) Quality Crash Type Crash Severity Roadway Type Area Type
0.63 37 3 Stars All All Not Specified Urban

Countermeasure: Install red-light camera on major road of a T intersection (motorcycle crashes)

CMF CRF(%) Quality Crash Type Crash Severity Roadway Type Area Type
0.45 55 3 Stars All All Not Specified Urban

Countermeasure: Install red-light camera on minor road of a 4-leg intersection (motorcycle crashes)

CMF CRF(%) Quality Crash Type Crash Severity Roadway Type Area Type
0.75 25 3 Stars All All Not Specified Urban

Category:Intersection geometry

Countermeasure: Change number of lanes on major road of a 4-leg signalized intersection from X to Y (motorcycle crashes)

CMF CRF(%) Quality Crash Type Crash Severity Roadway Type Area Type
CMF Equation CRF Equation 3 Stars All All Not Specified Urban

Countermeasure: Change number of lanes on minor road of a 4-leg signalized intersection from X to Y (motorcycle crashes)

CMF CRF(%) Quality Crash Type Crash Severity Roadway Type Area Type
CMF Equation CRF Equation 3 Stars All All Not Specified Urban

Countermeasure: Change number of lanes on minor road of a signalized T intersection (motorcycle crashes)

CMF CRF(%) Quality Crash Type Crash Severity Roadway Type Area Type
CMF Equation CRF Equation 3 Stars All All Not Specified Urban

Countermeasure: Install right-turn lane on minor road of a signalized T intersection (motorcycle crashes)

CMF CRF(%) Quality Crash Type Crash Severity Roadway Type Area Type
1.6 -60 3 Stars All All Not Specified Urban

Countermeasure: Install right-turn lanes on major road of a signalized T intersection (motorcycle crashes)

CMF CRF(%) Quality Crash Type Crash Severity Roadway Type Area Type
2.5 -150 3 Stars All All Not Specified Urban

Countermeasure: Install uncontrolled left-turn lane on major road of a 4-leg signalized intersection (motorcycle crashes)

CMF CRF(%) Quality Crash Type Crash Severity Roadway Type Area Type
1.23 -23 3 Stars All All Not Specified Urban

Countermeasure: Install uncontrolled left-turn lane on major road of a signalized T intersection (motorcycle crashes)

CMF CRF(%) Quality Crash Type Crash Severity Roadway Type Area Type
1.4 -40 3 Stars All All Not Specified Urban

Category:Roadway

Countermeasure: Convert major road of a signalized T intersection from two-way to one-way (motorcycle crashes)

CMF CRF(%) Quality Crash Type Crash Severity Roadway Type Area Type
0.4 60 3 Stars All All Not Specified Urban

Category:Speed management

Countermeasure: Increase speed limit of major road of a 4-leg signalized intersection from less than 50 km/h to greater than or equal to 50 km/h (motorcycle crashes)

CMF CRF(%) Quality Crash Type Crash Severity Roadway Type Area Type
2.19 -119 3 Stars All All Not Specified Urban

Countermeasure: Increase speed limit of minor road of a signalized T intersection from less than 50 km/h to greater than or equal to 50 km/h (motorcycle crashes)

CMF CRF(%) Quality Crash Type Crash Severity Roadway Type Area Type
3.57 -257 3 Stars All All Not Specified Urban