Estimating Crash Modification Factors for Lane Departure Countermeasures in Kansas

Project Details
STATUS

Completed

START DATE

08/15/15

END DATE

12/29/17

FOCUS AREAS

Safety

RESEARCH CENTERS InTrans, CTRE, MTC
SPONSORS

Kansas Department of Transportation
Midwest Transportation Center
USDOT/OST-R

Researchers
Principal Investigator
Sunanda Dissanayake

Kansas State University

Co-Principal Investigator
Shauna Hallmark

Director, InTrans

About the research

This project was conducted to estimate crash modification factors (CMFs) for lane departure countermeasures in Kansas. Cross-sectional, case-control, and before-and-after empirical Bayes (EB) methods were employed. Results showed that centerline rumble strips on rural two-lane road segments have crash-reduction effects on all lane departure and fatal and injury lane departure crashes on both tangent and curved road segments. Shoulder rumble strips were effective in reducing all lane departure and fatal and injury lane departure crashes on tangent road segments but showed less effectiveness on curved road segments. The combination of centerline and shoulder rumble strips showed significant safety effectiveness on both tangent and curved road segments.

Shoulder rumble strips on four-lane road segments also showed crash-reduction effects on all lane departure and fatal and injury lane departure crashes on both tangent and curved road segments. Cable median barriers showed a crash-reduction effect on all lane departure crashes, and fatal and injury lane departure crashes on four-lane divided road segments. Chevrons and post-mounted delineators also showed effectiveness on both all lane departure crashes and fatal and injury lane departure crashes. The safety edge treatment also showed a crash-reduction effect on all lane departure crashes and fatal and injury lane departure crashes.

Finally, all models were validated to check for accuracy. Models developed for the cross-sectional method were validated using mean square error and mean of the residuals. Case-control models were validated using the specificity, accuracy, and sensitivity of the models. The significance of the CMFs developed using the before-and-after EB method was realized using the method given in the Highway Safety Manual.


Funding Sources:
Kansas Department of Transportation ($50,000.00)
Midwest Transportation Center
USDOT/OST-R ($50,000.00)
Total: $100,000.00

Contract Number: DTRT13-G-UTC37

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