CMF / CRF Details

CMF ID: 10283

Install safety edge treatment with 1-2 ft. lane widening


Prior Condition: No Prior Condition(s)

Category: Shoulder treatments

Study: An Alternative Regression-Based Approach to Estimate the Crash Modification Factors of Multiple Treatments Using Before-and-After Data, Galgamuwa, U. and S. Dissanayake., 2018

Star Quality Rating: 3 Stars   [View score details]
Crash Modification Factor (CMF)
Value: 0.51
Adjusted Standard Error:
Unadjusted Standard Error: 0.115
Crash Reduction Factor (CRF)
Value: 49   (This value indicates a decrease in crashes)
Adjusted Standard Error:
Unadjusted Standard Error: 11.5
Crash Type: All
Crash Severity: All
Roadway Types: All
Number of Lanes:
Road Division Type:
Speed Limit:
Area Type: All
Traffic Volume:
Average Traffic Volume:
Time of Day: All
If countermeasure is intersection-based
Intersection Type:
Intersection Geometry:
Traffic Control:
Major Road Traffic Volume:
Minor Road Traffic Volume:
Average Major Road Volume :
Average Minor Road Volume :
Development Details
Date Range of Data Used: 2009 to 2014
State: KS
Type of Methodology Used: Before/after using empirical Bayes or full Bayes
Sample Size (crashes): 29 crashes after
Sample Size (miles): 72 miles before, 72 miles after
Other Details
Included in Highway Safety Manual? No
Date Added to Clearinghouse: Dec-07-2019
Comments: This is a combined CMF for multiple treatments.