CMF / CRF Details

CMF ID: 9217

Install safety edge treatment

Description: The safety edge is a low-cost treatment that is implemented in conjunction with pavement resurfacing and is intended to help minimize drop-off-related crashes.

Prior Condition:  Drop-off pavement edge

Category: Shoulder treatments

Study: Development Of Crash Modification Factors For The Application Of The Safetyedge Treatment On Two-Lane Rural Roads, Donnell et al., 2017

 
Star Quality Rating:5 Stars  [View score details]
Rating Points Total:140
Crash Modification Factor (CMF)
Value:0.813
Adjusted Standard Error:
Unadjusted Standard Error:0.076
Crash Reduction Factor (CRF)
Value:18.7  (This value indicates a decrease in crashes)
Adjusted Standard Error:
Unadjusted Standard Error:7.6
Applicability
Crash Type:Head on
Crash Severity:All
Roadway Types:Principal Arterial Other
Street Type:
Minimum Number of Lanes:2
Maximum Number of Lanes:2
Number of Lanes Direction:
Number of Lanes Comment:
Crash Weather:Not specified
Road Division Type:
Minimum Speed Limit:
Maximum Speed Limit:
Speed Unit:
Speed Limit Comment:
Area Type:Rural
Traffic Volume:Minimum of 10 to Maximum of 18600 Annual Average Daily Traffic (AADT)
Average Traffic Volume:3175 Annual Average Daily Traffic (AADT)
Time of Day:Not specified
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:2005 to 2014
Municipality:
State:FL,IA,NC,OH,PA
Country:
Type of Methodology Used:Before/after using empirical Bayes or full Bayes
Sample Size (crashes):518 crashes before, 155 crashes after
Sample Size (sites):1663 sites before, 1663 sites after
Sample Size (miles):1321 miles before, 1321 miles after
Sample Size (miles):7467 mile-years before, 2958 mile-years after
Other Details
Included in Highway Safety Manual?No
Date Added to Clearinghouse:Jun 17, 2018
Comments:Excludes intersection-related crashes and animal-related crashes.