CMF / CRF Details
CMF ID: 9675
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: No Prior Condition(s)
Category: Shoulder treatments
Study: Safety Evaluation of The Safetyedge Treatment for Pavement Edge Drop-Offs on Two-Lane Rural Roads, Lyon et al., 2018
Star Quality Rating: | [View score details] |
Rating Points Total: | 140 |
Crash Modification Factor (CMF) | |
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Value: | 0.764 |
Adjusted Standard Error: | |
Unadjusted Standard Error: | 0.057 |
Crash Reduction Factor (CRF) | |
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Value: | 23.6 (This value indicates a decrease in crashes) |
Adjusted Standard Error: | |
Unadjusted Standard Error: | 5.7 |
Applicability | |
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Crash Type: | Run off road |
Crash Severity: | All |
Roadway Types: | Not specified |
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: | Undivided |
Minimum Speed Limit: | |
Maximum Speed Limit: | |
Speed Unit: | |
Speed Limit Comment: | |
Area Type: | Rural |
Traffic Volume: | |
Average Traffic Volume: | 3697 Annual Average Daily Traffic (AADT) |
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 | |
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Date Range of Data Used: | 2005 to 2015 |
Municipality: | FL-Marion County only |
State: | FL,IA,NC,OH,PA |
Country: | USA |
Type of Methodology Used: | Before/after using empirical Bayes or full Bayes |
Sample Size (crashes): | 236 crashes after |
Sample Size (sites): | 737 sites before, 737 sites after |
Other Details | |
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Included in Highway Safety Manual? | No |
Date Added to Clearinghouse: | Oct 27, 2018 |
Comments: | CMF for sites with travel lane width (two lanes)=21-24ft |