CMF / CRF Details

CMF ID: 7761

Widen shoulder

Description:

Prior Condition: Roadways with narrow shoulders

Category: Shoulder treatments

Study: Validation and Application of Highway Safety Manual (Part D) in Florida, Abdel-Aty et al., 2014

 
Star Quality Rating: 3 Stars   [View score details]
Crash Modification Factor (CMF)
Value: 0.39
Adjusted Standard Error:
Unadjusted Standard Error: 0.19
Crash Reduction Factor (CRF)
Value: 61   (This value indicates a decrease in crashes)
Adjusted Standard Error:
Unadjusted Standard Error: 19
Applicability
Crash Type: Run off road
Crash Severity: K (fatal),A (serious injury),B (minor injury),C (possible injury)
Roadway Types: Not specified
Number of Lanes: >2
Road Division Type: All
Speed Limit: 65-70
Area Type: Rural
Traffic Volume: Minimum of 2000 to Maximum of 50000 Annual Average Daily Traffic (AADT)
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: 2005 to 2010
Municipality:
State: FL
Country: USA
Type of Methodology Used: Before/after using empirical Bayes or full Bayes
Sample Size (sites): 15 sites before, 15 sites after
Sample Size (site-years): 30 site-years before, 30 site-years after
Other Details
Included in Highway Safety Manual? No
Date Added to Clearinghouse: Mar-08-2016
Comments: CMFs of widening shoulder width on rural multi-lane highways apply to single-vehicle run-off-road crashes