CMF / CRF Details

CMF ID: 6660

Widen shoulder

Description:

Prior Condition: Original shoulder width 4-12 ft

Category: Shoulder treatments

Study: Exploration and comparison of crash modification factors for multiple treatments on rural multilane roadways, Park et al., 2014

 
Star Quality Rating: 4 Stars   [View score details]
Rating Points Total: 130
Crash Modification Factor (CMF)
Value: 0.566
Adjusted Standard Error:
Unadjusted Standard Error: 0.191
Crash Reduction Factor (CRF)
Value: 43.4   (This value indicates a decrease in crashes)
Adjusted Standard Error:
Unadjusted Standard Error: 19.1
Applicability
Crash Type: Run off road,Single vehicle
Crash Severity: K (fatal),A (serious injury),B (minor injury),C (possible injury)
Roadway Types: Not specified
Street Type:
Minimum Number of Lanes: 3
Maximum Number of Lanes:
Number of Lanes Direction: Both Directions
Number of Lanes Comment: Multi Lane
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 2000 to Maximum of 50000 Annual Average Daily Traffic (AADT)
Average Traffic Volume:
Time of Day:
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: 2003 to 2012
Municipality:
State: FL
Country:
Type of Methodology Used: Before/after using empirical Bayes or full Bayes
Sample Size (miles): 463150 miles before
Other Details
Included in Highway Safety Manual? No
Date Added to Clearinghouse: Jun-22-2015
Comments: Before condition shoulder width between 4-12 ft The number of crashes in the after period were not reported in this study, however, they have been recorded as 300 to give 10 points as a beneift of doubt for one or more of the following: (1) number of miles/sites in the reference/treatment group, (2) number of crashes in the references/treatment group, (3) reporting AADTs for the aggregate dataset but not for the disaggragate dataset used for CMF development.