CMF / CRF Details

CMF ID: 4242

Increase inside paved shoulder width from 4ft to 6ft

Description: Interchange influence area on urban four-lane freeway with a 6-ft inside paved shoulder and a paved outside shoulder with warning device.

Prior Condition:  4-ft paved inside shoulder and paved outside shoulder within interchange influence area

Category: Shoulder treatments

Study: Developing Crash Modification Factors for Interchange Influence Areas on Urban Four-Lane Freeways Using Multivariate Adaptive Regression Splines, Haleem, Gan, and Lu, 2012

 
Star Quality Rating:3 Stars  [View score details]
Rating Points Total:105
Crash Modification Factor (CMF)
Value:0.472
Adjusted Standard Error:
Unadjusted Standard Error:0.1
Crash Reduction Factor (CRF)
Value:52.8  (This value indicates a decrease in crashes)
Adjusted Standard Error:
Unadjusted Standard Error:10
Applicability
Crash Type:All
Crash Severity:K (fatal),A (serious injury),B (minor injury),C (possible injury)
Roadway Types:Principal Arterial Other Freeways and Expressways
Street Type:
Minimum Number of Lanes:4
Maximum Number of Lanes:4
Number of Lanes Direction:
Number of Lanes Comment:
Crash Weather:Not specified
Road Division Type:Divided by Median
Minimum Speed Limit:
Maximum Speed Limit:
Speed Unit:
Speed Limit Comment:
Area Type:Urban
Traffic Volume:
Average Traffic Volume:
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 2008
Municipality:
State:FL
Country:United States
Type of Methodology Used:Regression cross-section
Sample Size (crashes):6151 crashes
Other Details
Included in Highway Safety Manual?No
Date Added to Clearinghouse:Nov 01, 2012
Comments:Applies only to interchange influence areas. Countermeasure name changed in Jan 2014 to be more consistent with other CMFs from same study.