CMF / CRF Details

CMF ID: 6831

Widen shoulder

Description:

Prior Condition:  Narrower paved shoulder than after condition

Category: Shoulder treatments

Study: Safety Impacts of Highway Shoulder Attributes in Illinois, Bamzai et al., 2011

 
Star Quality Rating:3 Stars  [View score details]
Rating Points Total:90
Crash Modification Factor (CMF)
Value:0.64
Adjusted Standard Error:
Unadjusted Standard Error:
Crash Reduction Factor (CRF)
Value:36  (This value indicates a decrease in crashes)
Adjusted Standard Error:
Unadjusted Standard Error:
Applicability
Crash Type:Fixed object,Head on,Run off road,Sideswipe
Crash Severity: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:All
Minimum Speed Limit:35
Maximum Speed Limit:65
Speed Unit:mph
Speed Limit Comment:
Area Type:Urban
Traffic Volume:
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 :NULL
Average Minor Road Volume :NULL
Development Details
Date Range of Data Used:2000 to 2006
Municipality:
State:IL
Country:USA
Type of Methodology Used:Before/after using empirical Bayes or full Bayes
Sample Size (crashes):NULL crashes
Sample Size (sites):NULL sites
Sample Size (site-years):NULL site-years
Sample Size (miles):NULL miles
Sample Size (mile-years):NULL mile-years
Other Details
Included in Highway Safety Manual?No
Date Added to Clearinghouse:Jun 22, 2015
Comments:This CMF applies to urban multilane highways with a combined lane width and outside paved shoulder width less than or equal to 20 ft. This CMF applies to shoulder related crashes, defined as head-on, fixed object, sideswipe opposite direction, and run-off-road.