CMF / CRF Details

CMF ID: 4521

Increasing the outside shoulder width inside the work zone by one foot

Description: Increasing the outside shoulder width inside the work zone by one foot

Prior Condition:  Regular traffic conditions without work zone

Category: Work zone

Study: Improving Safety in High-Speed Work Zones: A Super 70 Study, Tarko, Andrew P.; Bin Islam, Mouyid ; Thomaz, Jose E., 2011

Star Quality Rating:5 Stars  [View score details]
Rating Points Total:135
Crash Modification Factor (CMF)
Adjusted Standard Error:
Unadjusted Standard Error:0.02
Crash Reduction Factor (CRF)
Value:-4.3  (This value indicates an increase in crashes)
Adjusted Standard Error:
Unadjusted Standard Error:2
Crash Type:Single vehicle
Crash Severity:All
Roadway Types:Principal Arterial Interstate
Street Type:
Minimum Number of Lanes:
Maximum Number of Lanes:
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:2006 to 2008
Type of Methodology Used:Regression cross-section
Sample Size (crashes):373 crashes
Other Details
Included in Highway Safety Manual?No
Date Added to Clearinghouse:Dec 06, 2012
Comments:CMF identified from Appendix I