CMF / CRF Details

CMF ID: 884

Reduce shoulder width (6 ft to 2 ft)


Prior Condition: No Prior Condition(s)

Category: Shoulder treatments

Study: Estimation of Safety Effectiveness of Changes in Shoulder Width using Case-Control and Cohort Methods, Gross and Jovanis, 2007

Star Quality Rating: 3 Stars   [View score details]
Rating Points Total: 105
Crash Modification Factor (CMF)
Value: 1.11
Adjusted Standard Error:
Unadjusted Standard Error: 0.024
Crash Reduction Factor (CRF)
Value: -11   (This value indicates an increase in crashes)
Adjusted Standard Error:
Unadjusted Standard Error: 2.4
Crash Type: All
Crash Severity: All
Roadway Types: Not specified
Street Type:
Minimum Number of Lanes: 2
Maximum Number of Lanes: 2
Number of Lanes Direction:
Number of Lanes Comment:
Crash Weather: Not specified
Road Division Type: Undivided
Minimum Speed Limit:
Maximum Speed Limit:
Speed Unit:
Speed Limit Comment:
Area Type: Rural
Traffic Volume: Minimum of 95 to Maximum of 25844
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: 1997 to 2001
State: PA
Type of Methodology Used: Regression cross-section
Sample Size (sites): 21646 sites
Other Details
Included in Highway Safety Manual? No
Date Added to Clearinghouse: Dec-01-2009