CMF / CRF Details

CMF ID: 4968

Convert a 2 ft. turf shoulder to a 10 ft. paved shoulder (bituminous base)

Description: Convert a 2 ft. turf shoulder to a 10 ft. paved shoulder (bituminous base)

Prior Condition: 2 ft. turf shoulder

Category: Shoulder treatments

Study: Safety Effectiveness of Various Types of Shoulders on Rural Two-Lane Roads in Winter and Non-Winter Periods, Zeng and Schrock, 2013

Star Quality Rating: 3 Stars   [View score details]
Rating Points Total: 105
Crash Modification Factor (CMF)
Value: 0.84
Adjusted Standard Error:
Unadjusted Standard Error: 0.038
Crash Reduction Factor (CRF)
Value: 16   (This value indicates a decrease in crashes)
Adjusted Standard Error:
Unadjusted Standard Error: 3.8
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:
Minimum Speed Limit:
Maximum Speed Limit:
Speed Unit:
Speed Limit Comment:
Area Type: Rural
Traffic Volume:
Average Traffic Volume: 3535 Annual Average Daily Traffic (AADT)
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: 2003 to 2007
State: KS
Country: USA
Type of Methodology Used: Regression cross-section
Sample Size (crashes): 3091 crashes
Other Details
Included in Highway Safety Manual? No
Date Added to Clearinghouse: Aug-01-2013
Comments: CMF represents winter period crashes only. Study assumes a 6 month winter period from October 16 through April 15.CMF is significant at the 0.05 level.