CMF / CRF Details

CMF ID: 5351

Reduce paved shoulder from 3 ft to 1 ft

Description: Reduce shoulder from 3 ft to 1 ft

Prior Condition: Shoulder width 3 ft

Category: Shoulder treatments

Study: Safety Effects of Lane Width and Shoulder Width on Two-Lane Rural State Highways in Idaho, Abdel-Rahim and Sonnen, 2012

Star Quality Rating: 3 Stars   [View score details]
Crash Modification Factor (CMF)
Value: 1.11
Adjusted Standard Error:
Unadjusted Standard Error:
Crash Reduction Factor (CRF)
Value: -11   (This value indicates an increase in crashes)
Adjusted Standard Error:
Unadjusted Standard Error:
Crash Type: All
Crash Severity: All
Roadway Types: Not specified
Number of Lanes: 2
Road Division Type: Undivided
Speed Limit:
Area Type: Rural
Traffic Volume: Minimum of 186 to Maximum of 400 Annual Average Daily Traffic (AADT)
Average Traffic Volume: 243 Annual Average Daily Traffic (AADT)
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: 1993 to 2010
State: ID
Country: USA
Type of Methodology Used: Regression cross-section
Sample Size (crashes): 7977 crashes
Other Details
Included in Highway Safety Manual? No
Date Added to Clearinghouse: Jan-09-2014