CMF / CRF Details

CMF ID: 7440

Add continuous auxiliary lane for weaving between entrance ramp and exit ramp


Prior Condition: No Prior Condition(s)

Category: Interchange design

Study: Guidelines for Ramp and Interchange Spacing, Ray et al., 2011

Star Quality Rating: 3 Stars   [View score details]
Crash Modification Factor (CMF)
Value: 0.79
Adjusted Standard Error:
Unadjusted Standard Error:
Crash Reduction Factor (CRF)
Value: 21   (This value indicates a decrease in crashes)
Adjusted Standard Error:
Unadjusted Standard Error:
Crash Type: All
Crash Severity: All
Roadway Types: Principal Arterial Other Freeways and Expressways
Number of Lanes:
Road Division Type:
Speed Limit:
Area Type:
Traffic Volume: Minimum of 15928 to Maximum of 104079 Annual Average Daily Traffic (AADT)
Average Traffic Volume:
Time of Day:
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: 2005 to 2007
State: WA
Type of Methodology Used: Regression cross-section
Sample Size (crashes): 5177 crashes
Other Details
Included in Highway Safety Manual? No
Date Added to Clearinghouse: Jun-22-2015
Comments: ADT range for ramps is 100 to 31,000 AADT.