CMF / CRF Details

CMF ID: 6957

Provide on-ramp

Description: Presence of on-ramp

Prior Condition:  No on-ramp present

Category: Access management

Study: NCHRP Report 794: Median Cross-Section Design for Rural Divided Highways, Graham et al., 2014

Star Quality Rating:4 Stars  [View score details]
Rating Points Total:115
Crash Modification Factor (CMF)
Adjusted Standard Error:
Unadjusted Standard Error:0.085
Crash Reduction Factor (CRF)
Value:-30.4  (This value indicates an increase in crashes)
Adjusted Standard Error:
Unadjusted Standard Error:8.5
Crash Type:Cross median,Fixed object,Run off road,Other
Crash Severity:All
Roadway Types:Principal Arterial Other Freeways and Expressways
Street Type:
Minimum Number of Lanes:4
Maximum Number of Lanes:4
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:Rural
Traffic Volume:
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:2000 to 2007
Type of Methodology Used:Regression cross-section
Sample Size (miles):1621 miles
Other Details
Included in Highway Safety Manual?No
Date Added to Clearinghouse:Nov 01, 2015
Comments:This CMF applies to the presence of an on-ramp for median-related crashes on four-lane freeways with traversable medians. Median-related crashes include rollover, non-barrier fixed-object, vehicle coming to rest in median, vehicle departing and returning to traveled way, and cross-median crashes.