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]
Crash Modification Factor (CMF)
Value: 1.304
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
Number of Lanes: 4
Road Division Type: Divided by Median
Speed Limit:
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
State: CA, MO, NC, OH, PA, WA
Country: USA
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.