CMF / CRF Details

CMF ID: 6897

Increase Median Width

Description: Increase median width

Prior Condition: Traversable median of unspecified width

Category: Roadside

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)
Value: 1.007
Adjusted Standard Error:
Unadjusted Standard Error: 0.004
Crash Reduction Factor (CRF)
Value: -0.7   (This value indicates an increase in crashes)
Adjusted Standard Error:
Unadjusted Standard Error: 0.4
Crash Type: Cross median,Fixed object,Run off road,Other
Crash Severity: K (fatal),A (serious injury),B (minor injury),C (possible injury)
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: 2001 to 2005
State: CA
Country: USA
Type of Methodology Used: 7
Sample Size (miles): 303 miles
Other Details
Included in Highway Safety Manual? No
Date Added to Clearinghouse: Nov-01-2015
Comments: This CMF applies to increasing median width by one foot for median-related crashes on four-lane freeways with traversable medians. Median-related crashes include rollover in the median, fixed object crashes other than median barrier, crash-involved vehicle comes to rest in the median, cross-median, or vehicle departs from and then returns to, the original traveled way.