CMF / CRF Details

CMF ID: 8333

Install directional median openings at downstream U-turn locations


Prior Condition: Intersections with full median opening

Category: Alignment

Study: Safety Impacts of Directional Median Openings at Downstream U-Turn Locations, Qi et al., 2016

Star Quality Rating: 3 Stars   [View score details]
Crash Modification Factor (CMF)
Value: Equation
Adjusted Standard Error:
Unadjusted Standard Error:
Crash Reduction Factor (CRF)
Adjusted Standard Error:
Unadjusted Standard Error:
Crash Type: All
Crash Severity: All
Roadway Types: Principal Arterial Other Freeways and Expressways
Number of Lanes: 8
Road Division Type: Divided by Median
Speed Limit: 45
Area Type: Not specified
Traffic Volume: Minimum of 1200 to Maximum of 1600 Vehicles Per Hour
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: 2007 to 2011
Municipality: Houston
State: TX
Type of Methodology Used: Regression cross-section
Sample Size (crashes): 64 crashes
Sample Size (sites): 16 sites
Sample Size (site-years): 80 site-years
Other Details
Included in Highway Safety Manual? No
Date Added to Clearinghouse: Jan-17-2017
Comments: CMFs of placing a directional median open at location 1 in comparison to at location 2