CMF / CRF Details

CMF ID: 9984

Convert a conventional signalized intersection to a signalized superstreet

Description: Convert a conventional signalized intersection to a signalized superstreet (also known as a restricted crossing U-turn intersection or a J-turn intersection)

Prior Condition: Conventional Signalized Intersection

Category: Intersection geometry

Study: Safety Evaluation of Signalized Restricted Crossing U-Turn Intersections, Hummer & Rao, 2017

 
Star Quality Rating: 4 Stars   [View score details]
Crash Modification Factor (CMF)
Value: 0.85
Adjusted Standard Error:
Unadjusted Standard Error: 0.16
Crash Reduction Factor (CRF)
Value: 15   (This value indicates a decrease in crashes)
Adjusted Standard Error:
Unadjusted Standard Error: 16
Applicability
Crash Type: All
Crash Severity: All
Roadway Types: Principal Arterial Other
Number of Lanes: 4-6
Road Division Type: Divided by Median
Speed Limit: 40-65 MPH
Area Type: Suburban
Traffic Volume:
Average Traffic Volume:
Time of Day: All
If countermeasure is intersection-based
Intersection Type: Roadway/roadway (not interchange related)
Intersection Geometry: 3-leg,4-leg
Traffic Control: Signalized
Major Road Traffic Volume:
Minor Road Traffic Volume:
Average Major Road Volume :
Average Minor Road Volume :
Development Details
Date Range of Data Used: 2002 to 2014
Municipality:
State: AL, NC, OH, TX
Country: United States
Type of Methodology Used: Before/after using comparison group
Sample Size (crashes): 1194 crashes before, 959 crashes after
Sample Size (sites): 11 sites before, 11 sites after
Sample Size (site-years): 39 site-years before, 26 site-years after
Other Details
Included in Highway Safety Manual? No
Date Added to Clearinghouse: Jul-26-2019
Comments: