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:3 Stars  [View score details]
Rating Points Total:90
Crash Modification Factor (CMF)
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
Crash Type:All
Crash Severity:All
Roadway Types:Principal Arterial Other
Street Type:
Minimum Number of Lanes:4
Maximum Number of Lanes:6
Number of Lanes Direction:
Number of Lanes Comment:
Crash Weather:Not specified
Road Division Type:Divided by Median
Minimum Speed Limit:40
Maximum Speed Limit:65
Speed Unit:mph
Speed Limit Comment:
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
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