CMF / CRF Details

CMF ID: 9403

Convert intersection with minor-road stop control to modern roundabout


Prior Condition: Intersection with stop-control on the minor roadway.

Category: Intersection geometry

Study: Safety of Roundabout: The Details Matter, Sun et al., 2018

Star Quality Rating: 3 Stars   [View score details]
Rating Points Total: 95
Crash Modification Factor (CMF)
Value: 0.28
Adjusted Standard Error:
Unadjusted Standard Error: 0.054
Crash Reduction Factor (CRF)
Value: 72   (This value indicates a decrease in crashes)
Adjusted Standard Error:
Unadjusted Standard Error: 5.4
Crash Type: All
Crash Severity: All
Roadway Types: Not specified
Street Type:
Minimum Number of Lanes:
Maximum Number of Lanes:
Number of Lanes Direction:
Number of Lanes Comment:
Crash Weather: Not specified
Road Division Type:
Minimum Speed Limit:
Maximum Speed Limit:
Speed Unit:
Speed Limit Comment:
Area Type: Urban and suburban
Traffic Volume:
Average Traffic Volume:
Time of Day: All
If countermeasure is intersection-based
Intersection Type:
Intersection Geometry: 3-leg,4-leg
Traffic Control: Stop-controlled
Major Road Traffic Volume:
Minor Road Traffic Volume:
Average Major Road Volume :
Average Minor Road Volume :
Development Details
Date Range of Data Used:
State: LA
Country: United States
Type of Methodology Used: Before/after using empirical Bayes or full Bayes
Sample Size (crashes): 124 crashes before, 37 crashes after
Sample Size (sites): 5 sites before, 5 sites after
Other Details
Included in Highway Safety Manual? No
Date Added to Clearinghouse: Oct-27-2018
Comments: This CMF is for converting 3- or 4-leg minor stop control intersections to roundabout.