CMF / CRF Details

CMF ID: 9794

Conversion of intersection into single-lane roundabout

Description: Conversion of intersection into single-lane roundabout

Prior Condition: Traffic circle

Category: Intersection geometry

Study: Crash Modification Factors Based on Crash Histories of 148 Modern Roundabouts in Five States, Zhang and Wang, 2017

 
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Crash Modification Factor (CMF)
Value: 0.5
Adjusted Standard Error:
Unadjusted Standard Error: 0.72
Crash Reduction Factor (CRF)
Value: 50   (This value indicates a decrease in crashes)
Adjusted Standard Error:
Unadjusted Standard Error: 72
Applicability
Crash Type: All
Crash Severity: All
Roadway Types: Not specified
Number of Lanes:
Road Division Type:
Speed Limit:
Area Type: Not specified
Traffic Volume:
Average Traffic Volume:
Time of Day: Not specified
If countermeasure is intersection-based
Intersection Type:
Intersection Geometry: No values chosen.
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: 2005 to 2013
Municipality:
State: FL, IN, NY, PA, WA
Country: USA
Type of Methodology Used: Simple before/after
Sample Size (sites): 2 sites before, 2 sites after
Other Details
Included in Highway Safety Manual? No
Date Added to Clearinghouse: Oct-27-2018
Comments: Traffic circle to single lane roundabout