CMF / CRF Details

CMF ID: 4225

Convert signalized intersection to modern roundabout

Description:

Prior Condition: Four-leg signalized intersection at interchange ramp terminal converted to a four-leg, one-lane, non-circular “eye drop” roundabout

Category: Intersection geometry

Study: Performance Evaluation of Roundabouts for Traffic Flow Improvements and Crash Reductions at a Highway Interchange in Oxford, MS, Uddin, Headrick, and Sullivan, 2012

 
Star Quality Rating: 3 Stars   [View score details]
Crash Modification Factor (CMF)
Value: 0.4
Adjusted Standard Error:
Unadjusted Standard Error:
Crash Reduction Factor (CRF)
Value: 60   (This value indicates a decrease in crashes)
Adjusted Standard Error:
Unadjusted Standard Error:
Applicability
Crash Type: All
Crash Severity: A (serious injury),B (minor injury),C (possible injury)
Roadway Types: Principal Arterial Other
Number of Lanes: 1
Road Division Type: Undivided
Speed Limit:
Area Type: Rural
Traffic Volume:
Average Traffic Volume:
Time of Day: Not specified
If countermeasure is intersection-based
Intersection Type: Roadway/roadway (interchange ramp terminal)
Intersection Geometry: 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: 2005 to 2009
Municipality: Oxford
State: MS
Country: United States
Type of Methodology Used: Before/after using empirical Bayes or full Bayes
Sample Size (site-years): 2.5 site-years before, 2.5 site-years after
Other Details
Included in Highway Safety Manual? No
Date Added to Clearinghouse: Nov-01-2012
Comments: Countermeasure name has been slightly modified for consistency across Clearinghouse