CMF / CRF Details
CMF ID: 5228
Conversion of intersection into low-speed roundabout
Description: Conversion of intersection into low-speed roundabout
Prior Condition: The intersection was operating under no control, yield, TWSC, AWSC, or signal control.
Category: Intersection geometry
Study: Evaluation of Roundabout Safety, Qin et al., 2013
Star Quality Rating: | [View score details] |
Rating Points Total: | 50 |
Crash Modification Factor (CMF) | |
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Value: | 0.473 |
Adjusted Standard Error: | |
Unadjusted Standard Error: | 0.113 |
Crash Reduction Factor (CRF) | |
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Value: | 52.73 (This value indicates a decrease in crashes) |
Adjusted Standard Error: | |
Unadjusted Standard Error: | 11.3 |
Applicability | |
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Crash Type: | All |
Crash Severity: | K (fatal),A (serious injury),B (minor injury),C (possible injury) |
Roadway Types: | Not specified |
Street Type: | |
Minimum Number of Lanes: | 2 |
Maximum Number of Lanes: | 4 |
Number of Lanes Direction: | |
Number of Lanes Comment: | |
Crash Weather: | Not specified |
Road Division Type: | All |
Minimum Speed Limit: | |
Maximum Speed Limit: | |
Speed Unit: | |
Speed Limit Comment: | |
Area Type: | All |
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: | Other |
Major Road Traffic Volume: | Minimum of 4100 (total entering) to Maximum of 48100 (total entering) Annual Average Daily Traffic (AADT) |
Minor Road Traffic Volume: | |
Average Major Road Volume : | |
Average Minor Road Volume : |
Development Details | |
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Date Range of Data Used: | 1994 to 2010 |
Municipality: | Statewide |
State: | WI |
Country: | USA |
Type of Methodology Used: | Before/after using empirical Bayes or full Bayes |
Sample Size (crashes): | 55 crashes before, 26 crashes after |