CMF / CRF Details
CMF ID: 4928
Conversion of no control/yield intersection into single- or multi-lane roundabout
Description: Conversion of no control/yield intersection into single- or multi-lane roundabout.
Prior Condition: The intersection was operating under no control or yield control.
Category: Intersection geometry
Study: Evaluation of Roundabout Safety, Qin et al., 2013
| Star Quality Rating: |  [View score details] |
| Rating Points Total: | 25 |
| Crash Modification Factor (CMF) | |
|---|---|
| Value: | 1.242 |
| Adjusted Standard Error: | |
| Unadjusted Standard Error: | 0.648 |
| Crash Reduction Factor (CRF) | |
|---|---|
| Value: | -24.18 (This value indicates an increase in crashes) |
| Adjusted Standard Error: | |
| Unadjusted Standard Error: | 64.8 |
| Applicability | |
|---|---|
| Crash Type: | All |
| Crash Severity: | All |
| 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 | |
|---|---|
| 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): | 7 crashes before, 9 crashes after |
