CMF / CRF Details
Conversion of intersection to roundabout
Countermeasure ID: 4868
Description: Conversion of stop- and signal-controlled intersections into roundabouts
Prior Condition: Stop- or signal-controlled intersection
Category: Intersection geometry
Study: Evaluating the Performance and Safety Effectiveness of Roundabouts, , 2011
| Star Quality Rating: |  [View score details] |
| Rating Points Total: | 130 |
| Crash Modification Factor (CMF) | |
|---|---|
| Value: | 0.583 |
| Adjusted Standard Error: | |
| Unadjusted Standard Error: | 0.074 |
| Crash Reduction Factor (CRF) | |
|---|---|
| Value: | 41.7 (This value indicates a decrease in crashes) |
| Adjusted Standard Error: | |
| Unadjusted Standard Error: | 7.4 |
| Applicability | |
|---|---|
| Crash Type: | All |
| Crash Severity: | A (serious injury),B (minor injury),C (possible injury) |
| Roadway Types: | All |
| 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: | All |
| Traffic Volume: | |
| Average Traffic Volume: | |
| Time of Day: | All |
| If countermeasure is intersection-based | |
| Intersection Type: | |
| Intersection Geometry: | Not specified |
| Traffic Control: | Roundabout |
| Major Road Traffic Volume: | Minimum of 1000 to Maximum of 26366 Annual Average Daily Traffic (AADT) |
| Minor Road Traffic Volume: | Minimum of 500 to Maximum of 13750 Annual Average Daily Traffic (AADT) |
| Average Major Road Volume : | 11181 Annual Average Daily Traffic (AADT) |
| Average Minor Road Volume : | 5600 Annual Average Daily Traffic (AADT) |
| Development Details | |
|---|---|
| Date Range of Data Used: | 2001 to 2010 |
| Municipality: | |
| State: | MI |
| Country: | |
| Type of Methodology Used: | Before/after using empirical Bayes or full Bayes |
| Sample Size (crashes): | 80 crashes after |
| Other Details | |
|---|---|
| Included in Highway Safety Manual? | No |
| Date Added to Clearinghouse: | May 01, 2013 |
| Comments: | This CMF includes effects from triple lane roundabouts. |
