CMF / CRF Details
Conversion of signalized intersection into single- or multi-lane roundabout
Countermeasure ID: 5523
Description:
Prior Condition: Signalized intersection
Category: Intersection geometry
Study: Evidence of Mixed Safety Performance among Roundabouts Converted from Signalized Intersections, Russo et al., 2014
| Crash Modification Factor (CMF) |
|---|
| Value: | 1.92 |
| Adjusted Standard Error: | |
| Unadjusted Standard Error: | 0.07 |
| Crash Reduction Factor (CRF) |
|---|
| Value: | -92 (This value indicates an increase in crashes) |
| Adjusted Standard Error: | |
| Unadjusted Standard Error: | 7 |
| Applicability |
|---|
| Crash Type: | All |
| Crash Severity: | All |
| Roadway Types: | Not specified |
| Street Type: | |
| Minimum Number of Lanes: | 1 |
| Maximum Number of Lanes: | 3 |
| 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: | Not specified |
| 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: | Signalized |
| Major Road Traffic Volume: | Minimum of 5700 to Maximum of 32900 Annual Average Daily Traffic (AADT) |
| Minor Road Traffic Volume: | Minimum of 1900 to Maximum of 24200 Annual Average Daily Traffic (AADT) |
| Average Major Road Volume : | 17700 Annual Average Daily Traffic (AADT) |
| Average Minor Road Volume : | 7900 Annual Average Daily Traffic (AADT) |
| Development Details |
|---|
| Date Range of Data Used: | 2000 to 2012 |
| Municipality: | |
| State: | MI |
| Country: | USA |
| Type of Methodology Used: | Before/after using empirical Bayes or full Bayes |
| Sample Size (crashes): | 743 crashes before, 1875 crashes after |
| Sample Size (sites): | 22 sites before, 22 sites after |
| Sample Size (site-years): | 66 site-years before, 89 site-years after |
| Other Details |
|---|
| Included in Highway Safety Manual? | No |
| Date Added to Clearinghouse: | Aug 12, 2014 |
| Comments: | |
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