CMF / CRF Details
CMF ID: 4224
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: |  [View score details] |
| Rating Points Total: | 35 |
| Crash Modification Factor (CMF) | |
|---|---|
| Value: | 0.625 |
| Adjusted Standard Error: | |
| Unadjusted Standard Error: | |
| Crash Reduction Factor (CRF) | |
|---|---|
| Value: | 37.5 (This value indicates a decrease in crashes) |
| Adjusted Standard Error: | |
| Unadjusted Standard Error: | |
| Applicability | |
|---|---|
| Crash Type: | All |
| Crash Severity: | All |
| Roadway Types: | Principal Arterial Other |
| Street Type: | |
| Minimum Number of Lanes: | 1 |
| Maximum Number of Lanes: | 1 |
| Number of Lanes Direction: | |
| Number of Lanes Comment: | |
| Crash Weather: | Not specified |
| Road Division Type: | Undivided |
| Minimum Speed Limit: | |
| Maximum Speed Limit: | |
| Speed Unit: | |
| Speed Limit Comment: | |
| 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 |
