CMF / CRF Details
CMF ID: 5231
Convert traffic signals to unconventional median U-turns
Description: Remove existing traffic signals and replace with unconventional median U-turn
Prior Condition: Three and Four-Leg Signalized Intersections
Category: Intersection geometry
Study: Safety Effect of U-Turn Conversions in Tehran: Empirical Bayes Observational Before-And-After Study and Crash Prediction Models, Leila Azizi and Abdolreza Sheikholeslami, 2013
| Star Quality Rating: |  [View score details] |
| Rating Points Total: | 130 |
| Crash Modification Factor (CMF) | |
|---|---|
| Value: | 1.132 |
| Adjusted Standard Error: | |
| Unadjusted Standard Error: | 0.06 |
| Crash Reduction Factor (CRF) | |
|---|---|
| Value: | -13.2 (This value indicates an increase in crashes) |
| Adjusted Standard Error: | |
| Unadjusted Standard Error: | 6 |
| Applicability | |
|---|---|
| Crash Type: | All |
| Crash Severity: | All |
| Roadway Types: | Not specified |
| Street Type: | |
| Minimum Number of Lanes: | 3 |
| Maximum Number of Lanes: | |
| Number of Lanes Direction: | Both Directions |
| Number of Lanes Comment: | Multi Lane |
| Crash Weather: | Not specified |
| Road Division Type: | Divided by Median |
| Minimum Speed Limit: | |
| Maximum Speed Limit: | |
| Speed Unit: | |
| Speed Limit Comment: | |
| Area Type: | Urban |
| Traffic Volume: | |
| Average Traffic Volume: | |
| Time of Day: | Not specified |
| If countermeasure is intersection-based | |
| Intersection Type: | Roadway/roadway (not interchange related) |
| Intersection Geometry: | Not specified |
| Traffic Control: | Signalized |
| Major Road Traffic Volume: | Minimum of 33650 to Maximum of 70579 Average Daily Traffic (ADT) |
| Minor Road Traffic Volume: | Minimum of 9405 to Maximum of 31789 Average Daily Traffic (ADT) |
| Average Major Road Volume : | 46666 Average Daily Traffic (ADT) |
| Average Minor Road Volume : | 16757 Average Daily Traffic (ADT) |
| Development Details | |
|---|---|
| Date Range of Data Used: | 2001 to 2009 |
| Municipality: | |
| State: | notusa |
| Country: | Iran |
| Type of Methodology Used: | Before/after using empirical Bayes or full Bayes |
| Sample Size (crashes): | 286 crashes before, 556 crashes after |
| Other Details | |
|---|---|
| Included in Highway Safety Manual? | No |
| Date Added to Clearinghouse: | Dec 02, 2013 |
| Comments: | |
