CMF / CRF Details
Convert a conventional signalized intersection to a signalized superstreet
Countermeasure ID: 9985
Description: Convert a conventional signalized intersection to a signalized superstreet (also known as a restricted crossing U-turn intersection or a J-turn intersection)
Prior Condition: Conventional Signalized Intersection
Category: Intersection geometry
Study: Safety Evaluation of Signalized Restricted Crossing U-Turn Intersections, Hummer & Rao, 2017
| Star Quality Rating: |  [View score details] |
| Rating Points Total: | 90 |
| Crash Modification Factor (CMF) | |
|---|---|
| Value: | 0.78 |
| Adjusted Standard Error: | |
| Unadjusted Standard Error: | 0.2 |
| Crash Reduction Factor (CRF) | |
|---|---|
| Value: | 22 (This value indicates a decrease in crashes) |
| Adjusted Standard Error: | |
| Unadjusted Standard Error: | 20 |
| Applicability | |
|---|---|
| Crash Type: | All |
| Crash Severity: | K (fatal),A (serious injury),B (minor injury),C (possible injury) |
| Roadway Types: | Principal Arterial Other |
| Street Type: | |
| Minimum Number of Lanes: | 4 |
| Maximum Number of Lanes: | 6 |
| Number of Lanes Direction: | |
| Number of Lanes Comment: | |
| Crash Weather: | Not specified |
| Road Division Type: | Divided by Median |
| Minimum Speed Limit: | 40 |
| Maximum Speed Limit: | 65 |
| Speed Unit: | mph |
| Speed Limit Comment: | |
| Area Type: | Suburban |
| 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: | |
| Minor Road Traffic Volume: | |
| Average Major Road Volume : | |
| Average Minor Road Volume : | |
| Development Details | |
|---|---|
| Date Range of Data Used: | 2002 to 2014 |
| Municipality: | |
| State: | AL,NC,OH,TX |
| Country: | United States |
| Type of Methodology Used: | Before/after using comparison group |
| Sample Size (crashes): | 413 crashes before, 315 crashes after |
| Sample Size (sites): | 11 sites before, 11 sites after |
| Sample Size (site-years): | 39 site-years before, 26 site-years after |
| Other Details | |
|---|---|
| Included in Highway Safety Manual? | No |
| Date Added to Clearinghouse: | Jul 26, 2019 |
| Comments: | |
