CMF / CRF Details
CMF ID: 7979
Install a traffic signal and left turn lanes
Description:
Install a traffic signal and left turn lanes
Prior Condition: Intersections with a stop sign on minor roads
Category: Intersection traffic control
| Crash Modification Factor (CMF) |
|---|
| Value: | 0.424 |
| Adjusted Standard Error: | |
| Unadjusted Standard Error: | 0.028 |
| Crash Reduction Factor (CRF) |
|---|
| Value: | 57.6 (This value indicates a decrease in crashes) |
| Adjusted Standard Error: | |
| Unadjusted Standard Error: | 2.8 |
| Applicability |
|---|
| Crash Type: | Other |
| Crash Severity: | All |
| Roadway Types: | Not specified |
| Street Type: | |
| Minimum Number of Lanes: | 2 |
| Maximum Number of Lanes: | 2 |
| 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: | Not specified |
| Intersection Geometry: | 4-leg |
| Traffic Control: | Stop-controlled |
| Major Road Traffic Volume: | Minimum of 1360 to Maximum of 15500 Annual Average Daily Traffic (AADT) |
| Minor Road Traffic Volume: | Minimum of 1036 to Maximum of 8884 Annual Average Daily Traffic (AADT) |
| Average Major Road Volume : | 8555 Annual Average Daily Traffic (AADT) |
| Average Minor Road Volume : | 3997 Annual Average Daily Traffic (AADT) |
| Development Details |
|---|
| Date Range of Data Used: | 1992 to 2012 |
| Municipality: | |
| State: | NC |
| Country: | |
| Type of Methodology Used: | Before/after using empirical Bayes or full Bayes |
| Sample Size (crashes): | 762 crashes before, 310 crashes after |
| Sample Size (sites): | 48 sites before, 48 sites after |
| Sample Size (site-years): | 238 site-years before, 228 site-years after |
| Other Details |
|---|
| Included in Highway Safety Manual? | No |
| Date Added to Clearinghouse: | Nov 10, 2016 |
| Comments: | The CMF was developed for both rural and suburban areas. CMF applies to frontal impact crashes, including 1) left turn same roadway, 2) left turn different roadway, 3) angle, 4) right turn same roadway, 5) right turn different roadway, 6) sideswipe, and 7) head-on. |
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