CMF / CRF Details
CMF ID: 4030
Adjust All-Red Clearance Interval
Description:
The Fitch et al. procedure for calculating all-red clearance intervals takes into account intersection geometry and vehicle speeds. For further detail on this method, please refer to the paper.
Prior Condition: No Prior Condition(s)
Category: Intersection traffic control
| Crash Modification Factor (CMF) |
|---|
| Value: | 0.6 |
| Adjusted Standard Error: | |
| Unadjusted Standard Error: | |
| Crash Reduction Factor (CRF) |
|---|
| Value: | 40 (This value indicates a decrease in crashes) |
| Adjusted Standard Error: | |
| Unadjusted Standard Error: | |
| Applicability |
|---|
| Crash Type: | Angle,Head on,Sideswipe |
| Crash Severity: | K (fatal),A (serious injury),B (minor injury),C (possible injury) |
| Roadway Types: | Not Specified |
| Street Type: | |
| Minimum Number of Lanes: | |
| Maximum Number of Lanes: | |
| 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: | |
| Traffic Volume: | |
| Average Traffic Volume: | |
| Time of Day: | Not specified |
| If countermeasure is intersection-based |
| Intersection Type: | |
| Intersection Geometry: | |
| Traffic Control: | |
| Major Road Traffic Volume: | |
| Minor Road Traffic Volume: | |
| Average Major Road Volume : | |
| Average Minor Road Volume : | |
| Development Details |
|---|
| Date Range of Data Used: | |
| Municipality: | Sacramento County |
| State: | CA |
| Country: | |
| Type of Methodology Used: | Simple before/after |
| Sample Size (site-years): | 118 site-years before, 118 site-years after |
| Other Details |
|---|
| Included in Highway Safety Manual? | No |
| Date Added to Clearinghouse: | Jun 04, 2012 |
| Comments: | The number of crashes in the after period were not reported in this study, however, they have been recorded as 300 to give 10 points as a beneift of doubt for one or more of the following: (1) number of miles/sites in the reference/treatment group, (2) number of crashes in the references/treatment group, (3) reporting AADTs for the aggregate dataset but not for the disaggragate dataset used for CMF development. |
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