CMF / CRF Details
CMF ID: 4395
Install safety edge treatment
Description:
The safety edge is a low-cost treatment that is implemented in conjunction with pavement resurfacing and is intended to help minimize drop-off-related crashes.
Prior Condition: Rural highways prior to resurfacing and installation of safety edge treatment
Category: Shoulder treatments
| Crash Modification Factor (CMF) |
|---|
| Value: | 0.615 |
| Adjusted Standard Error: | |
| Unadjusted Standard Error: | 0.287 |
| Crash Reduction Factor (CRF) |
|---|
| Value: | 38.503 (This value indicates a decrease in crashes) |
| Adjusted Standard Error: | |
| Unadjusted Standard Error: | 28.727 |
| Applicability |
|---|
| Crash Type: | Other |
| Crash Severity: | K (fatal),A (serious injury),B (minor injury),C (possible injury) |
| Roadway Types: | Principal Arterial Other |
| 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: | Rural |
| Traffic Volume: | Minimum of 376 to Maximum of 13615 Annual Average Daily Traffic (AADT) |
| Average Traffic Volume: | |
| Time of Day: | All |
| 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: | 1999 to 2008 |
| Municipality: | |
| State: | IN |
| Country: | |
| Type of Methodology Used: | Before/after using empirical Bayes or full Bayes |
| Sample Size (miles): | 366 miles before, 366 miles after |
| Other Details |
|---|
| Included in Highway Safety Manual? | No |
| Date Added to Clearinghouse: | Dec 06, 2012 |
| Comments: | For drop-off-related crashesUnpaved shoulder study sites 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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