CMF / CRF Details
CMF ID: 7009
Improve pavement friction (Chip Seal)
Description:
Chip seal treatment to improve pavement friction
Prior Condition: No Prior Condition(s)
Category: Roadway
| Crash Modification Factor (CMF) |
|---|
| Value: | 0.883 |
| Adjusted Standard Error: | |
| Unadjusted Standard Error: | 0.028 |
| Crash Reduction Factor (CRF) |
|---|
| Value: | |
| Adjusted Standard Error: | |
| Unadjusted Standard Error: | |
| Applicability |
|---|
| Crash Type: | Run off road |
| 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: | All |
| Minimum Speed Limit: | |
| Maximum Speed Limit: | |
| Speed Unit: | |
| Speed Limit Comment: | |
| Area Type: | All |
| Traffic Volume: | Minimum of 170 to Maximum of 24792 Annual Average Daily Traffic (AADT) |
| Average Traffic Volume: | 2751 Annual Average Daily Traffic (AADT) |
| 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: | 2000 to 2011 |
| Municipality: | |
| State: | CA,MN,NC,PA |
| Country: | USA |
| Type of Methodology Used: | Before/after using empirical Bayes or full Bayes |
| Sample Size (miles): | 2448 miles before, 2448 miles after |
| Other Details |
|---|
| Included in Highway Safety Manual? | No |
| Date Added to Clearinghouse: | Nov 01, 2015 |
| 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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