CMF / CRF Details
CMF ID: 8982
Install oversized chevron signs
Description:
Curve warning treatment with oversized chevron signs
Prior Condition: smaller 12x18in or 24x30in signs
Category: Signs
| Crash Modification Factor (CMF) |
|---|
| Value: | 0.56 |
| Adjusted Standard Error: | |
| Unadjusted Standard Error: | 0.184 |
| Crash Reduction Factor (CRF) |
|---|
| Value: | 44 (This value indicates a decrease in crashes) |
| Adjusted Standard Error: | |
| Unadjusted Standard Error: | 18.4 |
| Applicability |
|---|
| Crash Type: | Nighttime |
| Crash Severity: | All |
| 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: | Not specified |
| Traffic Volume: | Minimum of 173 to Maximum of 27235 Annual Average Daily Traffic (AADT) |
| Average Traffic Volume: | |
| Time of Day: | Night |
| 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: | |
| State: | IA,KS,MO |
| Country: | USA |
| Type of Methodology Used: | Before/after using empirical Bayes or full Bayes |
| Sample Size (sites): | 45 sites before, 45 sites after |
| Other Details |
|---|
| Included in Highway Safety Manual? | No |
| Date Added to Clearinghouse: | Nov 17, 2017 |
| Comments: | Presence of advisory speed signs 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. |
[View score details]