CMF / CRF Details
CMF ID: 5646
Install edgeline pavement markings on narrow, rural, two-lane roads
Description: Install edgeline pavement markings on narrow (less than 22 ft.), rural, two-lane roads.
Prior Condition: No edge lines
Category: Delineation
Study: Investigating Safety Impact of Edge Line on Narrow Rural 2-lane Highways by Empirical Bayes Method, Sun et al., 2014
| Star Quality Rating: |  [View score details] |
| Rating Points Total: | 70 |
| Crash Modification Factor (CMF) | |
|---|---|
| Value: | 0.85 |
| Adjusted Standard Error: | |
| Unadjusted Standard Error: | 0.039 |
| Crash Reduction Factor (CRF) | |
|---|---|
| Value: | 15 (This value indicates a decrease in crashes) |
| Adjusted Standard Error: | |
| Unadjusted Standard Error: | 3.9 |
| Applicability | |
|---|---|
| Crash Type: | All |
| 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: | Undivided |
| Minimum Speed Limit: | |
| Maximum Speed Limit: | |
| Speed Unit: | |
| Speed Limit Comment: | |
| Area Type: | Rural |
| Traffic Volume: | |
| 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: | 2005 to 2011 |
| Municipality: | |
| State: | LA |
| Country: | United States |
| Type of Methodology Used: | Before/after using empirical Bayes or full Bayes |
| Sample Size (crashes): | 986 crashes before, 852 crashes after |
| Sample Size (sites): | 9 sites before, 9 sites after |
| Sample Size (site-years): | 27 site-years before, 27 site-years after |
| Sample Size (miles): | 109 miles before, 109 miles after |
| Sample Size (miles): | 329 mile-years before, 329 mile-years after |
| Other Details | |
|---|---|
| Included in Highway Safety Manual? | No |
| Date Added to Clearinghouse: | Aug 12, 2014 |
| Comments: | This CMF is for narrow 2-lane rural roads. |
