CMF / CRF Details
CMF ID: 9416
Four to five lane conversion
Description:
Prior Condition: Four-lane undivided urban roadway
Category: Roadway
Study: Safety Performance Evaluation of Urban Undivided Four-Lane to Five-Lane Conversion in Louisiana, Rahman et al., 2018
| Star Quality Rating: |  [View score details] |
| Rating Points Total: | 95 |
| Crash Modification Factor (CMF) | |
|---|---|
| Value: | 0.482 |
| Adjusted Standard Error: | |
| Unadjusted Standard Error: | 0.028 |
| Crash Reduction Factor (CRF) | |
|---|---|
| Value: | 51.8 (This value indicates a decrease in crashes) |
| Adjusted Standard Error: | |
| Unadjusted Standard Error: | 2.8 |
| Applicability | |
|---|---|
| Crash Type: | Non-intersection |
| Crash Severity: | All |
| Roadway Types: | Not specified |
| Street Type: | |
| Minimum Number of Lanes: | 4 |
| Maximum Number of Lanes: | 4 |
| 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: | Urban |
| Traffic Volume: | Minimum of 6800 to Maximum of 27304 Annual Average Daily Traffic (AADT) |
| Average Traffic Volume: | 19463 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: | 1996 to 2016 |
| Municipality: | |
| State: | LA |
| Country: | United States |
| Type of Methodology Used: | Before/after using empirical Bayes or full Bayes |
| Sample Size (crashes): | 490 crashes after |
| Sample Size (sites): | 9 sites before, 9 sites after |
| Sample Size (site-years): | 60 site-years before, 42 site-years after |
| Sample Size (miles): | 9.128 miles before, 9.128 miles after |
| Sample Size (miles): | 61.056 mile-years before, 42.370 mile-years after |
