CMF / CRF Details
CMF ID: 9421
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: | 90 |
| Crash Modification Factor (CMF) | |
|---|---|
| Value: | 0.426 |
| Adjusted Standard Error: | |
| Unadjusted Standard Error: | 0.071 |
| Crash Reduction Factor (CRF) | |
|---|---|
| Value: | 57.4 (This value indicates a decrease in crashes) |
| Adjusted Standard Error: | |
| Unadjusted Standard Error: | 7.1 |
| 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: | |
| Minimum Speed Limit: | |
| Maximum Speed Limit: | |
| Speed Unit: | |
| Speed Limit Comment: | |
| Area Type: | Urban and suburban |
| Traffic Volume: | Minimum of 24880 to Maximum of 27304 Annual Average Daily Traffic (AADT) |
| Average Traffic Volume: | 26092 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: | 2006 to 2016 |
| Municipality: | |
| State: | LA |
| Country: | United States |
| Type of Methodology Used: | Before/after using empirical Bayes or full Bayes |
| Sample Size (crashes): | 50 crashes after |
| Sample Size (sites): | 1 sites before, 1 sites after |
| Sample Size (site-years): | 7 site-years before, 3 site-years after |
| Sample Size (miles): | 0.8 miles before, 0.8 miles after |
| Sample Size (miles): | 5.6 mile-years before, 2.4 mile-years after |
| Other Details | |
|---|---|
| Included in Highway Safety Manual? | No |
| Date Added to Clearinghouse: | Oct 27, 2018 |
| Comments: | This CMF applies in areas with a population between 200,000 and 500,000 people. |
