CMF / CRF Details
CMF ID: 4084
Four to five lane conversion
Description:
Prior Condition: Four-lane undivided roadway
Category: Roadway
Study: Crash Modification Factor for an Inexpensive Yet Very Cost Effective Safety Improvement: Converting Undivided Four-Lane Urban Roadways to Five-Lane Roadways, Sun et al., 2012
| Star Quality Rating: |  [View score details] |
| Rating Points Total: | 40 |
| Crash Modification Factor (CMF) | |
|---|---|
| Value: | 0.45 |
| Adjusted Standard Error: | |
| Unadjusted Standard Error: | 0.051 |
| Crash Reduction Factor (CRF) | |
|---|---|
| Value: | 55 (This value indicates a decrease in crashes) |
| Adjusted Standard Error: | |
| Unadjusted Standard Error: | 5.1 |
| Applicability | |
|---|---|
| Crash Type: | All |
| 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: | |
| Average Traffic Volume: | 28000 Average Daily Traffic (ADT) |
| 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 2006 |
| Municipality: | Lafayette |
| State: | LA |
| Country: | USA |
| Type of Methodology Used: | Simple before/after |
| Sample Size (crashes): | 358 crashes before, 147 crashes after |
