CMF / CRF Details
CMF ID: 8181
Reduce lane width from 10 ft to 9 ft
Description:
Prior Condition: 10-ft lane width
Category: Roadway
Study: Estimating the safety effects of lane widths on urban streets in Nebraska using the propensity scores-potential outcomes framework, Wood et al., 2015
| Star Quality Rating: |  [View score details] |
| Rating Points Total: | 115 |
| Crash Modification Factor (CMF) | |
|---|---|
| Value: | 0.52 |
| Adjusted Standard Error: | |
| Unadjusted Standard Error: | 0.147 |
| Crash Reduction Factor (CRF) | |
|---|---|
| Value: | 48 (This value indicates a decrease in crashes) |
| Adjusted Standard Error: | |
| Unadjusted Standard Error: | 14.7 |
| Applicability | |
|---|---|
| Crash Type: | Rear end |
| Crash Severity: | All |
| Roadway Types: | All |
| Street Type: | |
| Minimum Number of Lanes: | 2 |
| Maximum Number of Lanes: | 12 |
| Number of Lanes Direction: | |
| Number of Lanes Comment: | |
| Crash Weather: | Not specified |
| Road Division Type: | All |
| Minimum Speed Limit: | 25 |
| Maximum Speed Limit: | 50 |
| Speed Unit: | mph |
| Speed Limit Comment: | |
| Area Type: | Urban |
| Traffic Volume: | Minimum of 100 to Maximum of 19480 Annual Average Daily Traffic (AADT) |
| Average Traffic Volume: | 5348 Annual Average Daily Traffic (AADT) |
| Time of Day: | Not specified |
| 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: | 2003 to 2012 |
| Municipality: | |
| State: | NE |
| Country: | USA |
| Type of Methodology Used: | Regression cross-section |
| Sample Size (crashes): | 1958 crashes |
| Sample Size (sites): | 3050 sites |
| Sample Size (site-years): | 30500 site-years |
| Sample Size (miles): | 1180 miles |
| Other Details | |
|---|---|
| Included in Highway Safety Manual? | No |
| Date Added to Clearinghouse: | Nov 10, 2016 |
| Comments: | CMF for changing from 10ft to 9ft lane width. Applies to urban minor arterials and collectors. |
