CMF / CRF Details
CMF ID: 8342
Widen shoulder
Description:
Prior Condition: Freeway with narrower right shoulder
Category: Shoulder treatments
Study: Operational and Safety Trade-offs: Reducing Freeway Lane and Shoulder Width to Permit an Additional Lane, Dixon et al., 2016
| Star Quality Rating: |  [View score details] |
| Rating Points Total: | 80 |
| Crash Modification Factor (CMF) | |
|---|---|
| Value: | 0.91 |
| Adjusted Standard Error: | |
| Unadjusted Standard Error: | 0.046 |
| Crash Reduction Factor (CRF) | |
|---|---|
| Value: | 9 (This value indicates a decrease in crashes) |
| Adjusted Standard Error: | |
| Unadjusted Standard Error: | 4.6 |
| Applicability | |
|---|---|
| Crash Type: | All |
| Crash Severity: | All |
| Roadway Types: | Principal Arterial Other Freeways and Expressways |
| Street Type: | |
| Minimum Number of Lanes: | 2 |
| Maximum Number of Lanes: | 5 |
| Number of Lanes Direction: | |
| Number of Lanes Comment: | |
| Crash Weather: | Not specified |
| Road Division Type: | Divided by Median |
| Minimum Speed Limit: | 50 |
| Maximum Speed Limit: | |
| Speed Unit: | mph |
| Speed Limit Comment: | > = 50 mph |
| Area Type: | Urban |
| Traffic Volume: | Minimum of 200 to Maximum of 281450 Annual Average Daily Traffic (AADT) |
| Average Traffic Volume: | 152163 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: | 2010 to 2013 |
| Municipality: | Dallas, Houston, San Antonio |
| State: | TX |
| Country: | USA |
| Type of Methodology Used: | Regression cross-section |
| Sample Size (crashes): | 2202 crashes |
| Sample Size (sites): | 536 sites |
| Sample Size (site-years): | 2144 site-years |
| Other Details | |
|---|---|
| Included in Highway Safety Manual? | No |
| Date Added to Clearinghouse: | Jan 17, 2017 |
| Comments: | CMF applies to increasing right shoulder by 1 foot. |
