CMF / CRF Details
Increase lane width from 11 feet to 12 feet
Countermeasure ID: 8337
Description:
Prior Condition: Freeway with 11 ft lane
Category: Roadway
Study: Operational and Safety Trade-offs: Reducing Freeway Lane and Shoulder Width to Permit an Additional Lane, Dixon et al., 2016
| Crash Modification Factor (CMF) |
|---|
| Value: | 0.88 |
| Adjusted Standard Error: | |
| Unadjusted Standard Error: | 0.048 |
| Crash Reduction Factor (CRF) |
|---|
| Value: | 12 (This value indicates a decrease in crashes) |
| Adjusted Standard Error: | |
| Unadjusted Standard Error: | 4.8 |
| Applicability |
|---|
| Crash Type: | All |
| Crash Severity: | K (fatal),A (serious injury),B (minor injury),C (possible injury) |
| Roadway Types: | Principal Arterial Other Freeways and Expressways |
| Street Type: | |
| Minimum Number of Lanes: | 5 |
| Maximum Number of Lanes: | 5 |
| Number of Lanes Direction: | One 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 Average Daily Traffic (ADT) |
| Average Traffic Volume: | 152163 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: | 2010 to 2013 |
| Municipality: | Dallas, Houston, San Antonia |
| State: | TX |
| Country: | USA |
| Type of Methodology Used: | Regression cross-section |
| Sample Size (crashes): | 407 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: | |
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