CMF / CRF Details
Decrease median width from 64ft to 22ft
Countermeasure ID: 5513
Description: Decrease median width from 64ft to 22ft
Prior Condition: 64 ft wide median
Category: Access management
Study: Using multivariate adaptive regression splines (MARS) to develop crash modification factors for urban freeway interchange influence areas, Haleem et al., 2013
| Crash Modification Factor (CMF) |
|---|
| Value: | 3.227 |
| Adjusted Standard Error: | |
| Unadjusted Standard Error: | 0.329 |
| Crash Reduction Factor (CRF) |
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| Value: | -222.7 (This value indicates an increase in crashes) |
| Adjusted Standard Error: | |
| Unadjusted Standard Error: | 32.9 |
| Applicability |
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| 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: | 4 |
| Maximum Number of Lanes: | |
| Number of Lanes Direction: | |
| Number of Lanes Comment: | 4 - 6+ Lanes |
| Crash Weather: | Not specified |
| Road Division Type: | Divided by Median |
| Minimum Speed Limit: | |
| Maximum Speed Limit: | |
| Speed Unit: | |
| Speed Limit Comment: | |
| Area Type: | Urban |
| Traffic Volume: | Minimum of 5700 to Maximum of 309000 Annual Average Daily Traffic (AADT) |
| Average Traffic Volume: | 95338 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 |
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| Date Range of Data Used: | 2007 to 2010 |
| Municipality: | |
| State: | FL |
| Country: | USA |
| Type of Methodology Used: | Regression cross-section |
| Sample Size (crashes): | 18525 crashes |
| Other Details |
|---|
| Included in Highway Safety Manual? | No |
| Date Added to Clearinghouse: | Apr 30, 2014 |
| Comments: | CMF for urban freeway interchange areas |
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