CMF / CRF Details
CMF ID: 4681
Change length of deceleration lane from 401-500 ft. to 601-700 ft.
Description: Increase the length of an existing deceleration lane from 401-500 ft. long to 601-700 ft. long.
Prior Condition: Deceleration lane length between 401-500 ft.
Category: Interchange design
Study: Selecting Optimal Deceleration Lane Lengths at Freeway Diverge Areas Combining Safety and Operational Effects, Chen, Zhou, and Lin, 2012
| Star Quality Rating: |  [View score details] |
| Rating Points Total: | 55 |
| Crash Modification Factor (CMF) | |
|---|---|
| Value: | 0.59 |
| Adjusted Standard Error: | |
| Unadjusted Standard Error: | 0.194 |
| Crash Reduction Factor (CRF) | |
|---|---|
| Value: | 40.97 (This value indicates a decrease in crashes) |
| Adjusted Standard Error: | |
| Unadjusted Standard Error: | 19.4 |
| Applicability | |
|---|---|
| Crash Type: | All |
| Crash Severity: | All |
| Roadway Types: | Principal Arterial Other Freeways and Expressways |
| Street Type: | |
| Minimum Number of Lanes: | |
| Maximum Number of Lanes: | |
| Number of Lanes Direction: | |
| Number of Lanes Comment: | |
| Crash Weather: | Not specified |
| Road Division Type: | |
| Minimum Speed Limit: | |
| Maximum Speed Limit: | |
| Speed Unit: | |
| Speed Limit Comment: | |
| Area Type: | Not specified |
| Traffic Volume: | |
| Average Traffic Volume: | |
| 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: | 2004 to 2006 |
| Municipality: | |
| State: | FL |
| Country: | USA |
| Type of Methodology Used: | Non-regression cross-section |
| Sample Size (crashes): | 55 crashes |
| Other Details | |
|---|---|
| Included in Highway Safety Manual? | No |
| Date Added to Clearinghouse: | May 01, 2013 |
| Comments: | |
