CMF / CRF Details
CMF ID: 2464
Closely spaced single-lane entrance and exit ramp vs. single-lane entrance and exit ramps with continuous auxiliary lane
Description: Arrangement has one-line entrance ramp closely followed by one-lane exit.
Prior Condition: No Prior Condition(s)
Category: Interchange design
Study: Evaluation of the Safety Effects of Lane Arrangements on Freeway Segments with Closely Spaced Entrance and Exit Ramps, Liu et al., 2010
| Star Quality Rating: |  [View score details] |
| Rating Points Total: | 100 |
| Crash Modification Factor (CMF) | |
|---|---|
| Value: | 1.46 |
| Adjusted Standard Error: | |
| Unadjusted Standard Error: | 0.31 |
| Crash Reduction Factor (CRF) | |
|---|---|
| Value: | -46.1 (This value indicates an increase in crashes) |
| Adjusted Standard Error: | |
| Unadjusted Standard Error: | 31.2 |
| 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: | 55 |
| Maximum Speed Limit: | 70 |
| Speed Unit: | mph |
| Speed Limit Comment: | |
| Area Type: | |
| Traffic Volume: | Minimum of 28500 to Maximum of 282000 Average Daily Traffic (ADT) |
| Average Traffic Volume: | |
| 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: | 2004 to 2006 |
| Municipality: | |
| State: | FL |
| Country: | |
| Type of Methodology Used: | Regression cross-section |
| Other Details | |
|---|---|
| Included in Highway Safety Manual? | No |
| Date Added to Clearinghouse: | Aug 11, 2010 |
| Comments: | |
