CMF / CRF Details
CMF ID: 9400
Widen managed lane envelope
Description: The managed lane envelope is defined as the managed lane, the left shoulder, and the buffer between the lane and regular traffic. The width of the envelope is the combined width of these elements. This treatment is for widening this envelope.
Prior Condition: Managed lane with left shoulder and flush buffer with paint or pylons between managed lane and regular traffic.
Category: Roadway
Study: Safety Evaluation of Cross-Sectional Elements of Freeway Managed Lanes, Avelar and Fitzpatrick, 2018
| Star Quality Rating: |  [View score details] |
| Rating Points Total: | 90 |
| Crash Modification Factor (CMF) | |
|---|---|
| Value: | 0.956 |
| Adjusted Standard Error: | |
| Unadjusted Standard Error: | 0.013 |
| Crash Reduction Factor (CRF) | |
|---|---|
| Value: | 4.4 (This value indicates a decrease in crashes) |
| Adjusted Standard Error: | |
| Unadjusted Standard Error: | 1.3 |
| Applicability | |
|---|---|
| Crash Type: | Other |
| Crash Severity: | K (fatal),A (serious injury),B (minor injury),C (possible injury) |
| Roadway Types: | Not specified |
| Street Type: | |
| Minimum Number of Lanes: | 6 |
| Maximum Number of Lanes: | 10 |
| Number of Lanes Direction: | |
| Number of Lanes Comment: | |
| Crash Weather: | Not specified |
| Road Division Type: | Divided by Median |
| Minimum Speed Limit: | |
| Maximum Speed Limit: | |
| Speed Unit: | |
| Speed Limit Comment: | |
| Area Type: | Urban and suburban |
| Traffic Volume: | |
| 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: | 2007 to 2011 |
| Municipality: | Los Angeles |
| State: | CA |
| Country: | United States |
| Type of Methodology Used: | Regression cross-section |
| Sample Size (sites): | 8 sites |
| Sample Size (site-years): | 40 site-years |
| Sample Size (miles): | 128 miles |
| Sample Size (mile-years): | 640 mile-years |
