CMF / CRF Details
CMF ID: 2841
Converting four-lane roadways to three-lane roadways with center turn lane (road diet)
Description:
Conversion of road segments from a four-lane to a three-lane cross-section with two-way left-turn lanes (also known as road diets).
Prior Condition: Four-lane undivided roadway
Category: Roadway
| Crash Modification Factor (CMF) |
|---|
| Value: | 0.53 |
| Adjusted Standard Error: | |
| Unadjusted Standard Error: | 0.02 |
| Crash Reduction Factor (CRF) |
|---|
| Value: | 47 (This value indicates a decrease in crashes) |
| Adjusted Standard Error: | |
| Unadjusted Standard Error: | 2 |
| Applicability |
|---|
| Crash Type: | All |
| Crash Severity: | All |
| Roadway Types: | Not Specified |
| Street Type: | |
| Minimum Number of Lanes: | 4 |
| Maximum Number of Lanes: | 4 |
| Number of Lanes Direction: | |
| Number of Lanes Comment: | |
| Crash Weather: | Not specified |
| Road Division Type: | Undivided |
| 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: | 1982 to 2004 |
| Municipality: | |
| State: | |
| Country: | |
| Type of Methodology Used: | Before/after using empirical Bayes or full Bayes |
| Other Details |
|---|
| Included in Highway Safety Manual? | No |
| Date Added to Clearinghouse: | Mar 21, 2011 |
| Comments: | When this CMF was initially entered in the Clearinghouse, it was incorrectly entered as a CMF of 0.47. In March 2015, this was corrected to be 0.53, as presented in the original paper. In February 2021, the area type for this CMF was changed from suburban to urban/suburban to account for the fact that the treatment sites were largely located in small urban areas. |
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