CMF / CRF Details
CMF ID: 249
Provide a channelized left-turn lane on both major- and minor-road approaches
Description:
Provide a channelized left-turn lane on both major- and minor-road approaches
Prior Condition: No Prior Condition(s)
Category: Intersection geometry
| Crash Modification Factor (CMF) |
|---|
| Value: | 0.73 |
| Adjusted Standard Error: | 0.23 |
| Unadjusted Standard Error: | 0.13 |
| Crash Reduction Factor (CRF) |
|---|
| Value: | 27 (This value indicates a decrease in crashes) |
| Adjusted Standard Error: | 23 |
| Unadjusted Standard Error: | 13 |
| Applicability |
|---|
| Crash Type: | All |
| Crash Severity: | A (serious injury),B (minor injury),C (possible injury) |
| Roadway Types: | Not Specified |
| Street Type: | |
| Minimum Number of Lanes: | 2 |
| Maximum Number of Lanes: | 2 |
| 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: | Rural |
| Traffic Volume: | |
| Average Traffic Volume: | |
| Time of Day: | |
| If countermeasure is intersection-based |
| Intersection Type: | Roadway/roadway (not interchange related) |
| Intersection Geometry: | 3-leg |
| Traffic Control: | Not Specified |
| Major Road Traffic Volume: | Minimum of 5000 to Maximum of 15000 Average Daily Traffic (ADT) |
| Minor Road Traffic Volume: | |
| Average Major Road Volume : | |
| Average Minor Road Volume : | |
| Development Details |
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| Date Range of Data Used: | |
| Municipality: | |
| State: | |
| Country: | |
| Type of Methodology Used: | Meta-analysis |
| Other Details |
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| Included in Highway Safety Manual? | Yes. HSM lists this CMF in italics font to indicate that it has a lower reliability than bold font CMFs since it has an adjusted standard error of 0.2 to 0.3. |
| Date Added to Clearinghouse: | Dec 01, 2009 |
| Comments: | Countermeasure name changed from "physical channelization of left-turn lane on major road" to match HSM. |
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