CMF / CRF Details
Change speed limit
Countermeasure ID: 10584
Description: Change speed limit from X to Y
Prior Condition: No Prior Condition(s)
Category: Speed management
Study: Developing crash modification factors for roundabouts using a cross-sectional method, Al-Marafi et al., 2020
| Crash Modification Factor (CMF) |
|---|
| Value: |  |
| Adjusted Standard Error: | |
| Unadjusted Standard Error: | |
| Crash Reduction Factor (CRF) |
|---|
| Value: | |
| Adjusted Standard Error: | |
| Unadjusted Standard Error: | |
| Applicability |
|---|
| Crash Type: | All |
| Crash Severity: | K (fatal),A (serious injury),B (minor injury),C (possible injury) |
| Roadway Types: | Not specified |
| 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: | 40 |
| Maximum Speed Limit: | 70 |
| Speed Unit: | km/h |
| Speed Limit Comment: | |
| Area Type: | Urban |
| Traffic Volume: | |
| Average Traffic Volume: | |
| Time of Day: | |
| If countermeasure is intersection-based |
| Intersection Type: | Roadway/roadway (not interchange related) |
| Intersection Geometry: | Not specified |
| Traffic Control: | Roundabout |
| Major Road Traffic Volume: | Minimum of 1288 to Maximum of 16071 Annual Average Daily Traffic (AADT) |
| Minor Road Traffic Volume: | Minimum of 1200 to Maximum of 10002 Annual Average Daily Traffic (AADT) |
| Average Major Road Volume : | 6966 Annual Average Daily Traffic (AADT) |
| Average Minor Road Volume : | 4341 Annual Average Daily Traffic (AADT) |
| Development Details |
|---|
| Date Range of Data Used: | 2010 to 2015 |
| Municipality: | Toowoomba City |
| State: | notusa |
| Country: | Australia |
| Type of Methodology Used: | Regression cross-section |
| Sample Size (sites): | 49 sites |
| Other Details |
|---|
| Included in Highway Safety Manual? | No |
| Date Added to Clearinghouse: | Dec 17, 2020 |
| Comments: | CMFunction for speed limit (kph) on the major approach |
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