CMF / CRF Details
CMF ID: 8076
Lower posted speed limit from 50 kph to 40 kph
Description:
Prior Condition: Speed limit of 50 km/hr
Category: Speed management
Study: Full Bayesian evaluation of the safety effects of reducing the posted speed limit in urban residential areas, Islam and El-Basyouny, 2015
| Star Quality Rating: |  [View score details] |
| Rating Points Total: | 135 |
| Crash Modification Factor (CMF) | |
|---|---|
| Value: | 0.74 |
| Adjusted Standard Error: | |
| Unadjusted Standard Error: | 0.03 |
| Crash Reduction Factor (CRF) | |
|---|---|
| Value: | 26 (This value indicates a decrease in crashes) |
| Adjusted Standard Error: | |
| Unadjusted Standard Error: | 3 |
| Applicability | |
|---|---|
| Crash Type: | All |
| Crash Severity: | All |
| Roadway Types: | Major Collector |
| 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: | 40 |
| Maximum Speed Limit: | 50 |
| Speed Unit: | km/h |
| Speed Limit Comment: | |
| Area Type: | Urban |
| Traffic Volume: | Minimum of 100 to Maximum of 11700 Annual Average Daily Traffic (AADT) |
| Average Traffic Volume: | |
| Time of Day: | |
| 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: | 2006 to 2013 |
| Municipality: | City of Edmonton |
| State: | notusa |
| Country: | Canada |
| Type of Methodology Used: | Before/after using empirical Bayes or full Bayes |
| Sample Size (crashes): | 107 crashes before, 85 crashes after |
| Sample Size (sites): | 27 sites before, 27 sites after |
| Other Details | |
|---|---|
| Included in Highway Safety Manual? | No |
| Date Added to Clearinghouse: | Nov 10, 2016 |
| Comments: | |
