CMF / CRF Details
CMF ID: 9713
Raise posted speed
Description:
Prior Condition: No Prior Condition(s)
Category: Speed management
Study: Evaluating the Impact of Raising Speed Limit on Urban Freeways Using Mixed Effects Negative Binomial Regression, Kwayu et al., 2018
Star Quality Rating: | [View score details] |
Rating Points Total: | 115 |
Crash Modification Factor (CMF) | |
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Value: | 1.132 |
Adjusted Standard Error: | |
Unadjusted Standard Error: |
Crash Reduction Factor (CRF) | |
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Value: | -13.2 (This value indicates an increase in crashes) |
Adjusted Standard Error: | |
Unadjusted Standard Error: |
Applicability | |
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Crash Type: | Run off road |
Crash Severity: | All |
Roadway Types: | Principal Arterial Other Freeways and Expressways |
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: | Divided by Median |
Minimum Speed Limit: | 55 |
Maximum Speed Limit: | 70 |
Speed Unit: | mph |
Speed Limit Comment: | |
Area Type: | Urban |
Traffic Volume: | Minimum of 2694 to Maximum of 111047 Annual Average Daily Traffic (AADT) |
Average Traffic Volume: | 60326 Annual Average Daily Traffic (AADT) |
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 | |
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Date Range of Data Used: | 2000 to 2015 |
Municipality: | Detroit |
State: | MI |
Country: | USA |
Type of Methodology Used: | Regression cross-section |
Sample Size (crashes): | 20944 crashes |
Sample Size (site-years): | 3808 site-years |
Other Details | |
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Included in Highway Safety Manual? | No |
Date Added to Clearinghouse: | Oct 27, 2018 |
Comments: | Posted Speeds increased from 55mph to 65mph, 55mph to 70mph, and 65mph to 70mph |