CMF / CRF Details
CMF ID: 3340
Install variable speed limit signs
Description: Install variable speed limit signs
Prior Condition: No variable speed limit sign present
Category: Speed management
Study: Evaluation of Variable Speed Limits on I-270/I-255 in St. Louis, Bham et al., 2010
Star Quality Rating: |
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Crash Modification Factor (CMF) | |
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Value: | 0.92 |
Adjusted Standard Error: | |
Unadjusted Standard Error: |
Crash Reduction Factor (CRF) | |
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Value: | 8 (This value indicates a decrease in crashes) |
Adjusted Standard Error: | |
Unadjusted Standard Error: |
Applicability | |
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Crash Type: | All |
Crash Severity: | All |
Roadway Types: | Principal Arterial Interstate |
Number of Lanes: | |
Road Division Type: | |
Speed Limit: | 40 to 60 |
Area Type: | Urban |
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 | |
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Date Range of Data Used: | 2007 to 2009 |
Municipality: | St. Louis |
State: | MO |
Country: | U.S.A. |
Type of Methodology Used: | Before/after using empirical Bayes or full Bayes |
Sample Size (crashes): | 1636 crashes after |