CMF / CRF Details
CMF ID: 6063
Increase retroreflectivity of STOP signs
Description: Implementation of STOP signs with higher retroreflectivity
Prior Condition: Stop signs with low retroreflectivity
Category: Intersection traffic control
Study: Safety Evaluation of Increasing Retroreflectivity of STOP Signs, Persaud et al., 2007
Star Quality Rating: | [View score details] |
Rating Points Total: | 110 |
Crash Modification Factor (CMF) | |
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Value: | 0.956 |
Adjusted Standard Error: | |
Unadjusted Standard Error: | 0.06 |
Crash Reduction Factor (CRF) | |
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Value: | 4.4 (This value indicates a decrease in crashes) |
Adjusted Standard Error: | |
Unadjusted Standard Error: | 6 |
Applicability | |
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Crash Type: | All |
Crash Severity: | All |
Roadway Types: | All |
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: | |
Maximum Speed Limit: | |
Speed Unit: | |
Speed Limit Comment: | |
Area Type: | All |
Traffic Volume: | |
Average Traffic Volume: | |
Time of Day: | Night |
If countermeasure is intersection-based | |
Intersection Type: | |
Intersection Geometry: | 3-leg,4-leg |
Traffic Control: | Stop-controlled |
Major Road Traffic Volume: | Minimum of 344 to Maximum of 57,353 Annual Average Daily Traffic (AADT) |
Minor Road Traffic Volume: | Minimum of 71 to Maximum of 18,879 Annual Average Daily Traffic (AADT) |
Average Major Road Volume : | 8,783 Annual Average Daily Traffic (AADT) |
Average Minor Road Volume : | 2,127 Annual Average Daily Traffic (AADT) |
Development Details | |
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Date Range of Data Used: | 1995 to 2004 |
Municipality: | |
State: | CT,SC |
Country: | |
Type of Methodology Used: | Before/after using empirical Bayes or full Bayes |
Sample Size (crashes): | 937 crashes before, 619 crashes after |
Sample Size (sites): | 339 sites before, 339 sites after |
Sample Size (site-years): | 2056 site-years before, 1269 site-years after |
Other Details | |
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Included in Highway Safety Manual? | No |
Date Added to Clearinghouse: | Dec 08, 2014 |
Comments: | The CMF is not significant at the 95% confidence level |