CMF / CRF Details

CMF ID: 447

Provide flashing beacons at stop controlled intersections

Description:

Prior Condition:  No Prior Condition(s)

Category: Intersection traffic control

Study: Safety Evaluation of Flashing Beacons at Stop Controlled Intersections, Srinivasan et al., 2008

 
Star Quality Rating:4 Stars  [View score details]
Rating Points Total:130
Crash Modification Factor (CMF)
Value:0.9
Adjusted Standard Error:0.06
Unadjusted Standard Error:0.05
Crash Reduction Factor (CRF)
Value:10  (This value indicates a decrease in crashes)
Adjusted Standard Error:6
Unadjusted Standard Error:5
Applicability
Crash Type:All
Crash Severity:A (serious injury),B (minor injury),C (possible injury)
Roadway Types:Not Specified
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:
Maximum Speed Limit:
Speed Unit:
Speed Limit Comment:
Area Type:All
Traffic Volume:
Average Traffic Volume:
Time of Day:
If countermeasure is intersection-based
Intersection Type:Roadway/roadway (not interchange related)
Intersection Geometry:4-leg
Traffic Control:Stop-controlled
Major Road Traffic Volume:Minimum of 250 to Maximum of 42520 Average Daily Traffic (ADT)
Minor Road Traffic Volume:Minimum of 90 to Maximum of 13270 Average Daily Traffic (ADT)
Average Major Road Volume :
Average Minor Road Volume :
Development Details
Date Range of Data Used:
Municipality:
State:
Country:
Type of Methodology Used:Before/after using empirical Bayes or full Bayes
Other Details
Included in Highway Safety Manual?Yes. HSM lists this CMF in bold font to indicate that it has the highest reliability since it has an adjusted standard error of 0.1 or less. However, it also includes an asterisk (*) to indicate that the CMF value itself is within the range 0.90 to 1.10, but that the confidence interval defined by the CMF ± two times the standard error may contain the value 1.0. This is important to note since a treatment with such an CMF could potentially result in (a) a reduction in crashes (safety benefit), (b) no change, or (c) an increase in crashes (safety disbenefit). HSM recommends that this CMF should be used with caution.
Date Added to Clearinghouse:Dec 01, 2009
Comments:Countermeasure name changed from "flashing beacons at four leg stop controlled intersections on two lane roads; standard and actuated beacons" to match HSM

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