CMF / CRF Details

CMF ID: 77

Install changeable "Queue Ahead" warning signs

Description:

Prior Condition:  No Prior Condition(s)

Category: Advanced technology and ITS

Study: Handbook of Road Safety Measures, Elvik, R. and Vaa, T., 2004

 
Star Quality Rating:3 Stars  [View score details]
Rating Points Total:105
Crash Modification Factor (CMF)
Value:1.16
Adjusted Standard Error:
Unadjusted Standard Error:0.08
Crash Reduction Factor (CRF)
Value:-16  (This value indicates an increase in crashes)
Adjusted Standard Error:
Unadjusted Standard Error:8
Applicability
Crash Type:Rear end
Crash Severity:O (property damage only)
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:
Minimum Speed Limit:
Maximum Speed Limit:
Speed Unit:
Speed Limit Comment:
Area Type:Urban
Traffic Volume:
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:
Municipality:
State:
Country:
Type of Methodology Used:Meta-analysis
Other Details
Included in Highway Safety Manual?Yes. HSM lists this CMF in italics font to indicate that it has a lower reliability than bold font CMFs since it has an adjusted standard error of 0.2 to 0.3.
Date Added to Clearinghouse:Dec 01, 2009
Comments:Countermeasure name changed to match HSM