CMF / CRF Details

CMF ID: 204

Convert four-leg intersection into two three-leg intersections

Description:

Prior Condition:  No Prior Condition(s)

Category: Intersection geometry

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

 
Star Quality Rating:3 Stars  [View score details]
Rating Points Total:75
Crash Modification Factor (CMF)
Value:1
Adjusted Standard Error:0.09
Unadjusted Standard Error:0.05
Crash Reduction Factor (CRF)
Value:0  (This value indicates a decrease in crashes)
Adjusted Standard Error:9
Unadjusted Standard Error:5
Applicability
Crash Type:All
Crash Severity:O (property damage only)
Roadway Types:Not Specified
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:Roadway/roadway (not interchange related)
Intersection Geometry:4-leg
Traffic Control:Not Specified
Major Road Traffic Volume:
Minor Road Traffic Volume:Minimum of 15% of total entering to Maximum of 30% of total entering Unit Unknown
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 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 to match HSM