CMF / CRF Details

CMF ID: 341

Change permitted to protected/permitted or permitted/protected

Description:

Prior Condition:  No Prior Condition(s)

Category: Intersection traffic control

Study: Accident Modification Factors for Traffic Engineering and ITS Improvements, Harkey et al., 2008

 
Star Quality Rating:3 Stars  [View score details]
Rating Points Total:100
Crash Modification Factor (CMF)
Value:0.98
Adjusted Standard Error:0.5
Unadjusted Standard Error:0.28
Crash Reduction Factor (CRF)
Value:2  (This value indicates a decrease in crashes)
Adjusted Standard Error:50
Unadjusted Standard Error:28
Applicability
Crash Type:Angle
Crash Severity:Not specified
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:Not specified
Traffic Control:Signalized
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:Before/after using empirical Bayes or full Bayes
Other Details
Included in Highway Safety Manual?No
Date Added to Clearinghouse:Dec 01, 2009
Comments:The number of crashes in the after period were not reported in this study, however, they have been recorded as 300 to give 10 points as a beneift of doubt for one or more of the following: (1) number of miles/sites in the reference/treatment group, (2) number of crashes in the references/treatment group, (3) reporting AADTs for the aggregate dataset but not for the disaggragate dataset used for CMF development.