CMF / CRF Details

CMF ID: 333

Change from permitted or permitted-protected to 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: 4 Stars   [View score details]
Rating Points Total: 120
Crash Modification Factor (CMF)
Value: 0.01
Adjusted Standard Error: 0.03
Unadjusted Standard Error: 0.01
Crash Reduction Factor (CRF)
Value: 99   (This value indicates a decrease in crashes)
Adjusted Standard Error: 3
Unadjusted Standard Error: 1
Applicability
Crash Type: Angle
Crash Severity: All
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.