CMF / CRF Details

CMF ID: 117


Star Quality Rating:	[View score details]
Rating Points Total:	85

Crash Modification Factor (CMF)
Value:	0.79
Adjusted Standard Error:	0.18
Unadjusted Standard Error:	0.1

Crash Reduction Factor (CRF)
Value:	21 (This value indicates a decrease in crashes)
Adjusted Standard Error:	18
Unadjusted Standard Error:	10

Applicability
Crash Type:	Run off road,Single vehicle
Crash Severity:	All
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:	Rural
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:	Before/after using empirical Bayes or full Bayes

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 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.