CMF / CRF Details

CMF ID: 8007


Star Quality Rating:	[View score details]
Rating Points Total:	95

Crash Modification Factor (CMF)
Value:	0.916
Adjusted Standard Error:
Unadjusted Standard Error:	0.101

Crash Reduction Factor (CRF)
Value:	8.4 (This value indicates a decrease in crashes)
Adjusted Standard Error:
Unadjusted Standard Error:	10.1

Applicability
Crash Type:	Other
Crash Severity:	All
Roadway Types:	Not specified
Street Type:
Minimum Number of Lanes:	2
Maximum Number of Lanes:	2
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:	All
Traffic Volume:
Average Traffic Volume:
Time of Day:	All
If countermeasure is intersection-based
Intersection Type:	Not specified
Intersection Geometry:	3-leg,4-leg
Traffic Control:	Signalized
Major Road Traffic Volume:	Minimum of 1360 to Maximum of 18248 Annual Average Daily Traffic (AADT)
Minor Road Traffic Volume:	Minimum of 746 to Maximum of 13880 Annual Average Daily Traffic (AADT)
Average Major Road Volume :	8323 Annual Average Daily Traffic (AADT)
Average Minor Road Volume :	4188 Annual Average Daily Traffic (AADT)

Development Details
Date Range of Data Used:	1992 to 2012
Municipality:
State:	NC
Country:
Type of Methodology Used:	Before/after using empirical Bayes or full Bayes
Sample Size (crashes):	1483 crashes before, 564 crashes after
Sample Size (sites):	117 sites before, 117 sites after
Sample Size (site-years):	576 site-years before, 559 site-years after

Other Details
Included in Highway Safety Manual?	No
Date Added to Clearinghouse:	Nov 10, 2016
Comments:	The CMF was developed for both rural and suburban areas. CMF applies to frontal impact crashes, including 1) left turn same roadway, 2) left turn different roadway, and 3) angle. 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.