CMF / CRF Details

CMF ID: 7774


Star Quality Rating:	[View score details]
Rating Points Total:	120

Crash Modification Factor (CMF)
Value:	0.63
Adjusted Standard Error:
Unadjusted Standard Error:	0.12

Crash Reduction Factor (CRF)
Value:	37 (This value indicates a decrease in crashes)
Adjusted Standard Error:
Unadjusted Standard Error:	12

Applicability
Crash Type:	All
Crash Severity:	K (fatal),A (serious injury),B (minor injury),C (possible injury)
Roadway Types:	All
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:	All
Minimum Speed Limit:
Maximum Speed Limit:
Speed Unit:
Speed Limit Comment:
Area Type:	All
Traffic Volume:
Average Traffic Volume:
Time of Day:	Night
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:	2006 to 2010
Municipality:
State:	FL
Country:	USA
Type of Methodology Used:	Before/after using empirical Bayes or full Bayes
Sample Size (sites):	45 sites before, 45 sites after
Sample Size (site-years):	135 site-years before, 90 site-years after
Sample Size (miles):	131.7 miles before, 131.7 miles after
Sample Size (miles):	395 mile-years before, 263 mile-years after

Other Details
Included in Highway Safety Manual?	No
Date Added to Clearinghouse:	Mar 08, 2016
Comments:	CMFs of adding lighting on all roads types with all number of lanes. 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.