CMF / CRF Details

CMF ID: 7770


Star Quality Rating:	[View score details]
Rating Points Total:	60

Crash Modification Factor (CMF)
Value:	0.63
Adjusted Standard Error:
Unadjusted Standard Error:	0.15

Crash Reduction Factor (CRF)
Value:	37 (This value indicates a decrease in crashes)
Adjusted Standard Error:
Unadjusted Standard Error:	15

Applicability
Crash Type:	Run off road
Crash Severity:	K (fatal),A (serious injury),B (minor injury),C (possible injury)
Roadway Types:	All
Street Type:
Minimum Number of Lanes:	2
Maximum Number of Lanes:
Number of Lanes Direction:
Number of Lanes Comment:	> = 2 Lanes
Crash Weather:	Not specified
Road Division Type:	All
Minimum Speed Limit:	45
Maximum Speed Limit:	70
Speed Unit:	mph
Speed Limit Comment:
Area Type:	Rural
Traffic Volume:	Minimum of 2000 to Maximum of 50000 Annual Average Daily Traffic (AADT)
Average Traffic Volume:
Time of Day:	All
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:	2005 to 2010
Municipality:
State:	FL
Country:	USA
Type of Methodology Used:	Before/after using comparison group
Sample Size (sites):	30 sites before, 30 sites after
Sample Size (site-years):	60 site-years before, 60 site-years after
Sample Size (miles):	122 miles before, 122 miles after
Sample Size (miles):	244 mile-years before, 244 mile-years after

Other Details
Included in Highway Safety Manual?	No
Date Added to Clearinghouse:	Mar 08, 2016
Comments:	CMFs of installing shoulder rumble strips and widening shoulder width on rural multi-lane highways apply to single-vehicle run-off-road crashes 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.