CMF / CRF Details

CMF ID: 9591

Increase speed limit from 65 mph to 70 mph

Description:

Prior Condition:  Interstate system with 65 MPH

Category: Speed management

Study: Safety Evaluation of Change in Posted Speed Limit From 65 MPH to 70 MPH on Rural Virginia Interstate System, , 2018

 
Star Quality Rating:4 Stars  [View score details]
Rating Points Total:120
Crash Modification Factor (CMF)
Value:0.997
Adjusted Standard Error:
Unadjusted Standard Error:0.021
Crash Reduction Factor (CRF)
Value:0.3  (This value indicates a decrease in crashes)
Adjusted Standard Error:
Unadjusted Standard Error:2.1
Applicability
Crash Type:All
Crash Severity:All
Roadway Types:Principal Arterial Interstate
Street Type:
Minimum Number of Lanes:2
Maximum Number of Lanes:4
Number of Lanes Direction:
Number of Lanes Comment:
Crash Weather:Not specified
Road Division Type:
Minimum Speed Limit:65
Maximum Speed Limit:65
Speed Unit:mph
Speed Limit Comment:
Area Type:Rural
Traffic Volume:Minimum of 3279 to Maximum of 58887 Annual Average Daily Traffic (AADT)
Average Traffic Volume:19565 Annual Average Daily Traffic (AADT)
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:2006 to 2014
Municipality:
State:VA
Country:
Type of Methodology Used:Before/after using empirical Bayes or full Bayes
Sample Size (crashes):3763 crashes after
Sample Size (sites):776 sites before, 776 sites after
Sample Size (site-years):3104 site-years before, 3104 site-years after
Sample Size (miles):1076 miles before, 1076 miles after
Sample Size (miles):4304 mile-years before, 4304 mile-years after
Other Details
Included in Highway Safety Manual?No
Date Added to Clearinghouse:Oct 27, 2018
Comments:CMF for crashes at base freeway segments.