CMF / CRF Details

CMF ID: 10489

Increase speed limit from 55 mph to 60 mph

Description:

Prior Condition:  Posted speed limit of 55 mph

Category: Speed management

Study: Speed Limit Change (55 mph to 60 mph) Safety Evaluation, Saleem et al., 2020

 
Star Quality Rating:4 Stars  [View score details]
Rating Points Total:110
Crash Modification Factor (CMF)
Value:0.654
Adjusted Standard Error:
Unadjusted Standard Error:0.335
Crash Reduction Factor (CRF)
Value:34.6  (This value indicates a decrease in crashes)
Adjusted Standard Error:
Unadjusted Standard Error:33.5
Applicability
Crash Type:All
Crash Severity:K (fatal),A (serious injury),B (minor injury)
Roadway Types:All
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:Undivided
Minimum Speed Limit:60
Maximum Speed Limit:60
Speed Unit:mph
Speed Limit Comment:
Area Type:Rural
Traffic Volume:
Average Traffic Volume:
Time of Day:All
If countermeasure is intersection-based
Intersection Type:Roadway/roadway (not interchange related)
Intersection Geometry:3-leg
Traffic Control:Stop-controlled
Major Road Traffic Volume:
Minor Road Traffic Volume:
Average Major Road Volume :
Average Minor Road Volume :
Development Details
Date Range of Data Used:2012 to 2018
Municipality:
State:MN
Country:
Type of Methodology Used:Before/after using empirical Bayes or full Bayes
Sample Size (crashes):4 crashes after
Sample Size (sites):64 sites before, 64 sites after
Other Details
Included in Highway Safety Manual?No
Date Added to Clearinghouse:Aug 14, 2020
Comments:This CMF is for 3-Leg Intersections (Thru-Stop Control) with Lighting.