CMF / CRF Details

CMF ID: 10024

Implement Active Traffic Management Strategies

Description: Implement a combination of Advisory Variable Speed Limits and Lane Use Control Signs on a section of interstate.

Prior Condition: Interstate segment with static speed limits and no lane use control signals.

Category: Advanced technology and ITS

Study: Evaluation of the Impact of the I-66 Active Traffic Management System: Phase II, Dutta et al., 2018

 
Star Quality Rating: 3 Stars   [View score details]
Crash Modification Factor (CMF)
Value: 1.127
Adjusted Standard Error:
Unadjusted Standard Error: 0.094
Crash Reduction Factor (CRF)
Value: -12.7   (This value indicates an increase in crashes)
Adjusted Standard Error:
Unadjusted Standard Error: 9.4
Applicability
Crash Type: Multiple vehicle
Crash Severity: All
Roadway Types: Principal Arterial Interstate
Number of Lanes: 6-8
Road Division Type: Divided by Median
Speed Limit:
Area Type: Suburban
Traffic Volume: Minimum of 167000 to Maximum of 184000 Annual Average Daily Traffic (AADT)
Average Traffic Volume: 176667 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: 2011 to 2016
Municipality:
State: VA
Country: United States
Type of Methodology Used: Before/after using empirical Bayes or full Bayes
Sample Size (crashes): 636 crashes before, 186 crashes after
Sample Size (sites): 3 sites before, 3 sites after
Sample Size (site-years): 12 site-years before, 3 site-years after
Sample Size (miles): 5.8 miles before, 5.8 miles after
Sample Size (miles): 23.2 mile-years before, 5.8 mile-years after
Other Details
Included in Highway Safety Manual? No
Date Added to Clearinghouse: Jul-26-2019
Comments: Applies to a segment with advisory variable speed limits and lane use control signals.