CMF / CRF Details

CMF ID: 8476

Install an intersection conflict warning system (ICWS) with a combination of overhead and advanced post mounted signs (various messages) and flashers

Description: Install an intersection conflict warning system (ICWS) with a combination of overhead and advanced post mounted signs (various messages) and flashers

Prior Condition: No intersection conflict warning systems

Category: Signs

Study: Multi-State Safety Evaluation of Intersection Conflict Warning Systems (ICWS), Himes et al, 2016

 
Star Quality Rating: 4 Stars   [View score details]
Crash Modification Factor (CMF)
Value: 0.697
Adjusted Standard Error:
Unadjusted Standard Error: 0.113
Crash Reduction Factor (CRF)
Value: 30.3   (This value indicates a decrease in crashes)
Adjusted Standard Error:
Unadjusted Standard Error: 11.3
Applicability
Crash Type: Angle
Crash Severity: All
Roadway Types: Not specified
Number of Lanes: 2
Road Division Type:
Speed Limit:
Area Type: Rural
Traffic Volume:
Average Traffic Volume:
Time of Day: Not specified
If countermeasure is intersection-based
Intersection Type: Roadway/roadway (not interchange related)
Intersection Geometry: 4-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:
Municipality:
State: MN, MO, NC
Country:
Type of Methodology Used: Before/after using empirical Bayes or full Bayes
Sample Size (crashes): 54 crashes after
Sample Size (sites): 16 sites before, 16 sites after
Other Details
Included in Highway Safety Manual? No
Date Added to Clearinghouse: Jan-17-2017
Comments: CMF for 2-lane at 2-lane intersections. Authors indicated that this CMF is based on small sample size and should be interpreted with caution.