CMF / CRF Details

CMF ID: 11141

Coordinated Ramp Metering


Prior Condition:  Ramp without ramp metering

Category: Advanced technology and ITS

Study: Before-After Safety Evaluation of Coordinated Ramp Metering System using Empirical Bayes Approach: A Case Study on I-80 in California, Amirarsalan Mehrara Molan, Anurag Pande, and Stuart Madison Harvey, 2022

Star Quality Rating:3 Stars  [View score details]
Rating Points Total:75
Crash Modification Factor (CMF)
Adjusted Standard Error:
Unadjusted Standard Error:
Crash Reduction Factor (CRF)
Value:24  (This value indicates a decrease in crashes)
Adjusted Standard Error:
Unadjusted Standard Error:
Crash Type:All
Crash Severity:K (fatal),A (serious injury),B (minor injury),C (possible injury)
Roadway Types:Principal Arterial Interstate
Street Type:Two-Way
Minimum Number of Lanes:8
Maximum Number of Lanes:10
Number of Lanes Direction:Both Directions
Number of Lanes Comment:
Crash Weather:Not specified
Road Division Type:Divided by Median
Minimum Speed Limit:
Maximum Speed Limit:
Speed Unit:
Speed Limit Comment:
Area Type:Not specified
Traffic Volume:
Average Traffic Volume:187173 Annual Average Daily Traffic (AADT)
Time of Day:Not specified
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:2012 to 2019
Type of Methodology Used:
Other Details
Included in Highway Safety Manual?No
Date Added to Clearinghouse:Aug 25, 2022
Comments:In the spatial analysis, each segment was classified into type 1 and type 2. Type 1: segments that have an entrance ramp (on-ramp) within the segment or on the segment immediately downstream. Type 2: the remaining segments. This is the CMF of the KABC crashes for type 1 segments.