CMF / CRF Details

CMF ID: 10122

Increase density of access points

Description: Safety effects on of spacing of access points (intersections and driveways) along a roadway segment

Prior Condition:  Access spacing greater than 2,640 ft

Category: Access management

Study: Examining Safety on Two-Lane and Multilane Highways in Consideration of Access Spacing, Hamzeie et al., 2019

Star Quality Rating:3 Stars  [View score details]
Rating Points Total:105
Crash Modification Factor (CMF)
Adjusted Standard Error:
Unadjusted Standard Error:0.049
Crash Reduction Factor (CRF)
Value:-17.2  (This value indicates an increase in crashes)
Adjusted Standard Error:
Unadjusted Standard Error:4.9
Crash Type:Other
Crash Severity:All
Roadway Types:Not specified
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:
Minimum Speed Limit:15
Maximum Speed Limit:65
Speed Unit:mph
Speed Limit Comment:
Area Type:Not specified
Traffic Volume:Minimum of 10 to Maximum of 18800 Annual Average Daily Traffic (AADT)
Average Traffic Volume:2482 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 2016
Type of Methodology Used:Regression cross-section
Sample Size (miles):5795 miles
Sample Size (mile-years):28975 mile-years
Other Details
Included in Highway Safety Manual?No
Date Added to Clearinghouse:Jul 26, 2019
Comments:Non-animal crashes. CMF for changing access point spacing greater than 2640ft to 1320-2640ft.