CMF / CRF Details

CMF ID: 2753

Install median acceleration lane

Description: Install a median acceleration lane (MAL)

Prior Condition: No Prior Condition(s)

Category: Intersection geometry

Study: NCHRP Report 650 - Median Intersection Design for Rural High-Speed Divided Highways, Maze et al., 2010

Star Quality Rating: 1 Star   [View score details]
Crash Modification Factor (CMF)
Value: 0.77
Adjusted Standard Error:
Unadjusted Standard Error: 0.19
Crash Reduction Factor (CRF)
Value: 23   (This value indicates a decrease in crashes)
Adjusted Standard Error:
Unadjusted Standard Error: 19.3
Crash Type: All
Crash Severity: All
Roadway Types: Principal Arterial Other Freeways and Expressways
Number of Lanes:
Road Division Type: Divided by Median
Speed Limit:
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: 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: 1993 to 2003
Municipality: Pettis County
State: MO
Country: USA
Type of Methodology Used: Simple before/after
Sample Size (crashes): 64 crashes before, 21 crashes after
Other Details
Included in Highway Safety Manual? No
Date Added to Clearinghouse: Mar-21-2011
Comments: For 1 site.