CMF / CRF Details

CMF ID: 1583

Install left-turn lane (signal has left-turn phase)

Description:

Prior Condition: No Prior Condition(s)

Category: Intersection geometry

Study: Older Drivers at a Crossroads, Morena et al., 2007

 
Star Quality Rating: 1 Star   [View score details]
Crash Modification Factor (CMF)
Value: 0.27
Adjusted Standard Error:
Unadjusted Standard Error: 0.078
Crash Reduction Factor (CRF)
Value: 73   (This value indicates a decrease in crashes)
Adjusted Standard Error:
Unadjusted Standard Error: 7.8
Applicability
Crash Type: Head on
Crash Severity: All
Roadway Types: Not specified
Number of Lanes:
Road Division Type:
Speed Limit:
Area Type: Urban
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: Signalized
Major Road Traffic Volume:
Minor Road Traffic Volume:
Average Major Road Volume :
Average Minor Road Volume :
Development Details
Date Range of Data Used:
Municipality: Detroit, Grand Rapids
State: MI
Country: usa
Type of Methodology Used: Simple before/after
Sample Size (crashes): 56 crashes before, 15 crashes after
Other Details
Included in Highway Safety Manual? No
Date Added to Clearinghouse: Dec-01-2009
Comments: Applies to head-on and left-turn crashes invilving older drivers (age 65+)