CMF / CRF Details

CMF ID: 2767

Install offset right turn lane

Description: Install offset right turn lane to improve sight distance for vehicles on minor road

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]
Rating Points Total:10
Crash Modification Factor (CMF)
Value:1.39
Adjusted Standard Error:
Unadjusted Standard Error:1.01
Crash Reduction Factor (CRF)
Value:-39  (This value indicates an increase in crashes)
Adjusted Standard Error:
Unadjusted Standard Error:101.2
Applicability
Crash Type:All
Crash Severity:O (property damage only)
Roadway Types:Principal Arterial Other Freeways and Expressways
Street Type:
Minimum Number of Lanes:
Maximum Number of Lanes:
Number of Lanes Direction:
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: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:Minimum of 10000 to Maximum of 11300 Annual Average Daily Traffic (AADT)
Minor Road Traffic Volume:Minimum of 2305 to Maximum of 2450 Annual Average Daily Traffic (AADT)
Average Major Road Volume :
Average Minor Road Volume :
Development Details
Date Range of Data Used:2000 to 2005
Municipality:Muscatine
State:IA
Country:USA
Type of Methodology Used:Simple before/after
Sample Size (crashes):4 crashes before, 4 crashes after
Other Details
Included in Highway Safety Manual?No
Date Added to Clearinghouse:Mar 21, 2011
Comments:For 2 approaches. Authors note that the increase in crashes may be attributed to the horizontal curvature of the road near the site and very narrow median width which does not profivde sufficient space for one-stage crossing manuveurs.