CMF / CRF Details

CMF ID: 4128

Increase lateral clearance from 10 to 40 feet

Description: Lateral clearance is the distance from the roadside to nearby obstructions and fixed objects. The distance measured includes the shoulder, which is consistent with the definition of roadside clearance described by AASHTO.

Prior Condition:  Increase lateral clearance from 10 feet to 40 feet on a rural, two-lane road. The CMF applies to single-vehicle crashes on horizontal curve sections.

Category: Roadside

Study: Investigating the Effect of Roadside Features on Single-Vehicle Roadway Departure Crashes on Rural Two-Lane Roads, Yichuan Peng, Srinivas Reddy Geedipally, and Dominique Lord, 2012

 
Star Quality Rating:3 Stars  [View score details]
Rating Points Total:80
Crash Modification Factor (CMF)
Value:0.49
Adjusted Standard Error:
Unadjusted Standard Error:
Crash Reduction Factor (CRF)
Value:51  (This value indicates a decrease in crashes)
Adjusted Standard Error:
Unadjusted Standard Error:
Applicability
Crash Type:Run off road,Single vehicle
Crash Severity:K (fatal),A (serious injury),B (minor injury),C (possible injury)
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:Undivided
Minimum Speed Limit:
Maximum Speed Limit:
Speed Unit:
Speed Limit Comment:
Area Type:Rural
Traffic Volume:Minimum of 3500 to Maximum of 3500 Average Daily Traffic (ADT)
Average Traffic Volume:3500 Average Daily Traffic (ADT)
Time of Day:All
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:2003 to 2008
Municipality:
State:TX
Country:USA
Type of Methodology Used:Regression cross-section
Sample Size (crashes):197 crashes
Other Details
Included in Highway Safety Manual?No
Date Added to Clearinghouse:Nov 01, 2012
Comments:This CMF applies to single-vehicle run-off-road crashes on horizontal curve sections of rural, two-lane roads. Additional CMFs could be derived from the analysis, but the authors only report the crash reduction for the following conditions: ADT of 3500 vehicles per day and change in lateral clearance from 10 to 40 feet.