CMF / CRF Details

CMF ID: 4130

Improve sideslope rating from 5 to 1

Description: Side slope ratings were assigned on a five-point scale. 1 = Little grade, if any; generous area to correct for vehicles leaving the traveled-way. 2 = Some rise or fall with low grade, but still highly correctible at highway speeds. 3 = Definite rise or fall with moderate grade, (e.g., drainage 1 ditch), probably not correctible at moderate to high speeds, good possibility for non-injury. 4 = Definite rise or fall with high grade and possible guardrail, similar to bridge over a shallow creek: not correctible, and high chance of non-incapacitating injury at highway speed. 5 = High grade and significant elevation change, such as a cut into a cliff; not correctible and high chance of fatal or incapacitating injury at highway speed.

Prior Condition:  Improve sideslope rating from 5 to 1 on a rural, two-lane road. The CMF applies to single-vehicle crashes on horizontal curve sections. Side slope ratings were assigned on a five-point scale where 1 = little grade, if any, and generous area to correct for vehicles leaving the traveled-way and 5 = high grade and significant elevation change, such as a cut into a cliff; not correctible and high chance of fatal or incapacitating injury at highway speed.

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:0.1
Adjusted Standard Error:
Unadjusted Standard Error:
Crash Reduction Factor (CRF)
Value:90  (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 sideslope rating from 5 to 1.