CMF / CRF Details

CMF ID: 61

Increase vertical grade by 1%

Description:

Prior Condition:  No Prior Condition(s)

Category: Alignment

Study: Development of Adjustment Factors for Single Vehicle Run-off-the-road Accident Rates by Horizontal Curvature and Vertical Grade, Miaou, S. P., 1995

 
Star Quality Rating:Cannot Be Rated (Insufficient Information)
Rating Points Total:
Crash Modification Factor (CMF)
Value:1.04
Adjusted Standard Error:
Unadjusted Standard Error:0.02
Crash Reduction Factor (CRF)
Value:-4  (This value indicates an increase in crashes)
Adjusted Standard Error:
Unadjusted Standard Error:2
Applicability
Crash Type:Run off road,Single vehicle
Crash Severity:All
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:
Minimum Speed Limit:
Maximum Speed Limit:
Speed Unit:
Speed Limit Comment:
Area Type:Rural
Traffic Volume:
Average Traffic Volume:
Time of Day:
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:
Municipality:
State:
Country:
Type of Methodology Used:Regression cross-section
Other Details
Included in Highway Safety Manual?Yes. HSM lists this CMF in bold font to indicate that it has the highest reliability since it has an adjusted standard error of 0.1 or less. However, it also includes a caret (^) notation to indicate that the CMF value itself is within the range 0.90 to 1.10 but that the left-hand side or the right-hand side of the confidence interval defined by the CMF ± two times the standard error may be exactly at 1.0. This is important to note since a treatment with such an AMF may result in no change in safety. HSM recommends using this CMF with caution.
Date Added to Clearinghouse:Dec 01, 2009
Comments:

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