CMF / CRF Details

CMF ID: 3606

Install shoulder rumble strips

Description:

Prior Condition:  No Prior Condition(s)

Category: Shoulder treatments

Study: NCHRP Report 641: Guidance for the Design and Application of Shoulder and Centerline Rumble Strips, Torbic et al., 2009

 
Star Quality Rating:4 Stars  [View score details]
Rating Points Total:120
Crash Modification Factor (CMF)
Value:0.62
Adjusted Standard Error:
Unadjusted Standard Error:0.1371
Crash Reduction Factor (CRF)
Value:38  (This value indicates a decrease in crashes)
Adjusted Standard Error:
Unadjusted Standard Error:13.71
Applicability
Crash Type:Run off road
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:Undivided
Minimum Speed Limit:
Maximum Speed Limit:
Speed Unit:
Speed Limit Comment:
Area Type:Rural
Traffic Volume:Minimum of 948 to Maximum of 9067 Average Daily Traffic (ADT)
Average Traffic Volume:
Time of Day:Night
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:1997 to 2006
Municipality:
State:PA
Country:U.S.A.
Type of Methodology Used:Before/after using empirical Bayes or full Bayes
Sample Size (crashes):60 crashes before, 22 crashes after
Other Details
Included in Highway Safety Manual?No
Date Added to Clearinghouse:Mar 21, 2011
Comments:The authors collected data on thru lanes and speed limits but did not provide those data in the report (see p. 50).