CMF / CRF Details

CMF ID: 3411

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:125
Crash Modification Factor (CMF)
Value:1.07
Adjusted Standard Error:
Unadjusted Standard Error:0.0391
Crash Reduction Factor (CRF)
Value:-7  (This value indicates an increase in crashes)
Adjusted Standard Error:
Unadjusted Standard Error:3.91
Applicability
Crash Type:All
Crash Severity:All
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:Minimum of 6777 to Maximum of 37112 Average Daily Traffic (ADT)
Average Traffic Volume:
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:1997 to 2006
Municipality:
State:MO,PA
Country:U.S.A.
Type of Methodology Used:Before/after using empirical Bayes or full Bayes
Sample Size (crashes):1454 crashes before, 934 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).