CMF / CRF Details

CMF ID: 10127

Install wider edgelines (4 in to 6 in)

Description:

Widen edgelines from 4 inches to 6 inches

Prior Condition:  No Prior Condition(s)

Category: Delineation

Study: Safety Impact of Edge Lines Wider Pavement Markings, Mohamed et al., 2019

 
Star Quality Rating:2 Stars  [View score details]
Rating Points Total:40
Crash Modification Factor (CMF)
Value:0.765
Adjusted Standard Error:
Unadjusted Standard Error:0.091
Crash Reduction Factor (CRF)
Value:23.53  (This value indicates a decrease in crashes)
Adjusted Standard Error:
Unadjusted Standard Error:9.14
Applicability
Crash Type:Nighttime
Crash Severity:K (fatal),A (serious 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:
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:2010 to 2016
Municipality:
State:ID
Country:USA
Type of Methodology Used:Before/after using comparison group
Other Details
Included in Highway Safety Manual?No
Date Added to Clearinghouse:Jul 26, 2019
Comments: The number of crashes in the after period were not reported in this study, however, they have been recorded as 300 to give 10 points as a beneift of doubt for one or more of the following: (1) number of miles/sites in the reference/treatment group, (2) number of crashes in the references/treatment group, (3) reporting AADTs for the aggregate dataset but not for the disaggragate dataset used for CMF development.

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