CMF / CRF Details

CMF ID: 5646

Install edgeline pavement markings on narrow, rural, two-lane roads

Description: Install edgeline pavement markings on narrow (less than 22 ft.), rural, two-lane roads.

Prior Condition: No edge lines

Category: Delineation

Study: Investigating Safety Impact of Edge Line on Narrow Rural 2-lane Highways by Empirical Bayes Method, Sun et al., 2014

Star Quality Rating: 2 Stars   [View score details]
Rating Points Total: 70
Crash Modification Factor (CMF)
Value: 0.85
Adjusted Standard Error:
Unadjusted Standard Error: 0.039
Crash Reduction Factor (CRF)
Value: 15   (This value indicates a decrease in crashes)
Adjusted Standard Error:
Unadjusted Standard Error: 3.9
Crash Type: All
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:
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: 2005 to 2011
State: LA
Country: United States
Type of Methodology Used: Before/after using empirical Bayes or full Bayes
Sample Size (crashes): 986 crashes before, 852 crashes after
Sample Size (sites): 9 sites before, 9 sites after
Sample Size (site-years): 27 site-years before, 27 site-years after
Sample Size (miles): 109 miles before, 109 miles after
Sample Size (miles): 329 mile-years before, 329 mile-years after
Other Details
Included in Highway Safety Manual? No
Date Added to Clearinghouse: Aug-12-2014
Comments: This CMF is for narrow 2-lane rural roads.