CMF / CRF Details

CMF ID: 8960

Implement systemic signing and visibility improvements at signalized intersections

Description: Replace all signal heads. Replace pedestrian signal heads, pushbuttons, and signs. Install backplates with retroreflective borders on all signal heads. Re-stripe stop lines. Re-stripe crosswalks. Install advance warning signs. Install overhead signs (e.g., R10‐12, R3‐5L, R3‐5R in the MUTCD(4)). Install curb ramps.

Prior Condition: Signalized intersection without systemic signing and visibility improvements

Category: Intersection traffic control

Study: Safety Effects of Low-Cost Systemic Safety Improvements at Signalized and Stop-Controlled Intersections, Le et al., 2017

Star Quality Rating: 3 Stars   [View score details]
Rating Points Total: 90
Crash Modification Factor (CMF)
Value: 1.104
Adjusted Standard Error:
Unadjusted Standard Error: 0.217
Crash Reduction Factor (CRF)
Value: -10.4   (This value indicates an increase in crashes)
Adjusted Standard Error:
Unadjusted Standard Error: 21.7
Crash Type: Angle
Crash Severity: All
Roadway Types: All
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: All
Traffic Volume:
Average Traffic Volume:
Time of Day: All
If countermeasure is intersection-based
Intersection Type:
Intersection Geometry: 3-leg
Traffic Control: Signalized
Major Road Traffic Volume: Minimum of 4272 to Maximum of 41100 Annual Average Daily Traffic (AADT)
Minor Road Traffic Volume: Minimum of 111 to Maximum of 20000 Annual Average Daily Traffic (AADT)
Average Major Road Volume : 20447 Annual Average Daily Traffic (AADT)
Average Minor Road Volume : 5864 Annual Average Daily Traffic (AADT)
Development Details
Date Range of Data Used: 2005 to 2014
State: SC
Type of Methodology Used: Before/after using empirical Bayes or full Bayes
Sample Size (sites): 5 sites before, 5 sites after
Other Details
Included in Highway Safety Manual? No
Date Added to Clearinghouse: Nov-17-2017
Comments: CMF for right-angle crashes at 2 mainline lanes and 2 cross street lanes 3-legged intersections. 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.