CMF / CRF Details

CMF ID: 8902

Implement systemic signing and marking improvements at stop-controlled intersections

Description: Double‐up (i.e., both right and left side) 36 in. x 36 in. intersection warning signs (W2- 22 series in the MUTCD (4)) on fluorescent yellow sheeting. Add advance street name plaque (W16‐8 in the MUTCD(4)) on fluorescent yellow 24 sheeting accompanying each right‐side intersection warning sign. Double-up (i.e., both right and left side) 48 in. x 48 in. STOP or YIELD signs (R1‐1 and 26 R1‐2 in the MUTCD(4)). Install retroreflective strips on sign posts for the above signs. Place minor road stop bars within 4 to 10 ft of the edge of the nearest through lane along the major road. Install yield bars at all lanes having yield conditions. Add dashed white edge-lines along the major road through the intersection. Remark all existing stop bars, crosswalks, arrows and word messages unless: o The roadway has been resurfaced within one calendar year and new thermoplastic markings have been applied. o Existing markings are uniformly reflective and above ground thickness is 90 mils or greater. o Otherwise directed by a district representative. Mark all turn lanes to include the pattern of lane arrows and text marking “ONLY” based on the turn lane length.

Prior Condition: Stop-controlled intersections without systemic signing and marking 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]
Crash Modification Factor (CMF)
Value: 0.902
Adjusted Standard Error:
Unadjusted Standard Error: 0.032
Crash Reduction Factor (CRF)
Value: 9.8   (This value indicates a decrease in crashes)
Adjusted Standard Error:
Unadjusted Standard Error: 3.2
Applicability
Crash Type: All
Crash Severity: All
Roadway Types: All
Number of Lanes: 2
Road Division Type:
Speed Limit:
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: Stop-controlled
Major Road Traffic Volume: Minimum of 641 to Maximum of 41731 Annual Average Daily Traffic (AADT)
Minor Road Traffic Volume: Minimum of 102 to Maximum of 8436 Annual Average Daily Traffic (AADT)
Average Major Road Volume : 11042 Annual Average Daily Traffic (AADT)
Average Minor Road Volume : 1453 Annual Average Daily Traffic (AADT)
Development Details
Date Range of Data Used: 2005 to 2014
Municipality:
State: SC
Country:
Type of Methodology Used: Before/after using empirical Bayes or full Bayes
Sample Size (sites): 126 sites before, 126 sites after
Other Details
Included in Highway Safety Manual? No
Date Added to Clearinghouse: Nov-17-2017
Comments: CMF for 2 mainline lanes and 2 cross street lanes stop-controlled 3-legged intersections.