Intersection Safety Case Studies

A series documenting successful intersection safety treatments and the crash reductions that were experienced. The nine case studies are:

Stop Sign-Controlled Intersections: Enhanced Signs and Markings – A Winston-Salem Success Story (FHWA-SA-09-010)
The following case study showcases four successful and effective low-cost strategies that measurably improved safety at stop sign-controlled intersections in Winston-Salem, NC.
Retroreflective Borders on Traffic Signal Backplates – A South Carolina Success Story (FHWA-SA-09-011)
The following case study showcases a successful and effective low-cost treatment that measurably improved safety at three signalized intersections in Columbia, South Carolina (SC).
Removal of Signal Flashing Mode During Late-Night/Early-Morning Operation (FHWA-SA-09-012)
The following case study showcases a successful and effective low-cost strategy that measurably improved safety at eight signalized intersections in Winston-Salem, NC.
Minnesota Roundabout – A Scott County Success Story (FHWA-SA-09-013)
The following case study showcases the measurable safety benefits experienced by Scott County, Minnesota, following conversion of a high-speed rural, two-way stop-controlled intersection to a roundabout.
Improving Safety by Providing All-Red Clearance Intervals and Larger Signal Lenses (FHWA-SA-09-014)
The following case study showcases two successful low-cost strategies that measurably improved safety at 33 signalized intersections in Detroit and Highland Park, MI.
Permissive/Protected Left Turn Phasing (FHWA-SA-09-015)
The following case study showcases a successful and effective low-cost countermeasure that measurably improved safety at three signalized intersections in Michigan.
Continuous Green T-Intersections (FHWA-SA-09-016)
The following case study showcases two rural intersections in Colorado where the signal-controlled through lane on the flat side (top) of a T-intersection was converted to a CGT.
Reducing Late-Night/Early Morning Intersection Crashes By Providing Lighting (FHWA-SA-09-017)
The following case study showcases the results of three studies which examined lighting enhancements at more than 50 intersections in Minnesota and Kentucky, installed to reduce crashes associated with poor visibility at intersections during late-night/early-morning hours.
Roundabouts – The Maryland Experience A Maryland Success Story (FHWA-SA-09-018)
The following case study presents selected findings from a study conducted by the Maryland State Highway Administration (MDSHA) that evaluated the safety benefits of modern roundabout intersections compared to two-way stop-controlled intersections. Maryland has more than 60 roundabouts in operation.