Case Study Filter: Speed

Improving Rural Intersection Safety and Efficiency with Dynamic Dilemma Zone Protection: Alabama Pilot Study

Alabama
Rural high-speed intersections in Alabama experienced several benefits, including 24-35% fewer red light-runner crashes, in a pilot of CWA (continuous wide area) sensors used in a dynamic DZP (dilemma zone protection) system.

Rounding Out Roundabouts in CT

Connecticut
Connecticut DOT formed a roundabout committee of professionals trained on evaluating the planning, design, and construction of roundabouts on municipal and state roads.

Case Study in Mitigating Extreme Speeding

Florida
Traditional traffic control devices were failing on high-speed roads in Florida. FDOT saw significant and sustained reductions in extreme speeding after adding speed shields to S.R. 46. The speed shields are an innovative, low-cost countermeasure that delivered immediate and sustained speed reductions.

FDOT’s Application of Target Speed

Florida
FDOT developed a context classification guide for roadway design. Target speeds are determined by many data points, by context classification and for the safe mobility of all users.

Post SS4A Implementation Management for Albany, Georgia

Georgia
GDOT tracks its Comprehensive Safety Action Plan through a website and regular meetings of the SS4A Stakeholder Committee. Monitoring detects tool effectiveness and collects data for future funding opportunities.

High-Speed Lane Separation Project

Michigan
US-31/M-72 had frequent fog, blowing snow, and a severe crash pattern. After adding a center median, edgeline and centerline corrugations, guardrail, new pavement, and a flashing low visibility warning system, the segment had less severe crashes.

Lane Constrictor Intersections in Minnesota

Minnesota
Concerned with rural intersections crashes, MnDOT developed a standard layout of lane constrictors. They installed lane constrictors at 61 side street, stop-controlled locations.

MnDOT Safe System Approach Implementation Plan

Minnesota
The MnDOT Safe System Approach Implementation Plan integrates the SSA into programming. Their process involves an internal SSA implementation workgroup, tools library, speed management guide, training, and updated technical guidance documents.