Recognizing the need for improved intersection safety, the Capitol Region Council of Governments (CRCOG) engaged VHB to conduct a comprehensive roundabout feasibility study in Connecticut’s Capitol Region. Unprecedented in New England, this effort included 38 municipalities and approximately 43,000 intersections—a first for CRCOG, and one of only three similar studies in the nation at the time.
VHB was tasked with identifying intersections where single-lane roundabouts can enhance safety and traffic operations. The study employed a five-step methodology: intersection location identification, crash review, traffic volume screening, intersection geometry review, and desktop constructability reviews. Data analytics in the screening process allowed for an automated screening effort and established a replicable method for future projects. This study preceded a Connecticut Department Of Transportation statewide screening study, which is currently in progress.
Using an advanced GIS application tool to integrate data from the CRCOG Regional Transportation Safety Plan (RTSP) and the Connecticut Roadway Safety Management System (CRSMS), the team filtered the initial 43,000 intersections to approximately 8,000 potential roundabout candidate locations. Of these, through additional screening efforts and continued location filtering, more than 200 high-potential roundabout intersections were desktop-reviewed.
The final report highlighted the top 100 potential roundabout sites, the top three locations per community, and sites suggested by CRCOG municipalities. This study equips CRCOG with vital information to support its communities in implementing roundabout projects, ultimately fostering safer intersections across the region.
