Abstract Manager

Signalized intersections operating at or above capacity during peak hours often experience significant congestion, with queues on some approaches extending beyond 100 metres. The introduction of a new traffic generator near these locations can further intensify existing mobility and safety challenges. This background forms the basis for our study, which examines how anticipated traffic growth may affect overall network performance. The key issues identified include limited intersection capacity, safety concerns related to high volume turning movements, and the need to maintain accessibility for all road users while accommodating new development. To address these challenges, our objective is to evaluate potential network improvements and determine whether alternative intersection forms, specifically turbo roundabouts, can provide measurable benefits. Our methodology draws on existing planning documentation, observed mobility patterns, and scenario based analysis. Multiple design configurations are being assessed to understand their operational performance, safety implications, and compatibility with local constraints. As part of this evaluation, several fundamental questions guide the assessment of turbo roundabouts: What defines a turbo roundabout? How does it perform relative to a conventional roundabout? What level of design and implementation complexity is involved, particularly for more advanced configurations? Is the layout intuitive for unfamiliar drivers? And importantly, do turbo roundabouts reduce the number and severity of collisions?

To advance the analysis, the presentation will also highlight innovative design features currently in use in the Greater Montréal area but not yet implemented elsewhere in Canada. These include camera activated flashing pedestrian crosswalk signs and a camera based warning system that uses image recognition to activate signage only when vulnerable road users are present, as well as Z shaped pedestrian crosswalks that guide pedestrians toward a splitter island and orient them toward oncoming traffic to improve gap judgment. The review also considers removable lane dividers, which help reinforce lane discipline while supporting winter maintenance. This latter element had been considered for submission to the MTMD standards committee but was not yet advanced. All of these treatments are examined strictly from a research perspective to document some new practices and assess their potential applicability in different contexts.

The conclusions emerging from this work suggest that these enhancements, combined with the inherent operational benefits of turbo roundabouts, have strong potential to improve safety and efficiency both nationally and internationally. By evaluating these design solutions and their impacts on all users, the study aims to determine whether turbo roundabouts offer a reliable, sustainable, and safe alternative to traditional intersections and conventional roundabout designs.