Abstract Manager

Mini-roundabouts can serve as an alternative to stop signs as a traffic control device in a residential neighbourhood and also act as a traffic calming measure to manage speed. However, due to limited design guidance for mini-roundabouts and a lack of installation precedents, many municipalities may not consider their use as a potential traffic control device, even when feasible.

As part of our investigation, we will look at existing mini-roundabouts or pilot projects in various municipalities across Canada, whether implemented as part of a new subdivision or as a retrofit. We will identify design elements and the traffic context (where applicable) at these locations to find trends. We will consider design elements, including central island diameter, landscaping, splitter islands (mountable vs not mountable), and signage, as applicable. We will share responses from municipal staff from these respective mini-roundabout locations to understand whether they find the application of mini-roundabouts and specific design elements effective for road users and roadway maintenance, particularly for plowing operations in winter months. Where applicable, the existing municipal mini-roundabout standards will be discussed.

This presentation aims to increase understanding of mini-roundabouts and identify general insights and guidance for their application. We have found examples where snow plows consistently hit the splitter islands at the mini-roundabout, locations where driveways were blocked by splitter islands or curb extensions and where speeds were not reduced. Poor installations erode the public’s confidence in the mini-roundabout as an effective measure and cause municipalities to stop using them in their toolbox. In other locations, the mini-roundabout is an established tool that is included in many neighbourhood designs.

Our review of existing mini-roundabouts or pilot projects for mini-roundabouts will identify barriers to successful implementation and elements that lead to effective installations. We will discuss the selection of design elements that can assist municipalities not implementing mini-roundabouts, whether as part of a new subdivision or as a retrofit within the existing road right-of-way. We will also discuss location considerations related to traffic volumes, posted speed, roadway widths, neighbourhood types, driveway proximity, on-street parking and transit use.