Abstract Manager

In 2018, UBC and the City of Vancouver published their study on local street traffic circles and their impact on various modes (1). This study showed that traffic circles on local street bikeways posed a higher risk of injury to cyclists and pedestrians.

With the resurgence of traffic calming on local streets in Vancouver post-pandemic, City of Vancouver staff were challenged to find a traffic calming measure that held pedestrian and cyclist safety paramount at the intersection of local street bikeways. Staff reviewed whether traffic circles could be retro-fit with pedestrian and cyclist safety as primary design criteria. Given the space requirements for emergency service vehicles (particularly their turning movements), available funding for traffic calming, and established street widths, retro-fitting traffic circles was not feasible.

Staff explored whether diagonal diverters would be an appropriate traffic-calming measure for the intersection of local street bikeways. Diagonal diverters reduce vehicle volumes on local streets, but have design challenges for bike permeability and emergency access. Because of these constraints, staff did not pursue diagonal diverters for the intersection of two bikeways.

However, staff came across a reference in the The Federal Highway Administration's library to a star diverter (2). Focusing on pedestrian and cyclist safety, then overlaying the other design constraints (emergency services needs, the program budget, existing street width), a modification to the FHWA's star diverter emerged. The modified star diverter prioritizes pedestrian and cyclist safety, allows emergency vehicle permeability, and encourages lower vehicle volumes by diverting vehicles off the bikeways.

The star diverter is built using cast-in-place materials and methodology. The right-of-way is assigned to pedestrians first, then cyclists, as per signage installed on the approach to and within the diverter for cyclists. The star diverter is being installed at the intersection of Charles Street and Lillooet Street in the Hastings-Sunrise (Adanac Overpass) neighbourhood as part of a neighbourhood-wide traffic calming plan (3).

The City of New Westminster is currently considering a star diverter at Tenth Street and London Street intersection as part of its Active Transportation Network Plan implementation.