Abstract Manager

The design of the proposed roundabout at the intersection of Portobello Boulevard and Valin Street in the City of Ottawa illustrated unique challenges in the incorporation of enhanced active transportation measures into a suburban roundabout project.    At several nearby roundabout projects, cycling accommodation had been typically provided via ‘take the lane’ operation through the roundabout or off-road shared-use multi-use pathways around the outside roundabout.  However, given the location of the proposed roundabout within the suburban community, in close proximity to local schools, community centers and a long-term care/retirement facility, significant concerns were raised with the potential for high cycle volumes and interaction with elderly pedestrians with limited mobility within the proposed multi-use pathways.   These concerns, along with the on-going development of dedicated cycling facilities within the City, resulted in a desire for enhanced cycling accommodation at the intersection.

In coordination with the City of Ottawa, Robinson Consultants carried out a re-evaluation of the intersection, including consideration of design and control vehicle accommodations to allow for modifications to the proposed design to support dedicated cycling and pedestrian facilities.   The City of Ottawa had recently developed it’s ‘Protected Intersection Design Guideline’ which provides guidance on the incorporation of dedicated cycling facilities, as well as accessibility measures, into signalized intersection designs, and Robinson Consultants employed the general philosophy and design principles from this guideline to ensure the dedicated cycling facilities were in keeping with the measures utilized at signalized protected intersections to ensure user expectations were consistent throughout the network.  

The resulting design includes a single-lane roundabout with a reduced footprint to support dedicated cycle tracks, pedestrian sidewalks and accessibility measures, and transit accommodation at the proposed roundabout, within a limited property envelope and with considerable utility constraints.  Due to the utility constraints, the redesign of the facility required an adjustment of the inscribed circle diameter which resulted in a non-circular roundabout design.

Detail design of the proposed roundabout has been completed and it is expected that construction will be completed over Summer 2023.