Highway 17 — McTavish Interchange Project

Design Evolution

The interchange design being prepared for construction is the result of extensive study, as well as consultation with key stakeholders including local municipalities, the Victoria Airport Authority and area residents.

Previous concepts considered included a simply “flyover”, a “tight diamond” interchange (click here) as well as an alternative diamond interchange, an “ultimate flyover”, a “single point” interchange and a difference twin-roundabout design (click here).

Following the public open house held in June 2009, the Transit-Twin Roundabout design was further developed to address issues and concerns identified during the consultation process. The following table summarizes the key issues raised, and how they are being addressed.

Issue How Addressed

Connectivity of McTavish and local road network
  • While some designs considered removing direct access from Highway 17 to McTavish to the west, the final design maintains all connections

Transit features
  • Park & Ride and transit exchange are expanded
  • Special provision is made for rapid transit (Rapid Bus)

Noise & aesthetics
  • Roundabout design reduces the start-and-stop noise and pollution associated with signals in a diamond configuration
  • Noise monitoring has been performed; design incorporates landscaping, berming & pavement technology to minimize exposure as much as possible

Property impacts
  • Design requires minimal property purchase
  • Some accesses will require adjustment to right in / right out for safety
  • Precondition surveys being undertaken by the Ministry to help assess and limit any potential for property damage

Traffic during construction
  • Two major closures for the duration of construction; otherwise traffic flow to be maintained with minor interruptions
  • Project working with North Saanich, McTavish Interchange Task Force and others to identify opportunities to minimize impacts
  • BC Transit to provide construction shuttle service on Lochside between Sidney & Saanichton; Route 82 frequency to be improved during construction period.

Pedestrian / Cyclist accommodation
  • Significant improvement over preliminary design with elimination of circuitous routes & tunnels
  • Introduction of cycling / pedestrian overpass
  • Lochside Trail to be maintained with ability for north-south cyclists to completely bypass roundabout

Acceptance/understanding of roundabouts; complexity for wayfinding
  • Special attention to be paid to good, easily-followed signage
  • Information to be made available to visitors arriving via the airport
  • Increased public information & training opportunities being provided

Robustness  of roundabout design
  • Computer modelling confirms the design will perform effectively through the 2035 planning horizon

Safety of roundabouts
  • Industry data confirms crash frequency and severity is significantly reduced with roundabouts