Downtown Tunnel: In 2013, the City of Ottawa and the Province of Ontario agreed to a new initiative by co-funding a $750,000 engineering feasibility study for a downtown tunnel to connect Highway 417 to the Macdonald-Cartier Bridge (not a tunnel under the Ottawa River).
In August 2016 the Study results were released. This Study examined several possible routes for a 417 to Macdonald-Cartier bridge tunnel and concluded that a tunnel was technically feasible. The recommended route for a tunnel would locate its southern portal near the Vanier Parkway at Coventry Rd and continue under the Rideau River, East Sandy Hill, East Lowertown with the northern portal at the southern end of the Macdonald-Cartier bridge.
The proposed tunnel would be 3.4km long, would in fact be 2 separate tunnels (one for each direction of travel), with 2 lanes in each tunnel. The cost was estimated at between 1.7B$ and 2.0B$ (2015$). It was estimated that if the tunnel existed in 2016 that it would carry approximately 1700 trucks and 20,000-25,000 cars per day. During the peak afternoon period the car traffic would approach 1400 vehicles per hour and a forecast was made that this would increase to 2500 vehicles per hour by 2031. Unfortunately the Study did not provide any forecast for how much additional truck traffic the tunnel would carry by 2031.
Ottawa City Council on Sep 14, 2016 voted 21-2 to set aside 2.5m$ in the 2017 budget for a detailed environmental assessment (EA) for this tunnel and commissioned the Mayor to approach the provincial and federal governments to also contribute to the funding of the EA on a 1/3 basis.