TheTigerMaster
Superstar
Look, removing the Gardiner altogether and not bothering with either a hybrid or tunneled Gardiner is a valid discussion to have. I just prefer a tunneled version to a hybrid if Joe Public says we have to have an express connection between the Gardiner and DVP. If we're tunneling anyway for a DRL, doesn't it stand to reason to direct the money we were going to spend on a lackluster hybrid toward putting the expressway in the same tunnel(s) as the DRL?
The Relief Line is a $3.5 billion project. What you propose can easily add tens of billions of dollars onto the cost. Putting those tens of billions of dollars into public transit would be far more beneficial than spending it on a Gardiner tunnel. Your proposal isn't something that would have a small impact on project costs.
And of course, there are those pesky engineering challenges that are sure to render your proposal physically impossible. How will we get a 30 m diameter tunnel to navigate the very deep basements of downtown buildings? How will on and off ramps be built without tearing down half of downtown Toronto? How will this infrastructure get around the subway, dozens of utility tunnels and pedestrian paths?