The debate over the fate of the Gardiner Expressway, the great mistake of Toronto's 1960's urban planning, has once again come up as hot topic. A study recently made public lays out several options for dealing with the elevated highway slicing through downtown, from leaving it alone, to making it surface level, to burying it.
While burying the monstrosity would yield the best results, it comes with a quite infeasible price tag. Thus, the suggested option is to replace it with a surface level, 10-lane street.
The skeptics to such a plan, generally, have two main complaints: 1) It would be more of a waterfront barrier as you can walk under the Gardiner, but no one will want to cross a 10-lane street; and 2) It will make traffic exponentially worse. Let's rebut these in turn.
The Gardiner is a barrier in several senses. It is partly a barrier in the literal sense, in that it blocks passage from one side to the other in many places. However, where it is elevated and one can walk beneath, it becomes a usability barrier. The Gardiner up in the air, and the ground below it are quite useless to people. One is not permitted to walk upon the Gardiner, and the noise and squallor below make it an uninviting place to stay. You will never find stores and restaurants facing the openness under the Gardiner because no one will want to stay there; it is one long and continuous stretch of blight.
This, in turn, discourages people from crossing it, even if it is physically possible. It's the "wrong side of the tracks" effect. The area at the Gardiner has no use, so areas immediately adjacent will have little use, those adjacent to that will have slightly more use, and so on. The border areas push development away from it, discouraging interaction between the areas they divide.
A surface-level street of the same size, however, is not prone to the same effect if the street itself is designed for use. The model to which the surface-level road would be designed is University Ave. This is a street of the same width, with the same capacity, and yet it is one of the best walkable streets in the city. Landscaped medians provide places of attraction, and wide sidewalks allow freedom of movement and leisure. University Ave, thus, does not act as a barrier between downtown-central and downtown-west, but is a place of use itself, helping to link the two neighbourhoods. The Gardiner replacement can be designed the same way.
The second complaint, that traffic congestion will increase, seems to ignore that people have choice. People can choose to drive, or they can choose another method. The choice they will make will always be based on cost: cost in time, cost in money, cost in convenience, cost in comfort, cost in ethics, etc. If I need to go one block to the corner store, I will walk because it is easier than unlocking my bike or manouvering my car. If I need to go to the financial core, I will bike if the weather's nice because it costs no money, or take the streetcar because there is no place to park. If I have to go out to the suburbs, I will drive because transit service is insufficient out there and it is too far by other means.
The reason why building more roads never eases congestion is because more roads make driving more convenient. Consider the downtown rush-hour commute. If a new highway opens, a lot of transit users will now reconsider, thinking "there's more road and less traffic; it's now faster to drive." Traffic increases until congestion gets so bad that a threshold is reached, and no further people decide to drive; transit remains more convenient for the remaining few.
Similarily, if you were to remove a highway, congestion, at first, would increase dramatically. Commuters then once again reassess their options. The trip takes too long and is too expensive, so some abandon their cars and go for transit, which they have determined to be more convenient and cost-effective for them. Eventually, another threshold is reached and congestion returns to about what it once was. A toll, for example, would further change this threshold as more would then decide that the price is too steep, and make another choice. Choice and cost eventually find an equilibrium.
So, the course of action I see as the right one is to tear the sucker down. Transit must be beefed up (in fact, public transit improvement in general is more important than this single project) so that existing drivers have the option to leave their cars at home, and build us a usable street to which people will gladly flock.