Here's an article that explains Vancouver's innitiatves to stop urban sprawl:
http://www.planetizen.com/node/25322
Basically, it describes how at first building a network of freeways was nixed. This did not completely kill urban growth because many of the outlying communities in Greater Vancouver did not buy in to it.
Later Vancouver started to disallow room for parking vehicles, building new roads, and even widening existing roads all in an attempt to build higher density neighbourhoods that are more pedestrian friendly than commuter friendly.
There is actually a lot on this if you do a google search. Many cities are using Vancouver as a model is how to densify their urban core.