Spamming bus stations is the easiest way to get mass transit going. Mass transit also helps, but again there is a tendency for Sims to ignore it.
Don't just have an industrial third, commercial third and residential third to your city, have several zones dotted around. The only way around this is decentralisation. This leads to some rather illogical travel paths where Sims will take the overburdened street and ignore your empty 6 lane highway right next to it. In plain SimCity 4, Sims will take the shortest route by distance to their location.
