In all the cities I have ever lived in, only one was the type of place that you could use a bike in. The rest were far too large, and your bike would just be too difficult to drag around on public transit.
Amusingly enough, that one city actually tried to incorporate bike racks on the front of buses to encourage people to ride bikes, but it put the buses over the maximum allowable length for city streets and they never determined who should be responsible for any damage to the bike or anything else in the event of an accident. I think there were also issues with the time to load and unload bikes slowing down the bus schedules. Basically the city went to a lot of effort to mire the whole mess in red tape.
Def