Cities without auto's of any kind are an impossibility. We (and I include cyclists) need goods delivered to merchants, buses and some sort of stability to drive the economy; if every autoworker was out of a job, our taxes would go up substantially and so would the crime rate. Instead, consider this:

First off, cycling must be encouraged. No doubt.

Second, the engines of cars and trucks need to improved in terms of fuel, mileage and emissions (quite a bit, I might add). Auto's need to be designed 'safer' for pedestrians and cyclists (collisions, bumpers etc.). Most important, is the training of drivers and enforcement of safe driving. This is critical.