Your concern is 100% valid but I think what we're headed for in urban areas is something like a free-for-all until the adoption of non-vehicular transportation

Your concern is 100% valid but I think what we're headed for in urban areas is something like a free-for-all until the adoption of non-vehicular transportation gets so high that streets are bifurcated: cars over here, everything else, over here. It's going to be messy, but if Uber has proved anything it's that laws will change to accommodate revolutionary utility.