Advancing the politics of public transportation and public spaces is not easy. Danish architect Jan Gehl and his firm Gehl Architects, however, have a track record of success with cities around the world.
More capacity for the same cost is the case with double-decker commuter cars -- if they can fit into tunnels, that is. Bi-level train were once more common in the commuter trains serving NYC. However, these cars can have their own disadvantages.