Most US cities require cars, but these are walkable + transit-friendly: 1) NYC — best US subway, walk Manhattan; 2) Boston — T subway, walking-friendly; 3) DC — Metro, Capital Bikeshare; 4) Chicago — L train + buses; 5) San Francisco — cable cars, BART, Muni; 6) Philadelphia — SEPTA, walkable historic core; 7) Portland OR — MAX light rail; 8) New Orleans — streetcars, walking French Quarter; 9) Seattle — light rail, downtown walkable; 10) Honolulu — bus, beach areas walkable. Tips: stay near transit hub or walking-distance from attractions, use Lyft/Uber for late nights, day passes save money. Pittsburgh, Minneapolis, Miami Beach (no real Miami) also feasible but car eases longer trips.