A car is privately owned and oriented toward a small scale family/individual. It can go from anywhere to anywhere at anytime (assuming roads). Unlike a railroad which achieves much greater efficiency but requires more fixed schedules and routes. Everyone must move to the same place at the same time together. A lot of this is imagined but people really did buy into this (same with canals), and given the 200 year distrust of railroads, that gave a lot of political fodder to break up urban rail lines and make cities more car based.