* everything is far apart, intentionally. US cities used to be denser before the car, but in the postwar era not only were there significant amounts of new areas of car-oriented low density, but a lot of the existing dense areas were destroyed, and now in most of the country building traditional density is illegal.
* because everything is far apart and designed for car usage, public transit, walking and cycling are inversely very bad. this simultaneously makes doing any of that dangerous; and it also puts a lot of people on the roads who probably shouldn't be (drunk drivers, distracted drivers, people with failing vision, etc.)
* in some of the worst affected areas, the transport department has applied road standards meant for interstate highways to local roads with traffic lights and no center barriers, and so these roads in particular are quite dangerous and full of rampant speeding
* Americans have tended towards larger cars, and unlike Europe there is no testing in the US for how safe automobiles are for pedestrian impact, so the cars themselves are actually more deadly to pedestrians
* because everything is far apart and designed for car usage, public transit, walking and cycling are inversely very bad. this simultaneously makes doing any of that dangerous; and it also puts a lot of people on the roads who probably shouldn't be (drunk drivers, distracted drivers, people with failing vision, etc.)
* in some of the worst affected areas, the transport department has applied road standards meant for interstate highways to local roads with traffic lights and no center barriers, and so these roads in particular are quite dangerous and full of rampant speeding
* Americans have tended towards larger cars, and unlike Europe there is no testing in the US for how safe automobiles are for pedestrian impact, so the cars themselves are actually more deadly to pedestrians