Because America was built for cars, not pedestrians. You'd be surprised how hard it can be to walk just a block or two down sometimes....

Also in some parts of the country we have ridiculously fast roads right in front of neighborhoods so 3-4 minutes might be at 55mph (88kmh)

There are no sidewalks, bike lanes or even a shoulder on the road. I walked home from the tire shop next to the store one time last year and four people stopped to offer me a ride because it's that dangerous.

Also it's currently way below freezing here. I would still walk in those temps but not many people will, and not everyone can walk two miles each way (which is more like 1-2 hrs of walking total)

Because it's cool