If driving wasn’t an option, you wouldn’t live 30 miles away from your job. Driving was an option, so you did and so did your neighbors. More neighbors move in, more cars, more traffic, more lanes, more neighbors, more cars, etc.
Alternatively, you move closer to work in a town with half decent sidewalks and walk or bike in. Bikes and people take up much less space which allows things to be closer together.
And yes, cars are necessary for hauling large objects over long distances, but how many vehicles in this photo do you think are carrying more than just people?