What was one effect of the Interstate Highway Act of 1957? 1.)the emergence of the car as America’s main mode of transportation 2.)the creation of speed limits as a result of increased highway accidents 3.)the sluggish development of the airplane industry 4.)an increase in the populations of midwestern and western cities 5.)fewer jobs because the railroads lost business
"4.) an increase in the populations of midwestern and western cities" was an important effect of the Highway Act of 1957, which made travel to these areas much easier.
