Complex sentence: The signing of the Interstate Highway Act of 1956 helped create a network of more convenient and efficient roadways for motor vehicle travel throughout the country, enticing many more people to travel by car, as well as haul freight by truck rather than by rail.
Split into simpler sentences: The signing of the Interstate Highway Act of 1956 helped create a series more convenient and efficient roadways for automobile travel throughout the country. This enticed many more people to travel by car and in addition promoted the hauling of freight by truck rather than by rail.