trucks were first used extensively by the military during world war i. with the increase in construction of paved roads, trucking began to achieve a significant foothold in the 1930s. public safety concerns made it necessary to implement various government regulations (such as the 1965 hours of service rule; recently revised with a compliance date of july 1, 2012) of how long drivers were allowed to work and drive each day/week. in 1956, taxpayers provided funds to build the interstate highway system, an extensive network of highways and freeways that linked major cities across the continent. the addition of interstate highway system also made it possible for the trucking industry to grow substantially in the late 1950s and early 1960s and trucking has come to dominate the freight industry in the latter portion of the 20th century.