Interstate Highway System
The Dwight D. Eisenhower National System of Interstate and Defense Highways, commonly known as the Interstate Highway System, or the Eisenhower Interstate System, is a network of controlled-access highways that forms part of the National Highway System in the United States. The system extends throughout the contiguous United States and has routes in Hawaii, Alaska, and Puerto Rico.
"Interstate" redirects here. For the type of highway, see Controlled-access highway. For other uses, see Interstate (disambiguation).
In the 20th century, the United States Congress began funding roadways through the Federal Aid Road Act of 1916, and started an effort to construct a national road grid with the passage of the Federal Aid Highway Act of 1921. In 1926, the United States Numbered Highway System was established, creating the first national road numbering system for cross-country travel. The roads were state-funded and maintained, and there were few national standards for road design. United States Numbered Highways ranged from two-lane country roads to multi-lane freeways. After Dwight D. Eisenhower became president in 1953, his administration developed a proposal for an interstate highway system, eventually resulting in the enactment of the Federal-Aid Highway Act of 1956.
Unlike the earlier United States Numbered Highway System, the interstates were designed to be all freeways, with nationally unified standards for construction and signage. While some older freeways were adopted into the system, most of the routes were completely new. In dense urban areas, the choice of routing destroyed many well-established neighborhoods, often intentionally as part of a program of "urban renewal".[3] In the two decades following the 1956 Highway Act, the construction of the freeways displaced one million people,[4] and as a result of the many freeway revolts during this era, several planned Interstates were abandoned or re-routed to avoid urban cores.
Construction of the original Interstate Highway System was proclaimed complete in 1992, despite deviations from the original 1956 plan and several stretches that did not fully conform with federal standards. The construction of the Interstate Highway System cost approximately $114 billion (equivalent to $618 billion in 2023). The system has continued to expand and grow as additional federal funding has provided for new routes to be added, and many future Interstate Highways are currently either being planned or under construction.
Though heavily funded by the federal government, Interstate Highways are owned by the state in which they were built. With few exceptions, all Interstates must meet specific standards, such as having controlled access, physical barriers or median strips between lanes of oncoming traffic, breakdown lanes, avoiding at-grade intersections, no traffic lights, and complying with federal traffic sign specifications. Interstate Highways use a numbering scheme in which primary Interstates are assigned one- or two-digit numbers, and shorter routes which branch off of longer ones are assigned three-digit numbers where the last two digits match the parent route. The Interstate Highway System is partially financed through the Highway Trust Fund, which itself is funded by a combination of a federal fuel tax and transfers from the Treasury's general fund.[5] Though federal legislation initially banned the collection of tolls, some Interstate routes are toll roads, either because they were grandfathered into the system or because subsequent legislation has allowed for tolling of Interstates in some cases.
As of 2020, about one quarter of all vehicle miles driven in the country used the Interstate Highway System,[6] which had a total length of 48,756 miles (78,465 km).[2] In 2020 and 2021, the number of fatalities on the Interstate Highway System amounted to more than 5,000 people annually.[7]
Impact and reception[edit]
Following the passage of the Federal Aid Highway Act of 1956, passenger rail declined sharply as did freight rail for a short time, but the trucking industry expanded dramatically and the cost of shipping and travel fell sharply.[107] Suburbanization became possible, with the rapid growth of larger, sprawling, and more car dependent housing than was available in central cities, enabling racial segregation by white flight.[108][109][110] A sense of isolationism developed in suburbs, with suburbanites wanting to keep urban areas disconnected from the suburbs.[108] Tourism dramatically expanded, creating a demand for more service stations, motels, restaurants and visitor attractions. The Interstate System was the basis for urban expansion in the Sun Belt, and many urban areas in the region are thus very car-dependent.[111] The highways may have contributed to increased economic productivity in, and thereby increased migration to, the Sun Belt.[112] In rural areas, towns and small cities off the grid lost out as shoppers followed the interstate and new factories were located near them.[113]
The system had a profound effect on interstate shipping. The Interstate Highway System was being constructed at the same time as the intermodal shipping container made its debut. These containers could be placed on trailers behind trucks and shipped across the country with ease. A new road network and shipping containers that could be easily moved from ship to train to truck, meant that overseas manufacturers and domestic startups could get their products to market quicker than ever, allowing for accelerated economic growth.[114] Forty years after its construction, the Interstate Highway system returned on investment, making $6 for every $1 spent on the project.[115] According to research by the FHWA, "from 1950 to 1989, approximately one-quarter of the nation's productivity increase is attributable to increased investment in the highway system."[116]
The system had a particularly strong effect in Southern states, where major highways were inadequate. The new system facilitated the relocation of heavy manufacturing to the South and spurred the development of Southern-based corporations like Walmart (in Arkansas) and FedEx (in Tennessee).[114]
The Interstate Highway System also dramatically affected American culture, contributing to cars becoming more central to the American identity. Before, driving was considered an excursion that required some amount of skill and could have some chance of unpredictability. With the standardization of signs, road widths and rules, certain unpredictabilities lessened. Justin Fox wrote, "By making road more reliable and by making Americans more reliant on them, they took away most of the adventure and romance associated with driving."[114]
The Interstate Highway System has been criticized for contributing to the decline of some cities that were divided by Interstates, and for displacing minority neighborhoods in urban centers.[3] Between 1957 and 1977, the Interstate System alone displaced over 475,000 households and one million people across the country.[4] Highways have also been criticized for increasing racial segregation by creating physical barriers between neighborhoods,[117] and for overall reductions in available housing and population in neighborhoods affected by highway construction.[118] Other critics have blamed the Interstate Highway System for the decline of public transportation in the United States since the 1950s,[119] which minorities and low-income residents are three to six times more likely to use.[120] Previous highways, such as US 66, were also bypassed by the new Interstate system, turning countless rural communities along the way into ghost towns.[121] The Interstate System has also contributed to continued resistance against new public transportation.[108]
The Interstate Highway System had a negative impact on minority groups, especially in urban areas. Even though the government used eminent domain to obtain land for the Interstates, it was still economical to build where land was cheapest. This cheap land was often located in predominately minority areas.[111] Not only were minority neighborhoods destroyed, but in some cities the Interstates were used to divide white and minority neighborhoods.[108] These practices were common in cities both in the North and South, including Nashville, Miami, Chicago, Detroit, and many other cities. The division and destruction of neighborhoods led to the limitation of employment and other opportunities, which deteriorated the economic fabric of neighborhoods.[120] Neighborhoods bordering Interstates have a much higher level of particulate air pollution and are more likely to be chosen for polluting industrial facilities.[120]
