Transportation in South Dakota

[1] South Dakota and Montana are the only states sharing a land border which is not traversed by a paved road.

Also located in the state are the shorter interstates 190, a spur into central Rapid City, and 229, a loop around eastern and southern Sioux Falls.

[2] Larger cities served by the route include Watertown, Brookings, Sioux Falls, and Vermillion.

[2] The I-29 corridor features generally higher rates of population and economic growth than areas in eastern South Dakota that are further from the interstate.

[2] I-90, being a major route between western national parks and large cities to the east, brings many out-of-state travelers through South Dakota, thus helping to boost the tourism and hospitality industries.

South Dakota Highway 100 is a planned limited access road in Sioux Falls.

[7] BNSF Railway is currently the largest railroad in South Dakota, primarily operating former Milwaukee Road trackage; the Rapid City, Pierre and Eastern is the state's other major carrier, mostly operating former Chicago & North Western trackage.

Automobiles and buses were much more popular, but there was an upsurge in train use during World War II when gasoline was scarce.