The principal highways in the metropolitan area are Interstate 35 and the MoPac Expressway (State Highway Loop 1), both of which are the primary North/South roadways. Other important arteries in the city and its immediate vicinity are U.S. Highway 183 (also known as "Research Blvd."), and U.S. Highway 290 which provide East/West thoroughfares. Other important highways include State Highway 71 (also known as "Ben White Blvd.") which connects Austin with Houston to the south, and to Marble Falls and the Highland Lakes chain to the west. And State Highway Loop 360 is a scenic highway which runs to the North/South on the west side of Austin but curves westward into the hills. Loop 360 carries special scenic zoning as well preventing billboards and minimizing views of the surrounding buildings. Austin's new toll roads include State Highway 130, U.S. Highway 183-A, and State Highway 45 discussed below. Interstate 10 also runs through the extreme southern portion of Caldwell County.