superroad

noun

su·​per·​road ˌsü-pər-ˈrōd 

plural superroads

: a very large road

… surveys were started in the 1930s in Indiana for a superroad known as the Tri-State Highway, a tax-financed facility with design standards on a par with toll roads.

—Albert J. Wedeking

Word History

First Known Use

1907, in the meaning defined above