 The original planning maps plotted the first turnpike to the west of Detroit, running near US 24 (Telegraph Road).This route was later proposed for I-75 itself; I-275 would have been the freeway to loop into downtown Detroit.The proposed length was increased by December 1955; the extended Michigan Turnpike would have run from a connection across the Ohio state line to Toledo north through Detroit and Saginaw and eventually to the southern end of the Mackinac Bridge.