Interstate 170 is a former designation for a short freeway spur in Baltimore, Maryland, that is now designated as part of U.S. Highway 40. Under the proposed routing of the Interstate Highways through Baltimore, Interstate 70 would have been routed through West Baltimore to join Interstate 95, and Interstate 170 would have been a spur from Interstate 70 into central Baltimore. However, the spur was left stranded from the rest of the interstate system by the cancellation of Interstate 70 within the city limits of Baltimore. In the early 1980's, it was proposed to connect the spur to Interstate 95 through a proposed Interstate 595; however, that project was canceled as well, and the designation "Interstate 595" was assigned to a different highway in Maryland (it now exists as a secret route for U.S. Highway 50 between the Capital Beltway and Annapolis). More information is available in the article on Interstate 70.