The very first Highway Travel Information center in the Unites States opened on May 4, 1935 on US-12 at New Buffalo in Berrien County. The structure was built by the Michigan State Highway Department (now M-DOT) to welcome motorists entering from Indiana. Similar travel centers soon began popping up across the nation and there are several hundred still in existence today.
Source: Brandon James, “A ‘Pure’ History Of Michigan Tourism Campaigns“, Magic 104.9, April 17, 2018.