I don't know the history of that service area, but Hot Shoppes was the name of a big restaurant/cafeteria chain in the Washington area back in the 50s and 60s. Maybe it wasn't that the service area was called Hot Shoppes, but that Hot Shoppes had the food franchise there? Just a guess....
Hot Shoppes was a chain of cafeterias and drive-ups (something like present-day Sonic) owned by Marriott (who also once owned Sodexho, f/k/a HostMarriott, which was in the turnpike service plaza business).
Back in the 1960's, there was the Hot Shoppers Jr. concept, which was a fast food place, which eventually morphed into Roy Rogers (there's still a Roy Rogers at the Maryland House service plaza).
Getting back to the Hot Shoppes chain, they were once ubiquitous in the Washington, D.C. region, but the last one was closed in 1999 (they were generally well-run (I think they were all owned directly by Marriott,
not franchised), clean, the food was hot and the prices at the Hot Shoppes were right). Marriott has
just announced that they will be bringing the Hot Shoppes brand back to life, with a new one scheduled to open as part of a Marriott hotel in downtown Washington (smart, shrewd move by Marriott, as I think the new Hot Shoppes location will get mobbed).
Images of Hot Shoppes from the 1940's from the George Mason University
here.