From Longman Dictionary of Contemporary Englishrest areaˈrest ˌarea noun [countable] especially American EnglishDLOTTR a place near a road where you can stop and rest, go to the toilet etc
Examples from the Corpus
rest area• They were in a rest area, with comfortable chairs and sofas arranged round coffee tables.• I pass up a roadside rest area, a happy hunting ground for new cars and ready cash.• Meanwhile, the waiter went straight to the staff rest area and, using a coin phone, dialled his contact. 