The term 'REST STOP SIGHT' can be broken down into three crossword solutions: SEMI (4 letters), AUTOS (5 letters), and BIGRIG (6 letters). A SEMI is a large truck, usually with two trailers, that is used to transport goods over long distances. AUTOS are cars or other motor vehicles. A bigrig is a slang term for a large truck, usually with two trailers, that is used to transport goods over long distances. All of these vehicles can often be seen at rest stops, which are places where drivers can take a break from driving and rest.