Rapid transit is a term used to describe transportation systems that move people quickly and efficiently. The three crossword solutions for the term rapid transit are CANOE (5 letters), SST (3 letters), and RIVERRAFT (9 letters). CANOE stands for Canadian North-South Express, which is a high-speed rail line connecting Toronto and Ottawa. SST stands for Supersonic Transport, which is an aircraft that can travel faster than the speed of sound. Finally, RIVERRAFT is a type of boat that is designed to travel quickly on rivers.