Go back and forth (7)
(Other definitions for shuttle that I've seen before include "Vehicle plying between two points" , "Back-and-forth transport" , "Space vehicle" , "It moves from side to side on the loom" , "Transport plying back and forth" .)
(Other definitions for commute that I've seen before include "make AC/DC split the > daily journey" , "Exchange - travel to work" , "To reduce severity of the punishment" , "Travel into the city to work" , "Travel regularly to work" .)