A vehicle includes a contact-position-dependent type operational intention determining unit that detects a change in posture of a rider using posture sensors for a backrest disposed in areas of a backrest with which left and right shoulder blades of the rider come into contact, and thereby determines whether there is an operational intention of the rider; and a left-right amount-of-change comparison type turn intention determining unit that determines, only when it is determined that there is an operational intention, whether there is a left or right turn intention of the rider from a difference between sensor output values located left-right symmetrically.