Complex sentence: In some other states handicapped parking meters exist, which not only must be paid at the same rate as regular meters, but one will also be subject to receiving a violation ticket if a valid handicap license plate or placard is not displayed on the vehicle.
Split into simpler sentences: In some other states accessible-designated parking meters exist, which, unless the permit holder is exempt, must be paid at the same rate as non-designated meters. One will also be subject to receiving a violation ticket if a valid disability license plate or placard is not displayed on the vehicle.