A hydraulic motor of the disc valve type has a disc valve with a plurality of commutation slots that can sequentially register with ports in a port plate as the disc valve is rotated with respect to the port plate. If judging affirmatively, the first wireless station transmits a signal to the second wireless station in synchronization with a signal transmitted by the third wireless station to the fourth wireless station. The account identifier may identify the user to the merchant application. The call is anonymous, so the call setup message does not include caller ID information for the calling party. Once a proper seal is created against the culvert floor, the chamber is dewatered. The probability is based on historical paths taken by vehicles at the decision point as indicated by the vehicle probe data.