Patent ID: 7385525

Claim:
A vehicle position determination system for determining a position of a moving vehicle having a transponder in a multi-lane roadway, comprising: two or more antennas having partially overlapped coverage areas, each for transmitting an interrogation signal and receiving a response signal from the transponder; a reader for receiving said response signals from said antennas, said reader including a position determination module for determining the position of the moving vehicle based upon said response signals received by said two or more antennas, wherein said determination is made on expiry of a time period, and a dynamic timing module for determining a current traffic speed associated with the multi-lane roadway and for setting said time period based upon said current traffic speed, wherein said current traffic speed comprises a variable correlated to traffic speed, said dynamic timing module measures said variable correlated to traffic speed, and said variable correlated to traffic speed comprises an average number of response signals per transponder while in said coverage areas.