Patent ID: 8255144

Claim:
An accident avoidance system using an infrastructure system to convey position information between vehicles, comprising: a receiver associated with the infrastructure system for receiving vehicle position information acquired onboard position-reporting vehicles and transmitted from the position-reporting vehicles in a vicinity around the infrastructure system, the receiver being located apart from the vehicles; a transmitter coupled to the receiver and fixed at a ground-based station for transmitting to the vehicles in a vicinity of the ground-based station at least a portion of the vehicle position information indicating locations of position reporting vehicles received by the receiver, the transmitter being located apart from the vehicles, the ground-based station being part of the infrastructure system; an accident risk warning system for alerting an operator of a first vehicle of a risk of an accident involving the first vehicle based on the vehicle position information for the first vehicle and map data representing a roadway that the first vehicle is approaching or traveling on including edges or lane boundaries of the roadway; and an active position determining system associated with the infrastructure system for acquiring vehicle position information for non-position-reporting vehicles in the vicinity; wherein the transmitter fixed at the ground-based station is further configured for transmitting position information indicating locations of at least a portion of the non-position reporting vehicles acquired by the active position determining system.