1. A map matching method for a vehicle safety warning system (VSWS), the method comprising: determining if intelligent transportation system (ITS) map data is available; determining a vehicle location and a vehicle heading; determining an envelope area around a road feature defined by the ITS map data; determining a segment heading for a segment of the road feature; determining a separation distance between the vehicle location and the segment if the vehicle location is located within the envelope area, the segment heading is substantially similar to the vehicle heading, and optionally, the segment elevation is substantially similar to the vehicle elevation; and map matching the vehicle location to the segment if the separation distance is less than a threshold.