The present invention provides a method of monitoring the position of a vehicle, vessel, rail car, barge, tanker truck that is loaded with bulk or hazardous material. A G.P.S unit is set to send a signal to a radio transmitter if the unit moves beyond a maximum permissible distance (for example, 50 feet...http://www.google.ca/patents/US7868752?utm_source=gb-gplus-sharePatent US7868752 - Method and apparatus for concealing sensors in simulated articles
