Also I am worried where it is stated that D1 does not distinguish between moving objects to be inspected, where as '862 distinguishes between vehicles to be inspected and not be inspected as well as other moving objects. The statement “it does not inspect human, animals.... “ however, D1 will also not inspect humans, animals, etc... (or even a truck that might drive down the track as the sensors will not be triggered[by the way I have driven my hummer along railroad tracks so it can be done, with ease]) , as they will not trigger the magnetic sensors along the track, so in that sense D1 will can distinguish between objects. It is true that there is a single object that triggers the system and that is a train engine, so D1 distinguishes between train engines and all other objects and therefore it will distinguish between classes of objects train engine and not train engine.