Remote control locomotives

[schweitzerdude]

While driving in an industrial area of Portland, Oregon,USA, I came across this sign at several unguarded crossings: “Attention. Remote control locomotives operate in this area. Locomotive cab may be unoccupied” One example (yellow sign on crossbuck) can be seen in Google Maps Street View. Didn’t see one operating, but this is new to me. Anyone have any experience or more info on this?
https://maps.google.com/maps?hl=en&ll=45.618504,-122.780352&spn=0.000004,0.002376&t=m&z=19&layer=c&cbll=45.618407,-122.780217&panoid=-J5XsMm8vmX5FLcF9VeqBw&cbp=12,210.35,,0,0

 

[whitepass]

This started back in the 1950's or 1960's on mining railroads were all the track was on privet property.

 

[cascaderailroad]

It's a good thing that prototype RR's do not use AI control !

 

[butter]

Alot of these are yard switchers... I know the CSX NW Ohio Terminal uses one or more SD40-2's with radio control to switch around intermodal cars and building outbound trains.