Two days after Christmas 1997, an NS mine run is easing down the main leaving Andover. The building and signals on the left are the weigh-in-motion scales, installed in 1969 to replace the single car (one at a time) scale at Andover. By 1997, however, it wasn't needed, so it's out of service. The three lights (plus an audible signal on the radio) advised engineers if their weight speed was acceptable. Green was okay, yellow was slow down, and red---well, you screwed up!