A similar wreck, without fatalities, occurred two years ago.
What follows is speculation, and I hope to be shown wrong. The engineer of Saturday's train had recently joined Metra from CSX, which is one of the sloppier big railroads. I wonder if there isn't a pattern of engineers operating trains at track speed despite a restrictive signal, expecting a somewhat harried dispatcher to clear a signal in response to a radio request. Although such a practice is contrary to the rules, it is something I have noticed listening to freight railroad radio chatter. If the usual pattern is to clear the through route upon request, crews might be lulled into a false sense of security until, as sometimes happens, that restrictive signal is properly displayed in advance of an open switch.In both crashes, commuter trains were supposed to switch tracks at a crossover near 47th Street. The speed limit for such a maneuver in that location is 10 m.p.h. Both trains were traveling close to Metra's regular cruising speed of 70 m.p.h. when the accidents occurred, investigators said.
Both crashes also involved engineers who had only recently joined Metra.
Years ago, a practice called "running on the yellows" was a cause of rear-end collisions. The engineer of a train running behind another train might become frustrated by reducing speed for an approach aspect (usually yellow) only to see a clear aspect (green) at the next signal, then having to reduce speed for the next yellow. He might become lulled into the idea that as long as the train ahead continues to run at track speed, he can stay closer to schedule by pushing the yellows at track speed. Works just fine as long as the train ahead doesn't stop with its hind end just beyond the unanticipated stop aspect (red) the preceding yellow is supposed to call attention to.
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