The Aurora (BNSF) Line of Metra is triple track, with the center track being an express track with no platform. A fence separates the two tracks on the south side from the track on the north side. The South platform is generally for inbound trains heading toward Chicago, and the North platform is generally for outbound trains coming from Chicago. (The station building and heated shelters are on the South side, which is logical because it's rare that anyone would need to wait on the North platform after arriving from Chicago.)
While waiting on the South platform for our Chicago-bound train, I looked east (toward Chicago) and said to Cheryl, "I wonder how they're going to get our train in here -- there's a track crew with equipment working on the line down there." Now, I've seen crews clear pretty quickly, but the amount of heavy equipment on the line didn't look as though it could clear in time -- our train was due within five minutes. I wondered if they were planning on trying to bring the train in on the center track and have people cross the tracks -- a mildly dangerous and tricky maneuver, and nearly impossible for anyone with walking difficulty.
I walked a bit down the platform and looked back to the west. The platform was full of people, many wearing Cubs colors and probably heading for that afternoon's game. Then I noticed the scrolling electronic sign under which I had been standing. It was scrolling a message (approximately): "The next train to Chicago will arrive on the North platform."
Yow! I pointed this out to Cheryl, and we started walking back to the center of the platform where the stairs and ramps for accessing the passenger subway under the tracks is. I called out to the crowd on the platform, "Hey, look!" -- pointing to the message sign -- "The next Chicago train is coming in on the other platform!"
Hubbub ensued. Maybe two-thirds of the people read the board and followed us through the underpass. The rest stayed put. I expect they didn't believe the sign, and trains for Chicago always arrive on the South platform, so why should they believe some lunatic babbling on about trains -- besides, he's wearing a Giants hat anyway, so you know you can't trust him.
Coming up to the North platform, I had a bit of a worry when I saw a train's headlights approaching on the center track, but to my relief, I then saw that it was a BNSF freight train. Shortly thereafter, the Metra commuter train approached. I suppose the folks on the South platform then realized that, Giants fan or not, I knew what I was talking about and sprinted for the other platform. I couldn't see whether or not we left anyone behind, because the passing freight train blocked our view of the other platform.
As we pulled away, the freight train cleared, and I could see the bright light of a thermite welder in use -- the track crew must have been replacing a rail.
We called at the next station, Naperville, on the "wrong" platform as well. Again, you could see a crowd of people dashing to get where they should be. Finally we switched back to the regular inbound track and the rest of the trip passed uneventfully.
I am unimpressed with Metra's communication here. Unless that was an emergency repair -- which it may have been; the evidence supports a broken rail -- they should have done a better job of letting passengers know they needed to use the "wrong" platform. Audible announcements in addition to the scrolling message board should have been made, if they can do so. They should not have depended on a random railfan from California to spot that something was amiss and give those people who would listen directions to catch their train.
In many cases, most of Caltrain's announcements and scrolling message boards have been not terribly useful, but I think in a similar situation, we would have heard numerous announcements about the disruption. At least I hope we would have done so.
(See, trinsf? I can write good things about Caltrain!)