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Posted by Zak Stambor
How does Metro calculate train arrival times? It’s definitely not accurate—I’ve timed it!

Metro knows their passenger information display system monitors (PIDS) don’t match the actual train arrival times. Rather, the signs show Metro’s train schedule.

As long as Metro trains remain on automatic control (i.e., the driver doesn’t actually take over the controls) and there’s no delays due to passengers cramming into trains, a train malfunction, or other factors, the PIDS is accurate, says Metro spokesman Cathy Asato.

But even though PIDS don’t show the trains’ actual locations, Metro does monitor every train at Metro’s operations control center at its downtown headquarters, at Sixth and F streets NW.

So why don’t they display trains’ actual arrival times?

The PIDS system, which has been in place since October 2000, cannot handle real-time changes, according to Asato. She does note that Metro has enhanced the signage, for instance to feature a train’s number of cars, alongside the line color, destination, and number of minutes the train is expected to arrive.

Every Monday, the ‘Huh?’ Bub takes your questions. Got one?