[tedmiston]

> The platforms are fairly narrow and have no railings, and they aren't designed to hold two full train loads of people at the same time.

It seems pretty unlikely that 100% of the people on the outbound train would use the app and trust the historical data to go to the platform early.

[potatolicious]

It doesn't have to be 100% - a significant number of waiting people will still present a safety issue.

The platforms are very narrow for the LIRR tracks, so holding 200% of a train (outbound and inbound) would be sheer pandemonium, and would practically guarantee someone falls off the platform. Even holding 100% of a train (just inbound, disembarking passengers) is already straining the platforms and methods of egress to their limits.

Holding even just 110-120% of a train load is very much a safety issue. I'm with the MTA on this one - the "mad dash" is horrifyingly inefficient, but is the safest course of action.

Of course, the correct fix to this is to fix the platforms such that passengers can wait at track-level without safety issue. But, of course, that's a multi-billion dollar problem nobody seems willing to touch.

[greglindahl]

People in that station actually talk to each other, so a few % of app users in the crowd might result in a large number of people knowing.

I'd hate to imagine what would happen during peak if a train came in on an unexpected track AND a different train on the expected track - it is not unusual for multiple trains to be announced at once. Then you'd have a pile of people trying to go up those narrow stairs while a pile of people were trying to go down.

[futurix]

Once people see others walking towards a platform (particularly if they just checked something on their phones), they tend to do the same.

[dkrich]

But there are lots of trains leaving at any given time going to different places. There's no way to know which train somebody is heading to without asking them.

[futurix]

There aren't that many leaving simultaneously - plus they tend to be slotted into the same group of platforms.

[dkrich]

Yes there are. That's the whole problem. It's complete chaos. There are several hundred people huddled in one area looking at one giant screen and there are several trains being called in sequence. How would you know that a given person was waiting for the 4:30pm Acela to Union Station to be called and not the 4:33pm Northeast Regional to Boston?

As somebody who commuted for a long time at peak rush hour back and forth from Penn Station to D.C., I can tell you that following people who "seem to know where they're going" would not be a reliable strategy.

[ori_b]

There are dozens of platforms going to different places. Picking a random stranger and following them isn't going to get you where you're going.