The Tube - episode 3

[Iain]

Just to be awkward(!) I'm now starting to think maybe Stevo's idea is better. My previous post is perhaps mathematically more sensible (it's a bit like rounding numbers to zero decimal places - so 1.5 minutes is rounded up to 2) but if I was waiting for the train I'm not certain I'd view it the same way.

One of our trains during the all lines run said "1 minute" on the DMI. We didn't mentally note the precise time on the clock but it was 11:37 and some seconds, and the train didn't pull in until 11:40 and 20 plus seconds, so at least 2 minutes 21 seconds from when we arrived on the platform

[geofftech]

...

[tubeguru]

If we assume that at the moment the display changes to "2 min" then the train will arrive in exactly two minutes (I know - a HUGE assumption), then when it changes to "1 min", the train should be here in one minute.

By logical extension of this, we can take it that when the train is one minute and 30 seconds away the display will still be showing "2 min".

So:

Display shows "5 min" - train is between four and five minutes away
Display shows "4 min" - train is between three and four minutes away
Display shows "3 min" - train is between two and three minutes away
Display shows "2 min" - train is between one and two minutes away
Display shows "1 min" - train is no more than one minute away
Display shows "0 min" - train SHOULD be here.

To be fair to the system, trains do usually arrive within 15 or so seconds of the display changing to "0 min".

That's how I see it.