There appears to possibly be a very good reason for this short notice change at Cambridge, there are no services between Kings Lynn and Ely, the 1638 should have come from KLN but instead started at CBG formed from at train that terminated at CBG that should have gone to KLN, this train is shown as arriving at CBG at 1630.5 in platform 1.
Yes, I'm aware, I was right there, trying to catch that train to Ely and was more than a little irritated that I was going to have to hang around in the cold for another half-an-hour on Cambridge station! (Particularly as there was an a semi-fast train at 1643 going south, I don't see why the fast service couldn't have continued to Ely and turned there, but I digress...)
Looking at RTT, they'd already done the same for the 1538 and then continued to do so for the rest of the day. Seems it would have been easier if the train had been put into 8, if possible, or if not, the change announced somewhat earlier.
That said, there will be cases like this where a platform change legitimately needs to be announced at the last minute. I think there ought to be some sort of standardised announcement along the lines of 'the train won't be departing for another 10 minutes, please don't rush, if you need to use the lift you've still got plenty of time', etc. Hopefully that would help avoid the sort of scenes I saw at Cambridge yesterday.
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I read this and immediately decided that I had to reply and suggest Cambridge, from platform 7 or 8, to any of platforms 1, 2 or 3.
I maintain it should have been required to add a bridge or underpass at the south end of Cambridge, as well as the one added at the north, when building 7 and 8. Given how frequently platform alterations happen at CBG, often at the last minute, the current setup isn't remotely adequate.
The addition of the stupid illuminated advertising screen on platform 4 and the new immensely ugly barrier opposite the entrance, both narrowing the platforms, isn't helpful either.