^ the number of passengers aboard the IEP▸ Train on approach to each station;
^ the number of passengers aboard the IEP Train on departure from each station.
One hopes that the number departing from from one station is equal to the number approaching the next (arrival of early babies excepted!).
The mind boggles a bit with the thoughts of what this sort of data can do, especially when linked to ticketing:
"There are plenty of seats in First Class. If anyone would like to upgrade ..."
"Stop the train. We're the
BTP▸ . There's someone on board who hasn't bought a ticket"
"As this is a quiet train, it will be designated off peak and you'll be refunded the difference in fares"
"To relieve overcrowding, we'll be attaching an extra carriage at Reading"
"We are sorry this train has been delayed by swans on the line near Maidenhead, and we notice there are passengers for Yeovil on board. A Taxi has been arranged for you three at Castle Cary as the last connection has been missed"