For those interested in such things, here are four different cuts of the Office of Road and Rail 2021/22 passenger travel data projected onto a shortest-path network using the centre-line track-model.
These represent the passenger journey numbers either in a colour scale white-to-orange, scaled line width, or both.
The travel data was kindly provided by Alasdair Rae with the centre-line track-model by Peter Hicks through #OpenRailData.