Capacity is the issue - if anyone is interested, I can really recommend How the railways will fix the future by Gareth Dennis.
The railways have 3 main jobs: freight, intercity services & local rail. They are the best way of transporting stuff (from a public policy perspective not from a personal choice) because they are safe, speedy & efficient but we don’t have the network / capacity to do this effectively in lots of the country, which means we don’t have enough freight on the railways in some places (so we have more lorries and more potholes), we don’t have the intercity services we need in some places (eg cross-pennine routes) & we also don’t have the local services in others. We also don’t have enough underground / metro type light rail or enough trams.
What really surprised me from the Dennis book is that the lack of capacity makes the railway more expensive to run. The other thing that really shocked me is how little progress we have made on electrication even though we’ve been doing it for years.
From a transport policy perspective, this just doesn’t make sense. No-one likes congestion, and rail is capable of getting people out of cars as if you can swap a car journey for a rail journey, there’s a good chance that the rail one will be quicker. It’s better for air pollution / CO2 targets and rail is much, much safer than the road. Buses have their place, but we’re using them to substitute for rail, which just doesn’t work as they are too slow and can’t carry as many passengers.
Where there are new / reinstated railway lines like the Elizabeth Line or the Northumberland Line these seem to be really popular - I’ve no idea why politicians & business leaders aren’t demanding more rail.
HS2 has been a massive disappointment- but part of the reason for it was to tackle the lack of capacity on the west coast mainline and that problem is still there & still needs to be solved.
I agree though that we could do without more motorways as there has been evidence for years that they don’t solve congestion, as the extra capacity just means that more people drive so the congestion persists.