It’s not about congestion, but damage to the roads.
Even assuming damage to the roads is entirely caused by lorries, which it's not, and that all traffic lost from rail was lost to the road, which it wouldn't be (cement and stone is probably amenable to water transport).
This would increase road freight mileage by ~12%.
As almost all rail replacement mileage would be on the Strategic Road RN, which carries roughly half of all road freight mileage, we would be looking at a 24% increase in it's budget.
The SRN costs about £1.1bn a year, so we would be looking at something £250m a year extra.
Direct subsidies to rail freight run about £18-20m per annum.
So about £2
30m per year cost to the SRN net direct freight support.
But given that support to Network Rail is about £4,200m each year.......
It doesn't seem unlikely that net support would be lower.
I made a tongue in cheek suggestion in a speculative thread once upon a time that whenever somebody suggests railways should be electrified at 750v DC third rail as an alternative to 25kv AC, we should come round their house and re-wire it from 240v AC to 12v DC. They will be required to use low powered appliances that connect into car cigar lighter sockets, until such time as they reach enlightenment as to the benefits of a industry standard electrification at a useful voltage
If you can provide evidence that a third of the houses with electricity in the UK are so wired, then it would be a justifiable comparison.
The same argument would imply that 25kV was a worthless pile of junk next to the awesome power of 50kV.
Also 750Vdc
is an industry standard electrification voltage, and it is pretty definitely useful given how much work it puts in every day.
And yes, I am a terrible pedant.
