High speed rail is much more expensive to maintain than ordinary rail. Motorways are also more expensive to maintain than normal roads, but I think the railway has more capacity than both.

The comparison for a freight railway vs. an equivalent road is obvious: private companies who need the entire capacity, like mines, build railways.

(I will leave it to someone else to find figures for high speed rail vs. an equivalent motorway.)

Do you have a source? I'd expect rail to be more expensive from a capital expenditure perspective (laying rail, ties, buying cars, etc) but much cheaper to operate (coefficient of friction is lower between train wheels and rails than with rubber tires and roads, optimal speeding and slowing causing less wear on tracks, less downtime as rail repairs are much simpler than road repairs, etc)

In the UK, Network Rail spends about £150k per track kilometer per year on maintenance and renewal. Track needs constant maintenance through ballast redistribution and compaction to maintain track geometry; the rail itself needs to be ground regularly to maintain its shape; points systems need to be maintained, as well as signaling systems, earthworks and embankments, even vegetation.

Maintenance costs for major roads in the UK (trunk motorways and A roads) is something about half that.

All Network Rail railways: £4479M / 20,000 miles of track = £140000/km

Strategic Road Network: £700M / 4,436 miles = £98000/km

Not included: cost of pollution, injuries and deaths on the roads.

Not considered: potential and actual capacity of the roads vs the railways, potential for historic underinvestment meaning higher current costs, whether these statistics mean a single track/road lane or all the tracks/lanes, usage costs for passengers and freight.

A breakdown of the railways costs would be useful for a better comparison, i.e. major lines only.

https://www.networkrail.co.uk/wp-content/uploads/2021/07/Ann...

https://assets.publishing.service.gov.uk/government/uploads/...

You need to divide maintenance by the actual usage of the infrastructure. Railway can handle much larger usage of the infrastructure per km than a motorway can. You may need 4 motorway lanes to support the usage of a single train track in order to handle the same capacity. Per capita, rail costs tend to be a lot lower as rail can handle much more than 2x motorway throughput.

You need to factor in the cost of moving goods for each.

I really don't, if my point is to rebut the statement "the whole point of trains is that expenses are largely one-off."

I love trains. I used them all the time when I lived in the U.K. and in Japan. I've ridden Amtrak from New York to San Francisco, and the Orient Express. They are, however, very much not a one-and-done investment as is being suggested elsewhere in this thread.

People are largely familiar with road maintenance, but most of them have no idea at all about maintenance of the railway.