What we *don't* know is what that future demand will look like. Pre - Covid there were well established trends which could be used to predict. That's not the case currently.
Whilst we don't know (and we never can), there's a number is reasons to encourage a switch from air and road based travel to rail
Here we go again - another anti car rant. The problem will always be rail lacks the flexibility most people require - it's no good for your local shopping trip, it's no good for most holidays. Get over it, the car isn't going away no matter how much you shout and stamp your feet.
Cars will almost always have a part to play in our travel mix, however it is not anti car to say that too much travel is currently undertaken by car when other nodes of travel could well be better.
Given that cars have high up front costs, a significant reduction in the number of regulator trips by car (such as driving to/from work every day to a few times a week) could actually make it more likely that some could increase their rail use (this isn't likely to happen quickly as it's likely to be something younger couples would be likely to do over those who have had two cars for years).
For every trip which is undertaken by foot, by bike, by bus and by train then it reduces the number of trips by car. Given the limited road space that we have, that can only be a good thing. Unless we undertake a significant programme of road building in some of our most congested urban areas (and the upheaval and cost that would require), then we are stuck with needing to fund public transport and bringing in measures which could be seen as anti car.
However if you want to drive on roads which are not full of traffic then you want to encourage an many other people as possible not to drive. That's likely to come at a cost to you, however that cost does produce benefits.
As an example, the congestion charge in London (when first introduced) meant that rather than stop start traffic through very Central London, that it was actually quite nice driving. Yes there was a cost, but for business that charge was offset by staff being more productive as they spent a lot less time in traffic.
For the local population it meant that there were fewer cars than would have otherwise been the case, giving them better air quality.
Actual one of the best ways to reduce car ownership is the use of car clubs, as typically each one reduces the number of cars owned in the local area by about 18. Given that cars parked on carriageway reduces capacity of the road network, then this is certainly to be encourage.
Even if it doesn't increase road carrying capacity, the fact that it would increase the ability to park when going and visiting others is likely to be of significant benefit to many.
Yes cars are here to stay, however their use should be reduced (at least a little) from what we currently do. The problem is to get that to happen the most efficient way to do so is to add a cost, be that a monitory cost or a time cost.
Such methods are labelled as anti car, however those costs being added are tiny compared with the costs which would need to be added even to reduce car use by 20% let alone wipe out entirely car use.
Given that 85% of people live in an urban area (a settlement with over 10,000 people in) the fact that over 80% of all travel is by car shows that there's a lot of urban travel which could fairly easily be reduced a little without impacting the number of people having access to a car. Certainly long before we need to be forcing the elderly and disabled out of their cars and a fair amount of time before we need to consider impacting on those who live in rural areas.
If you reduce rail fares you might recover demand but will doubtless exacerbate the financial problems the railways have. There is a financial hole which needs to be addressed so growing the network and expanding services will only happen where their business case shows they aren't making that financial hole bigger. Again you and others won't like this, will shout and scream that it's unfair, biased against rail etc, etc - but the facts don't change even if you don't like them.
As others have highlighted income may increase. However the other thing to note the cost of running HS2 services are likely to be cheaper than other long distance rail services.
Lease costs of the trains typically account for about 1/3 of all TOC costs, yet HS2 because of its speed is likely to need comparable numbers of coaches to the existing services, even though there'll be 16 coaches per train compared with 9 or 11.
Taking Manchester as an example it currently requires 1 unit every 5 hours before it can run the next service, with 3tph and 9 coaches per train that requires 135 coaches, however there's at least some 11 coach units, so the upper limit is 165.
However compare this with HS2 which will likely require 1 unit every 3 hours, with 3tph and 16 coaches per train this requires 144 coaches which means that if 1/3 of the existing services are 11 coaches long then the number of coaches needed (145) is almost identical.
However one of the suggestions for increasing capacity without building HS2 is lengthening to 12 coaches, if we do that then the maximum number of coaches needed rises to 180. As such the cost to the TOC of running services without HS2 could start to increase significantly. Whilst it's unlikely to be by enough to pay for the building of HS2, the extra capacity provided could allow more to travel which could do.
However that's only one TOC cost, another large cost is staffing (again about 1/3 of costs), well with drivers being able to run more services within a shift that cost also reduces. As rather than needing 10 hours of staff time to run 2 complete services (i.e. London, Manchester, London, Manchester, London) you could run 3 complete services in 9 hours of staff time (i.e. London, Manchester, London, Manchester, London, Manchester, London).
Yes there'll be a need for more energy costs, however these terms to be quite a small cost overall as they come within the remaining 1/3 of costs which includes several other costs including headquarter costs, ticket sales costs, etc.
Even at 12 coaches you'd only manage about 660 seats per train, HS2 is targeting 1,100 seats per train. If you fill them to the same percentage capacity then your HS2 ticket prices could be on average 60% of the price of the existing services, but with the extra passengers being in the same income. However having detailed above that the costs would be at least slightly lower, the overall "profit" would still be higher.
