*sigh*
It's basically one man, obsessive and bus nerd Paul Withrington.
He's somebody that is incapable of reasoned debate and has been trying to shut down the railways for over 40 years, pretty much single-handedly. Most of his ideas are taken from the railway conversion league, a group of eccentrics made up of less than 10 people, and actually got BR and the DFT to make a study for them. It was concluded that the idea was flawed. They disbanded years ago, but the bus fantasies live on with some people (well one actually) who think it's a wonderfully good idea that will save so much money supported by dodgy analysis, the savings are almost entirely illusionary, and the service would be significantly slower and would never support a major city in it's transport needs. Which is why places like Dubai, who relied on buses for years, ended up putting in rail because of the gridlock.
Of course they haven't completely given up, which is why we have the St Ives - Cambridge busway, £160 million for no time savings (over current bus timetables) and considered an expensive waste of money by all but a few people.
There's a number of logical errors:
1) Buses have the same passenger KM as rail, yet they have potentially 26 times more right of way. If they were so good they'd have more far more. We don't need to shut down the railways where there a plenty of roads that can be used, like the hard shoulder of motorways. Because this has never been done with the modal shift, proves the whole concept is flawed. To any normal person the suggestion bus lanes on standard roads would suffice, and indeed these are put in. London has some 330 miles of them.
2) They are slow and unattractive, most people would take to their cars. The entire geography of the SE would be changed, and towns like Peterborough, Brighton etc no longer commuterable. Many commuter towns would lose significant income, and house prices driven down.
3) They effectively get a free ride. They get tax refunds on road take. If they had to pay their own right of way, charges would be considerably higher, beyond rail.
4) In practice they are nothing like as environmentally significant as he says. Coaches are commercial because they use pre-book yield management and only run on specific flows. A fairer comparison is buses and coaches, and the combined Co2 pass KM is a lot more than rail. Indeed, coaches are only the same as intercity trains anyway.
5) Flow is nothing like he sates: Bus lane capacity is around 6,000 people per hour max on road, without grade separation. Hardly any of the rail network is grade separated. But rail can achieve 40,000pph (eg jubilee line) or 100,000 pph in the case of Hong Kong. What limits it is 1) demand 2) population density. He doesn't take into account dwell times, junction crossing, and so on. The mathematics is well understood, and it can all be simulated. Indeed, you cannot put more people through many rail stations because there simply isn't the passenger space.
6) The cost: You'd have to write off all costs, £20 billion worth of NR, £20 billion odd leasing companies and legal costs. You'd never get most of it through planning. Then, conversion is between £10 and £100 million a mile, with 10,000 miles I make the total cost nearly £250 billion plus £50 billion railway costs. I'd like to see a bus company pay for that! All this for a much slower, and less attractive journey. You cannot open the space to cars, because typical on road capacity is about the same as one commuter train per hour.
7) No public support
8 ) You'd make 150,000 people directly employed in the railways redundant and 500,000 in directly. The economic folly he doesn't state or include is tax paid on wages, industrial tax, etc. More to the point none of the huge external costs (calculated to be some £40 billion) are included for road. Anyway, the money spent on rail doesn't disappear into the etha, its gets put back into the economy through spending and employment, and external benefits of providing trains: Less pollution, congestion, social inclusion, agglomeration, time savings and so on.
9) It's not cheaper per person anyway, bus fares can be quite a lot higher than rail, they certainly are here. They have 50% of their cost, overall subsidised, like rail in any case. Cars cost typically 50-60p per mile to run, and are only cheaper loaded with 3 people. The road access charges are typically 15 times higher than rail. But that doesn't mean it's profit with the costs to the environment, health, and so on.
10) Disruption: 80% of people arrive in Central London every morning by rail, and significant amounts in other major cities. The modal share on some rail routes is 30-70% v road. What are you going to do? Shut London down. London without rail would be in perpetual gridlock and not be very attractive to business and the jobs it creates.
The man is a right wing idiot frankly, and there is so much spin and bluster on his site it's not worth any consideration to anyone that known anything about the subject. He's been objecting to rail schemes for over 30 years, and cost the taxpayer a lot of money in the process.
I know people who have met him and they state he's obsessed with the subject beyond normality.