Since the £4.6bn cost is complete garbage, as it's based on an invalid calculation that integrates a non-integrable quantity, the £3000 per household is also garbage.
You can't proceed rationally from a completely irrational number.
Since the £4.6bn cost is complete garbage, as it's based on an invalid calculation that integrates a non-integrable quantity, the £3000 per household is also garbage.
No, because:lpm wrote: ↑Wed Dec 06, 2023 2:23 pmBut the motorists and the third parties are almost the same people.Sciolus wrote: ↑Wed Dec 06, 2023 12:35 pmPeople are talking about imposing costs on motorists in order to provide benefits to third parties. In fact, we are redistributing a fraction of the costs that motorists impose on third parties back onto the motorists. That seems rather harder to argue against (without going "waaaah, road tax!!11!").
the people who live on roads that are both heavily-trafficked and have dense houses along them are considerably poorer than average and drive less than average. There is a strong social equity issue behind this policy.
Cough.lpm wrote: ↑Wed Dec 06, 2023 4:42 pmIvan, you started off the thread by pondering the safety saving - £110m p.a. cost vs safety saving being some portion of £400m. You forgot the non safety benefits.
You've now forgotten the safety saving and are effectively only comparing the £110m to increased enjoyment of homes.
You know you can't do this. List all the benefits and guess at a £ value for each, then compare the total to £110m p.a. (or whatever) cost.
I think you are right, although the analysis mustn't be totally damned. It should give us an idea of what this is costing us, and then we can say, so this stuff I believe in, can it really be worth the gap? And the gap should be not to break-even, but to remember that public money is in short supply and public money should to better than break-even.El Pollo Diablo wrote: ↑Thu Dec 07, 2023 11:14 amI think further to that, this may be a good case of the strategic case for the reduction being somewhat at odds with the economic case. The strategy is, "let's make roads safer so fewer people are killed or injured and communities can work better", in a nutshell. The economic case says, "yeah, but the total sum of the tiny cost to a lot of people is, by our calculations, greater than the monetisable benefits", if you follow the DfT's transport appraisal guidance and HMT's Green Book principles.
Without wishing to divert too much, HS2 has similar issues. The strategic purpose of the line (increasing capacity, allowing more bums on seats and freeing up the normal railway to run different services; in turn, driving wider economic investment in non-London cities such as we're currently seeing in Birmingham) isn't very well captured in the economic case, which largely focuses instead on the benefits of faster journeys. The level 2 and 3 wider economic impacts are poorly modelled, despite them being the point. And, much as it pains me to admit it, sometimes there needs to be a step of faith that something is the right thing to do, and the analysis be damned. But then, that leaves the door open to Boris Island and tunnels under the Irish Sea.
There have been increasing efforts recently to try to move away from the economic case being the be-all-and-end-all and towards the strategic case taking precedence. That would be good to see, but all the efforts come up against the big hulking monolith that is the Treasury, where investment goes to die.
For some interesting thoughts on the justification for the M50 - https://www.pathetic.org.uk/current/m50/IvanV wrote: ↑Thu Dec 07, 2023 12:37 pmA classic case was the introduction of motorways to Great Britain. The Treasury was against it, the economic case didn't stack up. But it was no white elephant, even remembering what it had cost. The M50 (Tewkesbury to Ross-on-Wye), we can see that is a white elephant.
It's a simple story. It's well known that original purpose of the M50 was to connect the Midlands to South Wales. It started construction before the M5/M4 route via Bristol and the Severn Bridge was complete. But as soon as it was, it became apparent the M50 was unnecessary, so they didn't finish it. Which they really should have realised in the first place.Gfamily wrote: ↑Thu Dec 07, 2023 12:55 pmFor some interesting thoughts on the justification for the M50 - https://www.pathetic.org.uk/current/m50/IvanV wrote: ↑Thu Dec 07, 2023 12:37 pmA classic case was the introduction of motorways to Great Britain. The Treasury was against it, the economic case didn't stack up. But it was no white elephant, even remembering what it had cost. The M50 (Tewkesbury to Ross-on-Wye), we can see that is a white elephant.
Some of the comments are interesting too
I think it shows the limitations of technocracy and the need for politicians (yes, it hurts me to say that). It's hard to capture the various impacts of a proposed measure, and very hard to compare incomparable impacts. We can try to monetise them so they can be compared, but that is highly uncertain (we haven't gone into the problems with Willingness To Pay, for instance), so ultimately we need an informed but subjective appraisal that considers how a measure fits into the totality of policy.Woodchopper wrote: ↑Thu Dec 07, 2023 9:44 amThanks all for the discussion.
As a meta comment the thread seems to be a good example of the practical difficulties in implementing utilitarianism. While it may be an attractive principle, as this thread shows it quickly becomes very difficult to a) identify and reach a consensus on all the relevant consequences of an action, and b) to be able to compare those consequences with precision.
In theory the consequences of speed limit reduction should be an easier problem, as we can measure things like death and injury or average journey times. Other pressing social problems are much more difficult.