Costs of ALR versus widening: evidence from the M25

[jackal]

As this old chestnut has reappeared I took a look at the Post Opening Project Evaluations (One Year After) for M25 schemes completed in 2012-2015. The POPEs provide an outtrun investment (i.e., construction) cost. Mostly they are in 2002 prices though unfortunately J5-7 is in 2010 prices (so is inflated compared to the others):

J5-7 ALR, open 2014, £113.7m/11 miles = £10.3m per mile
J16-23 full HS, open 2012, £460m/22 miles = £20.9m per mile
J23-27 ALR, open 2015, £101m/17 miles = £5.9m per mile
J27-30 discontinuous HS, open 2012, 272.4m/17 miles = £16m per mile

Maintenance costs over 60 years are also provided (again, J5-7 is in 2010 prices, the others 2002). Widening schemes actually reduce maintenance costs compared to the status quo ante, hence the negative numbers:

J5-7 ALR, £20.9m
J16-23 full HS, -£15.4m
J23-27 ALR, £22.8m
J27-30 discontinuous HS, -£23.9m

So in short, widening was about 3 times as expensive as ALR to construct. It has lower maintenance costs, though this is a minor part of overall costs.

https://assets.publishing.service.gov.u ... n_2020.pdf
https://assets.publishing.service.gov.u ... _Final.pdf
https://assets.publishing.service.gov.u ... n_2020.pdf
https://assets.publishing.service.gov.u ... _Final.pdf

[WHBM]

It would be good to see the full widening costs actually broken down.

- Additional public enquiry costs.
- Land purchase, amount paid plus all the legal work.
- Additional civils costs.

You also have to consider the public reaction. If the public don't like it and, through their politicians etc don't accept it, what's the point ? There's no greater example at the moment than the football story. Made sense on someone's spreadsheet.

[Bryn666]

The problem with accountant led engineering is the end result is often not satisfactory for the actual user.

I have argued for a long time that the DfT WebTAG system does not factor in any of the unquantifiable aspects of a road or cycleway scheme, and as a result there is a bias towards maintenance of the status quo. This will be interesting when the government have just announced they are making even tighter carbon targets which are completely incompatible with the current planning system that is geared entirely around mass private car ownership in suburbs.

Pay peanuts, get monkeys.

[wrinkly]

This will be interesting when the government have just announced they are making even tighter carbon targets which are completely incompatible with the current planning system that is geared entirely around mass private car ownership in suburbs.

They're making targets but not making policies to achieve the targets.

[Phil]

This will be interesting when the government have just announced they are making even tighter carbon targets which are completely incompatible with the current planning system that is geared entirely around mass

The Government believe that mass adoption of electric vehicles and better heating solutions / insulation will solve that - avoiding the need to become deeply unpopular with voters!

We might be in a climate emergency but the selfish nature of human beings shows no sign of ending - restrictions on mass motoring are simply not an option in a democracy.

[SteveA30]

The figures do show that SM was done over widening, because it is cheaper, which I still think was the main factor, rather than safety. Safety had to feature in the publicity of course. The disagreements over which actually is safer will never end though.....

[Vierwielen]

The problem with accountant led engineering is the end result is often not satisfactory for the actual user.

... snip

An accountant is somebody who knows the cost of everything, but the value of nothing.

[AndyB]

And an opposition politician is wedded to value and promptly has a fling with cost as soon as they're elected.

(Not entirely accurate, because plenty of opposition politicians whinge about how much money is being spent regardless of value to other people!)

The problem with accountant led engineering is the end result is often not satisfactory for the actual user.

I have argued for a long time that the DfT WebTAG system does not factor in any of the unquantifiable aspects of a road or cycleway scheme, and as a result there is a bias towards maintenance of the status quo. This will be interesting when the government have just announced they are making even tighter carbon targets which are completely incompatible with the current planning system that is geared entirely around mass private car ownership in suburbs.

Pay peanuts, get monkeys.

Are you sure we get something as useful as monkeys?

I'm not exactly convinced that the modelling adequately reflects the quantifiable aspects. How often do we hear "trains and trams are too expensive, have a bus instead" when the sum appears to be:

additional operating costs of more expensive system minus additional farebox receipts from a more popular system equals too much money required in PSO

instead of

additional operating costs of more expensive system minus additional farebox receipts plus money saved to the economy because there is more space on the road for people who can't avoid driving equals a potentially very different outcome.

Jackal makes a fair point about maintenance costs:

Maintenance costs over 60 years are also provided (again, J5-7 is in 2010 prices, the others 2002). Widening schemes actually reduce maintenance costs compared to the status quo ante, hence the negative numbers:

J5-7 ALR, £20.9m
J16-23 full HS, -£15.4m
J23-27 ALR, £22.8m
J27-30 discontinuous HS, -£23.9m

So in short, widening was about 3 times as expensive as ALR to construct. It has lower maintenance costs, though this is a minor part of overall costs.

However, I would predict that conventional widening schemes will in due course be provided with full smart technology, including CCTV coverage - it will be less important than where there is no hard shoulder, but MS4s, mandatory variable speed limits and speed/red X cameras will become the norm on all but the least busy motorways.