Cost estimates

Seeing the scale of the roads that were planned and the political turmoil that surrounded them is one thing. A different aspect of the Ringways plan, not often discussed, is what they'd cost. The sums involved are almost as unbelievable as the road plans themselves.

In 1972, the inspectors at the Greater London Development Plan Inquiry were very unhappy with the sketchy costings they had been given for the Greater London Council and Department of the Environment's vast urban motorway plans, and they demanded to know more. As a result, the GLC was forced to come up with detailed, itemised costings for the whole Ringways scheme, and from this we have an accurate picture of what it might have cost.

On this page you can see a slightly simplified version of the figures, and you can download a transcript of the full thing at the end. There's also an explanation of our methodology in using these figures to provide cost estimates for individual road schemes and equivalent prices in 2014.

Cost of GLC road schemes

This table lists the estimated cost of the sections of the Primary Network that were the responsibility of the Greater London Council, and a number of additional items (marked "extra") the GLC had not proposed but that the inquiry panel were considering recommending.

Route section Property Works Total
Ringway 1: Westway - Finchley Road £21,000,000 £58,000,000 £79,000,000
Ringway 1: Finchley Road - Dalston £25,000,000 £68,000,000 £93,000,000
Ringway 1: Dalston - Hackney Wick £17,000,000 £24,000,000 £41,000,000
Ringway 1: Kidbrooke - St Johns £7,000,000 £28,000,000 £35,000,000
Ringway 1: St Johns - Clapham £42,000,000 £94,000,000 £136,000,000
Ringway 1: Clapham - Chelsea Basin £4,000,000 £17,000,000 £21,000,000
Ringway 1: Chelsea Basin - Holland Park Avenue £23,000,000 £30,000,000 £53,000,000
Total for Ringway 1 £139,000,000 £319,000,000 £458,000,000
Ringway 2: A13 - Thamesmead £4,000,000 £34,000,000 £38,000,000
Ringway 2: Thamesmead - Falconwood £5,000,000 £22,000,000 £27,000,000
Ringway 2: Falconwood - Verdant Lane £4,000,000 £39,000,000 £43,000,000
Ringway 2: Verdant Lane - A23 £17,000,000 £63,000,000 £80,000,000
Ringway 2: A23 - A24 and M23 terminal £10,000,000 £16,000,000 £26,000,000
Ringway 2: A24 - Wandsworth £11,000,000 £6,000,000 £17,000,000
Ringway 2: Wandsworth - Beauchamp Terrace £7,000,000 £12,000,000 £19,000,000
Ringway 2: Beauchamp Terrace - Chiswick £5,000,000 £10,000,000 £15,000,000
Total for Ringway 2 £63,000,000 £242,000,000 £305,000,000
Clapham - Wandsworth Link £5,000,000 £17,000,000 £22,000,000
A40 to Ringway 1 (North Cross Route Link) £4,000,000 £19,000,000 £23,000,000
M1 extension to Ringway 1 £7,000,000 £17,000,000 £24,000,000
Ringway 1 Kidbrooke to Ringway 2 Mottingham Link £1,000,000 £10,000,000 £11,000,000
A20(M): Mottingham - Bexley boundary £2,000,000 £18,000,000 £20,000,000
M23: Ringway 2 to Ringway 1 £10,000,000 £30,000,000 £40,000,000
Total for radial routes £29,000,000 £111,000,000 £140,000,000
Dover Radial Route and link to Blackwall Tunnel £4,000,000 £19,000,000 £23,000,000
Parkway E: Ringway 1 to New Addington £12,000,000 £55,000,000 £67,000,000
Total for all GLC proposals above £247,000,000 £746,000,000 £993,000,000
Extra: deep bored tunnel at Blackheath -£3,000,000 £25,000,000 £22,000,000
Extra: cut-and-cover tunnel at Camberwell Grove £0 £1,000,000 £1,000,000
Extra: cut-and-cover tunnel at Ruskin Park £0 £2,500,000 £2,500,000
Extra: cut-and-cover tunnel at Wandsworth Road £0 £2,000,000 £2,000,000
Extra: cut-and-cover tunnel at Northampton Park £0 £2,500,000 £2,500,000
Extra: cut-and-cover tunnel at Chiswick £0 £2,500,000 £2,500,000
Extra: Chiswick Interchange £5,000,000 £20,000,000 £25,000,000
Extra: A3, A4, A13 and A40 works £1,000,000 £1,500,000 £2,500,000
Extra: A316 works £5,000,000 £10,000,000 £15,000,000
Total for all GLC proposals and extra items £255,000,000 £813,000,000 £1,068,000,000

Cost of DoE road schemes

This table again lists the costs of the Primary Network, this time showing schemes that would have been built by the Department of the Environment (previously the Ministry of Transport). There is then a summary of the total cost of both GLC and DoE schemes.

The costings for DoE schemes seem much more sketchy than for the GLC; in particular, not all of Ringway 3 had been designed in detail at this time, and it's more than a little suspicious that the route is broken into just two sections, both of which are listed as having three lanes each way. We know that some parts of Ringway 3 would have been wider than that, so it follows that some of these figures are only very broad preliminary estimates.

Route section Property Works Total
Ringway 2: M4 - M1 £7,500,000 £23,500,000 £31,000,000
Ringway 2: M1 - M11 £11,000,000 £43,500,000 £54,500,000
Ringway 2: M11 - A13 £5,000,000 £29,500,000 £34,500,000
Total for Ringway 2 £23,500,000 £96,500,000 £120,000,000
Ringway 3: North M4 - A13 £11,500,000 £90,500,000 £102,000,000
Ringway 3: South A2 - M4 £24,500,000 £99,000,000 £123,500,000
Total for Ringway 3 £36,000,000 £189,500,000 £225,500,000
A1 to M1 Link £0 £1,500,000 £1,500,000
M1 extension to Ringway 2 £6,500,000 £11,000,000 £17,500,000
M11: GLC boundary - A12 £2,000,000 £9,500,000 £11,500,000
M11: Ringway 2 - Ringway 1 £9,000,000 £41,000,000 £50,000,000
M12 £1,000,000 £14,000,000 £15,000,000
A127 £0 £500,000 £500,000
A13 £1,000,000 £4,000,000 £5,000,000
A20 £1,000,000 £10,500,000 £11,500,000
M23: Hooley - Mitcham £4,500,000 £17,000,000 £21,500,000
A3 £2,000,000 £7,000,000 £9,000,000
M4 and A4 £500,000 £4,500,000 £5,000,000
A40 £3,000,000 £27,500,000 £30,500,000
Total for radial routes £30,500,000 £148,000,000 £178,500,000
Total for all DoE proposals above £90,000,000 £434,000,000 £524,000,000
Total for all DoE and GLC proposals £345,000,000 £1,247,000,000 £1,592,000,000

The figures in these tables were based on 1970 prices, which is presumably the best baseline the accountants could use, but they were presented to the inquiry panel in 1972. In the early 1970s inflation was running at a rate scarcely believable today, and so the panel also requested that the totals be adjusted for March 1972 prices.

Property had gone up 30% in that time and construction costs 25%, so the passage of less than two years caused the total cost of £1.5bn above to have ballooned to more than £2bn in the final line of the ledger.

The full costings

The figures above are a simplified version of the full costings that were calculated and assembled for the GLDP Inquiry panel. 

If you prefer, you can download a transcript of the full document here and see the full detail.

Cost estimate methodology

Most of the individual road schemes described on these pages have a summary of the costs for land, housing reinstatement and construction works at the top of the page. Here is a brief explanation of how we reached those figures.


In most cases the extent of a single road, with its own page on, does not match the boundaries of the sections used to cost up the road proposals in this document. For example, Ringway 1's North Cross Route would have run from Willesden to Hackney Wick, but the costings include one entry for the section of Ringway 1 between Westway and Finchley Road, which spans parts of both the West and North Cross Routes.

In these cases it is impossible to know for certain how much of the cost would belong to each individual part if those sections were divided up. In the absence of information on which that sort of calculation could be made, costs have been broken down according to the relative lengths of the schemes. So, in the example above, the item "Ringway 1 Westway - Finchley Road" is about one third West Cross Route and two thirds North Cross Route, and we have divided up the costs on that basis.

It is always possible that the cost would, in reality, have broken down quite differently - that, perhaps, a shorter length would have incurred higher costs because it contained lengths of tunnel or complex interchange structures - but that level of detail is not available to us, so we have chosen to calculate costs based on what is known for certain, and that is the relative lengths of each scheme.

2014 equivalent prices

The costs above are all in 1970 prices. To put them into context for modern readers, the table of costs on each individual road scheme page includes an estimate of the equivalent cost in 2014.

The 2014 price has been arrived at by:

  • Adjusting the cost of land and property acquisition for inflation between 1970 and 2014 according to the Nationwide Building Society's property price index, using national data from 1970 to 1973 and then regional data for London when it becomes available from 1973 onwards. The simplified calculation for this is to divide the 1970 price by 231.5 and multiply by 9866.2.
  • Adjusting the cost of construction and other works for inflation. We have been unable to find a construction price index for infrastructure work that goes back before 1980, so the methodology is to assume the cost of construction rose in line with the highest "other" construction price index between 1970 and 1980, and then rose in line with the infrastructure construction price index from 1980 to 2014. Our simplified calculation is to divide the cost of works by 9 and multiply by 134.7.

By their very nature these calculations are very approximate and are not intended to give a precise or fully accurate cost for an equivalent road scheme in 2014. They are intended to illustrate the order of magnitude of the sums of money involved and provide the reader with a clearer idea of the scale of the undertaking of each proposed motorway scheme. For that reason we regret that we will not enter into correspondence about ways to improve or change the methodology for what is meant to be a very broad-brush illustration!

Cost estimates


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