Park Lane is an essential part of London's road network, so getting rid of it would be foolish. But what about burying it? It would restore the easy link between Mayfair and Hyde Park, dramatically improve the public environment on one of London's most famous roads, and release 6.5 hectares of land. Floorspace there sells for about £2,000 per sqft (and sometimes more, see zoopla.co.uk/for-sale/detail…), so if we achieved a net floor-area ratio of 8, implying buildings of 16 storeys or so, after putting aside land for a bus and cycle lane, access streets, plus staircases and amenities, we could generate gross: £20,000 (price per square metre of floorspace) * 6.5 (hectares) * 10,000 (square metres per hectare) * 8 (net FAR) = £10 billion. After build costs for the buildings that would be more like £7.5 billion. So the upside is £7.5 billion, or so. How much would it cost to cut and cover that strip of land? The Hindhead Tunnel, the UK's longest non-estuarial road tunnel, was completed in 2011 at a cost of about £50 million per lane-km in today's money: the most expensive road tunnel ever in the UK. It was bored, rather than cut and cover, which usually makes things more expensive, but let's assume conservatively that this is the cost. £50 (million per lane-km) * 6 (lanes) * 1.3 (kilometres) = £390 million. So our scheme nets out at about £7 billion of profit. Let's say £6 billion, just in case reinforcing the road's roof costs more than we think, or to make sure there is passive provision for railway rights of way we might want to put in the space of the tunnel Of course, it's not that simple. If you are a Londoner or tourist and you don't drive through London, and you don't own a property currently fronting Hyde Park, then this scheme is a pure benefit for you. But drivers lose out temporarily, during construction, and Park Lane hotel owners lose out permanently. Park Lane itself gets much nicer (less noise, pollution, and traffic), but the prestige of the address falls, and in some properties the views and light might get worse. How to fix this? I suggest that to pull off this scheme you would give a substantial portion of the benefit to the owners of the properties immediately fronting Hyde Park, on Park Lane. What I would do is a sort of bespoke land readjustment. I would create a special purpose vehicle company, of whose shares some minority share were owned by the Mayor of London and Westminster Council, and another share were given to the owners of Park Lane properties, in proportion to their value. I would grant planning permission to pull off this development, probably by special development order (cps.org.uk/wp-content/upload…), subject to some charge, on the condition that two thirds of the owners of Park Lane properties voted for it to go ahead. I think the large financial benefit would make the owners see sense (but I don't think they will lose anything remotely like £6 billion in total, so I don't think we need to give them all the value). Park Lane is a special case, because it's such a no brainer, but if we did generate expertise at burying roads, then London is scarred by some very nasty at-grade motorways. I grew up on the A3 and it really should be underground between Tolworth and Putney/Wandsworth. I live right by the A2 now and I think similarly for certain sections. There are many other cases. If we could get costs down to £10 or 20 million per lane kilometre then we could really go gangbusters.