I have the ideal road plan for Britain. Take the 16 major highway schemes worth £15bn and bin them

But does it fix anything? Conventional economic thinking is that roads are the lifeblood of the economy, essential for boosting efficiency. Yet the evidence of 100 years of transport policy based on this notion is that road building is a pointless, Sisyphean task. A generation ago, a report by an obscure government committee, Sactra (Standing Advisory Committee on Trunk Road Assessment), found that adding capacity to the road network simply encourages more people to jump into their cars, thereby quickly filling up the new lanes and ensuring that congestion is in no time as bad as before.