Comparing the UK Department for Transport forecasts of road traffic with actual road traffic (via George Monbiot). Interestingly, it repeats the same systematic error the US Department of Transportation has been making for years.
The full story is here:
Since the 1980s, the Department for Transport has consistently forecast traffic growth along a steep trajectory. But the distance covered by car drivers in England is now 7% lower than it was in 1997. The total volume of traffic has flatlined since 2002, nixing every prediction the department has made. Last year, 32 transport professors wrote to the secretary of state pointing out that, in the absence of traffic growth, "the basis for major infrastructure spending decisions appears to be changing".The only thing likely to induce more traffic growth, they argued, is building more trunk roads, and that would put intolerable pressure on the city streets into which they feed. The facts might have changed, but the policy remains the same. The department continues to make the same failed forecasts, using the same failed model. The desire to build – and to appease the construction industry and motoring lobby – comes first, and the forecasts are made to fit.
[image credit: Better Transport]