On 12 September 2006 the Department for Transport initiated an experiment on the M42 in which, in periods of congestion, drivers would be allowed to use the hard shoulder. Media coverage of the experiment focused on safety problems: in the event of breakdowns or accidents emergency services would take longer to get to the scene.
There was virtually no discussion of the policy incoherence that under-pinned the experiment. The Department for Transport has two policies for dealing with congestion. The oldest is predict and provideĀ, i.e. the provision of more road capacity to accommodate forecast traffic. Traffic growth has rendered the prediction part of this policy redundant. The Department now struggles to provide capacity to carry existing levels of traffic. The M42 trial is a cheap application of this policy. The second, newer, policy is congestion charging.
Both policies are doomed to failure because neither addresses the underlying problem of which congestion is merely a symptom: the continued rapid growth of the nations car population. Providing more road capacity at the hottest congestion hot-spots merely releases suppressed demand and increases the temperature of surrounding warm-spots. And so long as growth continues throughout the system, trying to price traffic out of the hot-spots will also spread the problem.
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