The London Assembly transport commitee's dramatic intervention last week looked set to reignite the congestion charging debate.
Congestion has been rising again on the streets of the capital, fuelled by increasing numbers of delivery vans and private hire vehicles, and reallocation of road space for bus services, cycling and walking.
The flat rate congestion charge is too blunt an instrument, the committee says. It calls on the London mayor to reform the charge to reflect more closely when and where congestion occurs, and calls on him to begin planning in the long term to introduce a citywide road pricing scheme.
Congestion is certainly a cause for concern. Rising bus patronage, one of London's big successes of recent years, has gone into reverse in the face of slower bus journeys.
In addition to its comments on road pricing, the committee makes a number of other strong suggestions for tackling the problem.
Outside London, of course, congestion charging has been seen as politically off -limits since referendums in Edinburgh and Manchester rejected charging proposals.
In London, where Ken Livingstone consulted but then acted boldly to introduce the charge in the face of opposition, the charge has been accepted. Indeed, a survey by the transport committee indicates that 50% of road users would back road pricing with only a fifth against, and 63% would switch to driving at less congested times of the day if the charge reflected this.
The response from the mayor's office has been lukewarm, however. The committee has asked for a formal response, but the signs are that Sadiq Khan believes TfL is doing enough to combat congestion and has little appetite for reopening the question.
There are other signs congestion is rising up the agenda, though. In the TT Bus Supplement this month, Go-Ahead managing director for bus development Martin Dean argues that support could be gained for differential pricing, made possible by new technology, perhaps if revenue were recycled back into transport to avoid accusations of a stealth tax. In this issue, Jim Steer identifies the challenge of managing growth in freight traffic without harming productivity. And last week, 50 potential entrants met for a briefing on the Wolfson Economics Prize, which is seeking proposals for a reformed system for paying for roads.
Few politicians, though, want to do anything to alienate motorists. It may be that the National Infrastructure Commission was on the right lines when it asked for views, in last autumn's call for evidence for its national infrastructure assessment, on what opportunities the advent of mobility as a service creates for road user charging. It is possible that user charging will remain politically impossible until mobility as a service, in which users pay a single subscription for travel in all its forms, becomes widespread.
What, then, about another possible solution – driverless cars? One of the main arguments put forward by advocates of autonomous and connected vehicles is that when cars are able to communicate with each other and regulate their own speed, they will be able to travel safely
closer together at high speeds, smoothing traffic flow and unlocking extra capacity on the road system. Atkins has put this to the test in a microsimulation modelling exercise for the DfT.
On motorways and A-roads the results are disappointing. Autonomous vehicles, the study predicts, will not have a significant effect on reducing journey times and delays until somewhere between 50% and 75% of the fleet is capable of at least some autonomous behaviour.
In urban areas the story is different. The simulation suggests delays could be reduced by 21% in congested towns with only a quarter of the fleet having some degree of autonomy.
On the face of it this could be a breakthrough. Should the Government, the automotive industry, and anyone with an interest in transport be doing all they can to speed up the development and introduction of AVs?
Unfortunately there is a snag. When truly driverless cars become available, it is likely there will be a considerable "induced demand" effect. If your car will take you seamlessly from your home to your dental appointment, say, why would you bother to wait for a bus? Presumably you won't even need to have a driving licence.
This effect was outside the remit of the DfT study, but it seems that it is at least possible that AVs could exacerbate congestion rather than reduce it. In which case road pricing will be even more necessary, not less.
Reference: Transport Times January/February Issue
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