There is both quantitative and anecdotal evidence to indicate that at certain locations road safety and congestion might be improved, with attendant economic and environmental benefits, by removing conventional junction control and introducing principles of shared space for particular periods of the day, or indeed as a permanent solution. Under the Traffic Management Act 2004, traffic managers should be able to ‘consider any possible action’ to improve the efficiency of their road network. Current Department for Transport advice on traffic management and street design reminds us that there is no statutory requirement for junction controls. Yet the absence of research into alternative methods of junction control means that options are restricted. A study by Colin Buchanan for the Greater London Authority in 2009 concluded that there are clearly, in general, time savings and hence an economic benefit to the use of traffic signal control but that there are periods of the day when greater benefit would be achieved by switching off traffic signals, and indeed there are likely to be numerous sites where signal control is not required at all. Hence there is a case for establishing trials to test the benefits of conventional controls against the potential benefits of uncontrolled, natural traffic flow, to provide evidence that could help improve the safety and efficiency of our urban and possibly rural road networks, and the wider public realm, and to achieve a more sustainable approach to traffic management. Across a number of junctions with, and then without, conventional traffic signal or priority control, these before-and-after trials enable us to monitor any changes to traffic demand and migration, congestion, vehicle and pedestrian journey time, and impact on buses, vulnerable road-user amenity, driver conduct, and the environment. The first such ground-breaking trial commenced in September 2009 at a complex and busy signal controlled junction in Portishead, near Bristol. This is already showing considerable benefits and raises some interesting questions regarding the way we design our road infrastructure, and has led neighbouring Bristol City Council and Devon Councils to undertake trials at a variety of sites. (Author/publisher)
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