Colin buchanan

Westminster’s traffic signal trial is long overdue. Current DfT advice from Manual for Streets and LTN 1/08 Traffic Management and Streetscape reminds designers that there is no statutory requirement for formal controls at junctions, and yet no evidence, advice or design tools to determine where and when this might be appropriate are available.

At most installations designed for peak demand, there are likely to be significant economic and efficiency gains from at least part-time signal control, with the possible use of flashing amber off-peak, already adopted across Europe, with pedestrian crossing stages called on demand to overcome safety concerns. A study by TRL for TfL in 2006 (PPR292) concluded, however, that safety concerns at simplified streetscapes are unproven. The shared space scheme in Ashford, Kent demonstrates that considerate, civilised behaviour in unregulated streets is possible. The removal of signals and the stop-wait-start cycle may ‘smooth’ traffic (vehicular and pedestrian) flow, but without co-ordinated trials at a wide range of junctions across the UK we will never know what benefits and opportunities there might be.