Shared Space, the evidence on accidents

This post reviews some of the evidence about the ‘shared street’ campaign; and also  responds to a very interesting post on ‘As Easy as Riding a Bike – the delusion of shared space‘.

‘Shared Space’ is a concept that is gaining much praise for improvements to the street environment, and has emerged from a much larger movement looking critically at the previous rules for the design of streets.

Through the past 60 years residential streets have been governed by strict ‘rules’, latterly set out in Design Bulletin 32 (DB32), which stipulated requirements for forward visibility, junction radius, road curvature, junction spacing etc. The result helped in producing much vilified ‘anywhere estates’ across the country. Much of the design requirements were based on false assumptions that have now been tested (and are still being tested), resulting in the emergence of the Manual for Streets (CLG, 2007). This publication was followed by Manual for Streets 2 (DfT, 2010), promoting the concepts for residential streets for use in High Streets and other high volume traffic situations.

For some further history, together with some examples of recent shared space schemes, see this briefing document. For years many of our streets have been blighted by design primarily for traffic and smooth traffic movement; and in many cases historic streets praised by local Councils were impossible to replicate, because their own ‘rules’ forbade it. The new guidance in the MfS 1 and 2 overturns the status quo, and has already produced some much better residential environments.

Shared street and parking at Upton, Northampton

Shared street in Upton, Northampton

The idea of the new approach to residential street design was to consider environment first, with vehicle movement as a lower priority. The main aim was not to reduce accidents, but produce a better environment. Many residential streets have seen great environmental improvements, and data so far shows that accidents on these streets has not increased, and in many cases the ‘side effect’ of environmental improvements has been a decrease in accidents (see tables on pp30-31 of this Appraisal of Shared Space, DfT 2009).

In particular, Kensington High Street was one of the first high profile schemes to emerge from the wave of new street design placing greater emphasis on the physical environment and pedestrians. The street was ‘decluttered’ in 2000-2001 with signage and railings removed in favour of promoting eye contact between driver / cyclist and pedestrian in order to change driver behaviour.

The evidence points to widely reported reductions in accidents at Kensington High Street.

Years later, a greater variety of different schemes have been completed (including Ashford in Kent, and Exhibition Road in London) and the evidence is still being collected.

These schemes are not necessarily the panacea they might at first have seemed. Where vehicle levels are high, there is a danger that pedestrians will be intimidated. In Ashford, evidence from University of West of England shows that pedestrians are not using desire lines but giving way to vehicles, many feeling safer under previous street arrangements.

Caernarvon square

 

Whilst the Exhibition Road scheme was generally lauded (although not by ‘As Easy as Riding A Bike’ – see above), shortly after opening it suffered its first accident. Caernarvon square is hailed as a success. Opinions are divided, and the acceptance of different schemes varies greatly. It is important that the evidence base is improved so that we can weigh up the elements of these schemes that make them work, and what needs further improvement. No one wants to go back to the cutting edge street design of the 1960s and 1990s. A trip to Basingstoke will tell you that.

 

Vauville, Normandy: ‘shared’ street design

Vauville is a small village in Normandy, France. There is not heavy traffic throughout the day, although it becomes busier at peak hours and provides part of a tourist route.

A narrow road width, keeping traffic speeds slow, with a raised footpath on one side, and a footpath separated from the carriageway by a drainage channel, providing temporary road widening for passing vehicles, also slowing passing vehicles down. Minimal obtrusive signage.

A footpath on one side, with parking bays, garage and front door entrances delineated on the opposite side by a drainage channel and setts.

Temporary street closure without a song and dance.

Simple unobtrusive street lighting kept out of the way.

Separation of footway from carriageway without kerbs: the carriageway can be used by pedestrians and cyclists; refuge can be taken as necessary without needing to bump up kerbs.

Sustainable urban drainage.