25 January 2007

Naked streets

If you look carefully at the picture above, you can count no less than 22 sets of traffic lights. Those, complete with the paraphernalia of signs, barriers and bus segregation, is the classic response of the conventional traffic engineer - an expensive, sterile nightmare that magnifies the delays and frustration, destroying visual amenity.

Such a scheme could have been the response of the City Council of Smallingerland in Friesland, Holland. In the year 2000, the councillors and officials were about to implement a long-planned scheme to reconstruct an important traffic intersection in the City of Drachten, known as the Laweiplein.

Instead of taking the conventional route, however, they had called in Hans Monderman, a pioneering Dutch road traffic engineer. He has developed innovative designs for roads based on a concept known as "shared space". He claims it improves both efficiency and safety by taking a fresh look at assumptions about road design, vehicle physics, human perception, cognition, and culture.

His idea is that the road space is shared equally by all users - no one has right of way or priority His most famous approach has been labeled "designing for negotiation", which requires the different users to "negotiate" the space they are about to occupy. His designs get road users to focus on looking at one another instead of traffic control devices. Rather than zebra crossings, signs, lights, etc., he strips the furniture from the streets - hence the term "naked streets" - making it easier for users to see and negotiate with one another. His goal is to enhance the conspicuity and predictability of users, empowering them to cooperate with each another.

In partnership with the Regional Traffic Safety Office for Friesland, an intersection formerly controlled by traffic signals was completely redesigned to form a square with a roundabout in the middle - a "squareabout" (see plan, left).

Unlike others, it incorporated Monderman's principles, all intended, as the Council put it, to "transform the spatial quality of the Laweiplein." A thorough baseline study had been carried out and now, three years on, the experiment seems to have been a success.

Instead of the stop-start conditions of the original layout, traffic flows at a relatively constant rate. Moreover, the speed through the junction for cyclists and motorised traffic is roughly the same, a feature which improve the dynamic between all users, whether motorists, cyclists or pedestrians.

Traffic circulates more freely and although peak-time queues still build up, traffic generally keeps moving at a constant low speed. And it is that constant speed which gives the advantage: average times to cross the intersection have fallen from 50 seconds to about 30 seconds. Observed delay times appear to be shorter than the predictions given by roundabout models. Observers agree that there is clear indication that capacity has improved on conventional roundabout designs.

Delays for scheduled buses have also declined since the reconstruction. Formerly buses had priority transponders for the traffic signals, and average waiting times were around 53 seconds during peak hours. Now the average waiting time to cross the roundabout is 26 seconds heading towards the nearby bus station. The waiting time in the opposite direction is around 38 seconds.

Pedestrians and cyclists now appear to cross the intersection without significant delay. Most do not have to pause or wait, and are ceded priority by drivers. This appears to be associated with the overall slower traffic speeds. A remarkable number of cyclists use hand signals to indicate their intentions. Between 51 percent and 81 percent use left hand turn signals, and between 9% and 47% use right hand turn signals. Such signals, remarks the official report, are not common amongst cyclists in The Netherlands. Thus does the report conclude:

The reconfiguration of the Laweiplein into a squareabout has reconciled the seeming conflict between its highway role and its function as a public space. The spatial quality of the square has improved Traffic safety in terms of accidents seem to have improved to date since the removal of traffic signals. However, it should be noted that full accident data for the three years since reconstruction was not available. Further comparisons and analysis of longer periods will provide more definite conclusions about traffic safety at the Laweiplein.
Putting the theory to the test this week was Owen Paterson, Conservative shadow tansport minister, who decided to discuss the scheme with Hans Monderman, standing in various positions on the roundabout. However, an activity which might have been considered suicidal in England, and would certainly have provoked horns blaring and the delivery of some serious Anglo-Saxon vocabulary, had no effect other than to have cars and trucks steer round him.

The expedition itself was noticed by The Times, with Transport Correspondent Ben Webster citing Paterson as saying that traffic lights, road signs and white lines would be removed from many high streets across the country under Conservative proposals to improve safety and reduce congestion by giving drivers and pedestrians equal status.

He went on to say that road humps, chicanes and other physical measures designed to reduce the speed of vehicles would be removed and the question of who had priority would be left open deliberately, making drivers more cautious.

All this was based on the findings from now a multiplicity of the so-called "shared-space" schemes in the Netherlands, where pedestrians, cyclists and cars are encouraged to mingle. Kerbs in several Dutch towns have been removed and the boundaries between the pavement and road blurred deliberately to prevent people from assuming they have right of way. Said Paterson,

It's the opposite of the 1960s ethos of separating cars and pedestrians. By removing road signs and traffic lights and changing the appearance of the road, you avoid the impression that areas are designated just for cars. The idea is to create space where there is mild anxiety among everyone so they all behave cautiously. No one thunders along at 30mph on a high street thinking that they have priority.
Rather nervously, some aspects of the shared space approach have already been adopted on London streets. At Seven Dials in Covent Garden, the road surface has been altered to give it the appearance of a pedestrian area and kerbs have been lowered to encourage people to wander across the street.

In Kensington High Street (pictured), 600 yards of railings have been removed to allow pedestrians to cross where they want, discrediting the belief that railings prevent accidents. In the two years after they were removed, pedestrian casualties declined three times faster than the London average. Traffic engineers, says The Times, believe that drivers are now keeping a sharper eye out for pedestrians because they know that they may cross at any point.

The Royal Borough of Kensington and Chelsea is planning to introduce shared space ideas to Sloane Square next year. The aim is to encourage pedestrians to make greater use of the square, which is currently marooned by busy roads. A similar scheme is being planned for Exhibition Road.

So far, though, the roll-out in the rest of the country is minimal. Instead, we see the growing proliferation of traffic control devices - from the ever-present traffic lights to the hated speed cameras. And, with the EU set to take greater control over road safety, we can expect to see more and more regulations and even more attempts at controlling driving behaviour through mechanistic control devices.

But, says Paterson about the "shared space" scheme: "Instead of the State laying down the rules, we need to give responsibility back to road users. It's about creating an environment where it just doesn't feel right to drive faster than 20mph." That is an important lesson which has far wider implications. All too often, regulation has effects opposite to that intended - the so-called "sledgehammer to miss the nut" effect. Mr Monderman's ideas show that there are better ways.

But is the EU even capable of listening?