Battle cry of British street designer: ‘Remove traffic signals’

Poynton’s ‘double roundel’ intersection functions as a public space — despite handling 26,000 vehicles per day, including trucks and buses. Source: Ben Hamilton-Baillie.

The idea of “shared space” has captured the collective imaginations of North American urbanists — partly due to English architect and urban designer Ben Hamilton-Baillie, who presented at the Congress for the New Urbanism this year.

Hamilton-Baillie is heavily influenced by Hans Monderman, the late Dutch traffic engineer who promoted the idea that stripping streets and intersections of traffic signals, signs, paint, and other regulatory clues improves safety and performance. 

A square designed by Hans Monderman. Source: Ben Hamilton-Baillie.

While Monderman worked mainly in small Dutch towns, Hamilton-Baillie has applied these ideas successfully to thoroughfares with high traffic volumes. His talk at CNU was leavened with understated humor — albeit with radical overtones.

“I urge you to take out all of the traffic signals in every city in the US — it would be a very simple thing to do,” he told the audience of about a thousand people. Although the group applauded enthusiastically, I’m guessing most understood the statement as hyperbole. Shared space is not an all-or-nothing proposition, and urbanists can apply Hamilton-Baillie’s ideas in many ways.

Successful shared space examples are rising in Europe. They work, in part, due to very careful design. A critical element is to slow design speeds radically — comfortably below 20 miles per hour — so that pedestrians, bicyclists, cars, trucks, buses, and even handicapped people can mix in a continuously flowing dance.

The affect of speed on traffic fatalities, and the inflection at 20 mph.

The importance of  ‘edge friction’

Hamilton-Baillie fosters slow speeds through what he calls “edge friction” and close attention to elements such as pedestrian crossings. “We are learning how every centimeter of crossing counts,” he says. “We are keeping them as narrow as they possibly can be.” US street designers think in terms of feet — Hamilton-Baillie suggests that they need to start paying attention to inches.

Streets are among the most intractable problems for urbanists ­— shared space offers fresh inspiration. Urbanists in America previously fought more energetically for pedestrian-friendly streets with narrow lanes — only to crash into the brick walls of departments of transportation (DOTs) and fire chiefs.

In the last decade that struggle has been partly supplanted by working with engineering organizations and DOTs on better standards. While new standards represent an improvement, they tend to be bland and compromised. Perhaps Hamilton-Baillie can get US urbanists fired up again for better streets.

Here are some of the highlights from his talk:

• Monderman’s most radical design involved extending a primary school playground across a road in Noordladen, Netherlands. “You can’t drive into the town without becoming intimately familiar with the activities at the school. There are no signs at all. The drivers slow way down, and that slow speed is extended throughout the town,” he says, adding dryly: “An infinitesimally small number of people wish to kill children. It’s very encouraging.”

• The town of Poynton, England, received a shared-space makeover of an intersection with 26,000 automobiles per day, including heavy truck traffic, designed by Hamilton-Baillie. The adjacent High Street was rebuilt. The project cost 4 million pounds (about $6.5 million), and a primary motive was economic development. Half of the storefronts were closed at the time, Hamilton-Baillie reports.

High street in Poynton, with narrow travel lanes and lots of pedestrian space. Source: Ben Hamilton-Baillie.

Two lanes of traffic approaching the primary intersection in each direction were replaced with a single lane. “Most people thought we were mad. It was already congested.”

The  lights were removed and the offset intersection was repaved as a “double roundel” — shaped like the outline of a snowman — in pavers. Congestion dropped while pedestrian traffic has risen to 4-5 times the previously levels. Now all of the storefronts are leased and Poynton recently placed number 7 on a list of most livable places in Britain, he says. The project “gave us huge volumes of space for pedestrians, parking, much wider footways — people were amazed that within 10 minutes of opening it there were no more queues,” he says.

A 14-minute video, Poynton Regenerated, has received 176,000 views on YouTube in the last year and a half.

• “Edge friction” is created mostly with vertical elements on the sides of travel lanes. Lamp posts are placed very close to traffic. A canopy of street trees over the right of way, on-street parking, and even changes in pavement can contribute to this friction, which is the primary means of controlling design speed. Accidents, injuries, and fatalities plummet below 20 miles per hour (see graph at right).

Edge friction in Hennef, Germany. Source: Ben Hamilton-Baillie.

• Pedestrian crossings in Poynton were placed in diagonal patterns where people tended to cross. “It enables people to wander across the road wherever they are,” he says.

• On Poynton’s High Street, travel lanes are marked by darker pavement that is barely wider than an automobile.

• The new pattern is helping to bring civility back to the town. “What’s amazing about Poynton is the change in relationship between drivers and pedestrians, pedestrians and drivers, and drivers and drivers. As someone says on YouTube, people are just nicer to each other.”

• Exhibition Road in London, which handles 9,000 vehicles per day, was also given a shared space makeover. Other successful examples include a square in Sweden (11,000 vehicles per day), and a major street in Hennef, Germany, near Bonn.

• The Seven Dials intersection in London, which carries significant vehicular traffic including buses and trucks, was remade as a shared space intersection 25 years ago with a monument where people sit in the middle of traffic. “We have 25 years of data … It turns out to be the safest and least congested junction of its type in the West End,” he says.

• Public spaces and highways have opposite characteristics. Highways are regulated, impersonal, linear, single-purpose, and controlled by signs and markings. Public spaces are culturally defined, personal, spatial, multipurpose, and regulated through eye contact and individual behavior. “The worst urban spaces come when highways and public space clash. It works badly on both counts,” Hamilton-Baillie says.

• In cities and towns, the streets and intersections are public spaces and should be treated as such. 

• If you treat drivers like idiots, they will act like idiots — so give them fewer instructions and let them use their own judgment, Hamilton-Baillie recommends.