Why don't we do it in the road? A new school of traffic
design says we should get rid of stop signs and red lights
and let cars, bikes and people mingle together. It sounds
insane, but it works.
By Linda Baker salon.com20Open ↗
/traffic_design/index.html
May 20, 2004 | It's rush hour, and I am standing at the
corner of Zhuhui and Renmin Road, a four-lane intersection
in Suzhou, China. Ignoring the red light, a couple of taxis
and a dozen bicycles are headed straight for a huge mass of
cyclists, cars, pedicabs and mopeds that are turning left in
front of me. Cringing, I anticipate a collision. Like a
flock of migrating birds, however, the mass changes
formation. A space opens up, the taxis and bicycles move in,
and hundreds of commuters continue down the street,
unperturbed and fatality free.
In Suzhou, the traffic rules are simple. "There are no
rules," as one local told me. A city of 2.2 million people,
Suzhou has 500,000 cars and 900,000 bicycles, not to
mention hundreds of pedicabs, mopeds and assorted, quainter
forms of transportation. Drivers of all modes pay little
attention to the few traffic signals and weave wildly from
one side of the street to another. Defying survival
instincts, pedestrians have to barge between oncoming cars
to cross the roads.
But here's the catch: During the 10 days I spent in Suzhou
last fall, I didn't see a single accident. Really, not a
single one. Nor was there any of the road rage one might
expect given the anarchy that passes for traffic policy. And
despite the obvious advantages that accrue to cars because
of their size, no single transportation mode dominates the
streets. On the contrary, the urban arterials are a communal
mix of automobiles, cyclists, pedestrians, and small
businesses such as inner-tube repairmen that set up shop
directly in the right-of-way.
As the mother of two young children and an alternative-
transportation advocate, I've spent the past decade
supporting the installation of ever more traffic controls:
crosswalks, traffic signals, speed bumps, and speed limit
signs in school zones. But I'd only been in Suzhou a few
days before I started thinking that maybe there's a method
to the city's traffic madness -- a logic that has nothing to
do with the system of prohibition and segregation that
governs transportation policy in the United States.
As it turns out, I'm far from the first person to think
along these lines. In fact, the chaos associated with
traffic in developing countries is becoming all the rage
among a new wave of traffic engineers in mainland Europe
and, more recently, in the United Kingdom. It's called
"second generation" traffic calming, a combination of
traffic engineering and urban design that also draws
heavily on the fields of behavioral psychology and -- of
all subjects -- evolutionary biology. Rejecting the idea
of separating people from vehicular traffic, it's a
concept that privileges multiplicity over homogeneity,
disorder over order, and intrigue over certainty. In
practice, it's about dismantling barriers: between the
road and the sidewalk, between cars, pedestrians and
cyclists and, most controversially, between moving
vehicles and children at play.
For the past 50 years, the American approach to traffic
safety has been dominated by the "triple E" paradigm:
engineering, enforcement and education. And yet, the idea of
the street as a flexible community space is a provocative
one in the United States, precisely because other
"traditional" modes of transportation -- light rail,
streetcars and bicycles -- are making a comeback in cities
across the country. The shared-street concept is also
intriguing for the way it challenges one of the fundamental
tenets of American urban planning: that to create safe
communities, you have to control them.
"One of the characteristics of a shared environment is that
it appears chaotic, it appears very complex, and it demands
a strong level of having your wits about you," says U.K.
traffic and urban design consultant Ben Hamilton-Baillie,
speaking from his home in Bristol. "The history of traffic
engineering is the effort to rationalize what appeared to be
chaos," he says. "Today, we have a better understanding that
chaos can be productive."
A few years ago, Hamilton-Baillie spent several months
researching traffic and street design in northwest Europe,
followed by a stint as a Loeb fellow at Harvard. A former
researcher at Sustrans, a sustainable-transportation
nonprofit agency, he has become a leading proponent of the
shared-spaces and second-generation approach, which he says
meets the needs of automobiles while returning streets to
their historic function as civic gathering places.
But the implications, especially in the United States, are
nothing less than radical. Reversing decades of conventional
wisdom on traffic engineering, Hamilton-Baillie argues that
the key to improving both safety and vehicular capacity is
to remove traffic lights and other controls, such as stop
signs and the white and yellow lines dividing streets into
lanes. Without any clear right-of-way, he says, motorists
are forced to slow down to safer speeds, make eye contact
with pedestrians, cyclists and other drivers, and decide
among themselves when it is safe to proceed.
"The more you post the evidence of legislative control, such
as traffic signs, the less the driver is trying to use his
or her own senses," says Hamilton-Baillie, noting he has a
habit of walking randomly across roads -- much to his wife's
consternation. "So the less you can advertise the presence
of the state in terms of authority, the more effective this
approach can be." This, of course, is the exact opposite of
the "Triple E" traffic-calming approach, which seeks to
control the driver through the use of speed bumps, photo
radar, crosswalks and other engineering and enforcement
mechanisms.
The "self-reading street" has its roots in the Dutch
"woonerf" design principles that emerged in the 1970s.
Blurring the boundary between street and sidewalk, woonerfs
combine innovative paving, landscaping and other urban
designs to allow for the integration of multiple functions
in a single street, so that pedestrians, cyclists and
children playing share the road with slow-moving cars. The
pilot projects were so successful in fostering better urban
environments that the ideas spread rapidly to Belgium,
France, Denmark and Germany. In 1998, the British government
adopted a "Home Zones" initiative -- the woonerf equivalent
-- as part of its national transportation policy.
"What the early woonerf principles realized," says Hamilton-
Baillie, "was that there was a two-way interaction between
people and traffic. It was a vicious or, rather, a
virtuous circle: The busier the streets are, the safer
they become. So once you drive people off the street, they
become less safe."
Contrast this approach with that of the United Kingdom and
the United States, where education campaigns from the 1960s
onward were based on maintaining a clear separation between
the highway and the rest of the public realm. Children were
trained to modify their behavior and, under pain of death,
to stay out of the street. "But as soon as you emphasize
separation of functions, you have a more dangerous
environment," says Hamilton-Baillie. "Because then the
driver sees that he or she has priority. And the child who
forgets for a moment and chases a ball across the street is
a child in the wrong place."
When it comes to reconfiguring streets as community spaces,
ground zero is once again Holland and Denmark, where
planners are removing traffic lights in some towns and
cities, as well as white divider lines, sidewalks and speed
limits. Research has shown that fatality rates at busy
intersections, where two or three people were being killed
every year, dropped to zero when controls and boundaries
were taken away. (This is food for thought among alternative-
transportation advocates in the United States, who extol
northern Europe as a model precisely because so much space
in these countries is dedicated to segregated pedestrian
spaces and bike lanes.)
A photo of a reconstructed intersection, "the Brink," in the
Dutch province of Friesland, provides more design details.
Until 1998, the Brink was a standard asphalt intersection
with traffic controls and segregated spaces. Today, the
entire area has been repaved with red bricks bordered by
sections of green railing. A raised piazza juts into the
middle of the intersection, but there are no sidewalks, road
markings, or right-of-way signs. Every day, 4,500 cars share
the space with cyclists and pedestrians who wander about
"the road" at will.
Hamilton-Baillie recalls visiting "the Brink" with Hans
Mondermann of the Friesland Regional Organization for
Traffic Safety, a planner who has redesigned several
intersections with second-generation ideas in mind. "I was
amazed to hear him say, 'Have you ever seen so many traffic
violations?'" said Hamilton-Baillie. "'No rules, no rules,'
he told me. 'You have to think.'"
Subvert, don't attack, the dominant paradigm. Or, as David
Engwicht, a shared-spaces proponent in Brisbane, Australia,
has written: "Implicit in the whole notion of second-
generation traffic calming is the idea that significant
social change only happens when we amplify the paradoxical
'submerged voice' as opposed to tearing down the 'dominant
voice.' Engwicht, a plenary speaker at the Walk 21 Cities
for People Conference in Copenhagen this June, argues that
controlling a driver's natural propensity for speed is
futile. A more effective approach is to engage the driver by
emphasizing "uncertainty and intrigue" in the street
environment -- for example, planting a tree in the middle of
the street instead of putting up a stop sign.
"Standardized signage and use of standardized road markings
should be reduced to a minimum," Engwicht writes. "As they
create predictability and contain no intrigue. They also
reinforce that a street belongs exclusively to the
motorists."
There's another step in the second-generation logic process.
Safety analysts have known for several decades that the
maximum vehicle speed at which pedestrians can escape severe
injury upon impact is just under 20 miles per hour. Research
also suggests that an individual's ability to interact and
retain eye contact with other human beings diminishes
rapidly at speeds greater than 20 miles per hour. One theory
behind this magic bullet, says Hamilton-Baillie, is that 20
mph is the "maximum theoretical running speed" for human
beings. (Evolutionary biologist E.O. Wilson has drawn
similar conclusions.) "This is of interest," he says,
"because it suggests that our physiology and psychology has
evolved based around the potential maximum impact on the
speed of human beings."
The ramifications go beyond safety, says Hamilton-Baillie,
to bear directly on the interplay between speed, traffic
controls and vehicle capacity. Evidence from countries and
cities that have introduced a design speed of 30 kilometers
per hour (about 18.5 mph) -- as many of the European Union
nations are doing -- shows that slower speeds improve
traffic flow and reduce congestion.
"This surprises many people, although mathematically it's
not surprising," Hamilton-Baillie says. "The reason for this
is that your speed of journey, the ability of traffic to
move smoothly through the built environment, depends on
performance of your intersections, not on your speed of flow
between intersections." And intersections, he says, work
much more efficiently at lower speeds. "At 30 miles per
hour, you frequently need control systems like traffic
signals, which themselves mean that the intersection is not
in use for significant periods of time. Whereas at slower
speeds vehicles can move much more closely together and
drivers can use eye contact to engage and make decisions. So
you get much higher capacity."
Combining slower speeds with a reduction in traffic
controls, in other words, may have more than public safety
and shared-space benefits. It also appears to profit the
driver. (This is the logic behind the modern roundabout, a
redesigned version of the classic traffic circle that is
replacing signalized intersections in the United Kingdom and
is gaining acceptance among transportation officials in the
United States).
"You can see this is the way to break out of the pro-car,
anti-car debate," Hamilton-Baillie says. "Because the shared
approach very much accepts the car as a vital useful
component in cities that will remain with us for some
generations to come."
Let's return to China for a minute. If traffic in the
world's most populous country provides a useful comparison
and contrast, it's because second-generation traffic calming
isn't about anarchy; it's about studied anarchy. In essence,
Hamilton-Baillie is advocating for a new field: one that
blends traffic engineering with urban design. Or, as he
titled an upcoming paper: "Urban Design: Why Don't We Do It
in the Road?" There's a place for highways and roads
dedicated solely to the movement of automobiles, he says.
Just not in the city, where streets constitute 70 percent of
all public space.
"You have to have a completely different approach to the
design of streets in the broad urban realm," he says. "You
have to make an absolutely clear transition between those
roads that are necessary, the state-controlled and
legislative world of the traffic environment, to the human-
controlled, culturally controlled world of the city, where
you pick up your rules not from what you're allowed to do,
but from a much more subtle and complex series of codes that
are implicit through design and environment."
"If I walk into your living room, I do not need a sign that
says, Do Not Spit on the Floor," he explains. "Indeed, if
there were such a sign, it would probably be
counterproductive."
Over the last few years, the shared-street concept has
emigrated out of mainland Europe to the United Kingdom. In
addition to home zones, which are cropping up in isolated
residential developments, the city of Manchester is
currently reconfiguring a major section of its central core
according to shared-space principles. Hamilton-Baillie
himself is working a project that he says is the first in
the country to bring together all the elements of second-
generation traffic calming: removing the road markings from
a road that runs past a primary school in the city of Bath.
It's a project, he says, that capitalizes on the area's
"rich urban morphology" -- St. James Square, the school and
a historic church -- to "create a series of places rather
than a single highway."
In the United States, as one might expect, policymakers
haven't exactly embraced the virtues of ambiguity and
uncertainty embodied in second-generation principles.
"Woonerfs are certainly being planned on private property,"
says James Daisa, a project manager at Kimley-Horn
Associates and a national expert on pedestrian-friendly
development. "But the concept has yet to come to bear on
public streets." City codes are part of the problem, he
says. The reluctance of traffic engineers is another.
Consider the case of Brookline, Mass., which installed a
woonerf in front of a Marriott Hotel last January. A
patchwork of brick pavings, the shared-space lacks big
curbs, and the sidewalk and street are all at the same
level. But as reporter Anthony Flint noted in the Boston
Globe, the public works department botched the entire
concept by painting white lines and big right-turn arrows on
the street, and placing yellow-and-black-striped rectangles
on the landscaped "bump-outs."
"It's clear that advocates and private developers aren't
sufficient to bring about a true woonerf," wrote Flint. "The
traffic engineers need to be in the room, and they need to
understand the concept. A fact-finding trip to the
Netherlands may be in order."
For their part, many American traffic engineers say one
critical ingredient is missing for a system built around
shared spaces to work in the United States: a communal
sensibility. "We live in a culture that gives so much value
to the individual and the expression of that is how we act
in a car," says Robert Burchfield, a city traffic engineer
in my home town of Portland, Ore., which is nationally
recognized for its preservation of public space and its
dedicated network of cycling lanes and pedestrian pathways.
"I'm not comfortable with less order when I can't get people
to go below 50 or 60 miles per hour."
But this, of course, is precisely the point; redesign the
street environment as an active community space, and you
equalize the power relationship between cars and human
beings "The real gain in urban quality does not come from
clawing back areas of the city from cars, as important as
that is," said Hamilton-Baillie, who gave a talk at the
Portland Department of Transportation last fall. "But the
next step is how you apply a broader approach to those areas
where you need cars and trucks, bicycles and shops, and
pedestrians and children's play, all those different
functions to take place in precious urban space."
Even if we're not ready to send our children merrily into
the street, many of us, intuitively, have already embraced
the concepts behind second-generation traffic calming. Like
most other parents, I've drilled into my kids the fact that
traffic lights and signs work for cars, but don't
necessarily serve pedestrians who want to make it across the
street in one piece. "Look left, look right, look left
again," I preach ad nauseum -- even when the walk signal is
green. And who can resist the symbolism associated with
recapturing the street for the (teeming) masses? It's not
quite the fall of the Berlin Wall, but the shared-space
approach overturns the landmarks of sedentary isolation --
everything from gated communities to skyrocketing childhood
obesity rates -- to celebrate the complexity and
contradictions of city life.
The absence of traffic controls means that people are out
for themselves; the trick is, they have to look out for
everyone else as well. Second-generation traffic design is a
curious mix of selfishness and altruism, of order amid
chaos. And, after a fashion, it just might work.
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