Traffic (27 page)

But what is a sign actually telling a driver? As Carl Andersen of the FHWA pointed out during my visit, the same sign can mean two different things in two different places. Take the chevron warning sign, the one that looks like a mathematical “greater or less than” symbol. “You drive in Vermont and you see a chevron sign, you better start braking for that curve,” Andersen said. “You see that chevron in Connecticut, you better ignore it. They pick different rates of curvature to put these chevron signs up to provide that kind of warning. So even though there’s guidelines to do it consistently, there’s enough leeway in there that they do it at different times.” Nor does a sign always mean the same thing: “Bridge Freezes Before Roadway” does not tell the driver whether the bridge is frozen, and in July it tells the driver absolutely nothing. Should a “65 MPH” speed-limit sign say something else when it’s raining? Engineers have created costly dynamic signs in response to all of these issues, but the real question may be, At what point must common sense do the work of a sign?

If “Slow: Children” and “Deer Crossing” signs do not seem to have noticeable effects, it hardly seems impertinent to ask, Do traffic signs work, and are they really needed at all? This question has been raised by Hans Monderman, a pioneer who was, until his death in January 2008, perhaps the world’s best-known traffic engineer. It’s probably no accident that he became famous by turning his back on decades of received wisdom in his profession and created traffic plans—like entire major intersections without lights or signs—that were radical even by the standards of his native Holland. “The Netherlands is different,” noted Kerstin Lemke, a researcher at Germany’s Federal Highway Research Institute, as if discussing the openness toward sex and drugs in Amsterdam. “They’ve got things on the motorway we would never do.” Then again, the Netherlands has a better traffic-safety record than Germany, so maybe they’re on to something.

If people have heard of Monderman, they tend to recall something about “the guy in the Netherlands who hated traffic signs.” But there is, in fact, one traffic sign that Monderman loved. It stands at the border of the small village of Makkinga, in Friesland. It announces a 30 kilometers per hour speed limit. Then it says,
WELKOM
. Finally, it says:
VERKEERSBORDVRIJ
!! In English this means, roughly, “Free of traffic signs.”

A traffic sign announcing the lack of traffic signs is a good joke, but it’s also a perfect symbol of Monderman’s philosophy. The sign itself is superfluous, for a driver can see that there are no traffic signs in Makkinga. After all, Monderman pointed out, what do traffic signs actually tell us? One day, driving through Friesland in his Volvo, Monderman gestured toward a sign, just before a bridge, that showed a symbol of a bridge. “Do you really think that no one would perceive there is a bridge over there?” he asked. “Why explain it? How foolish are we in always telling people how to behave. When you treat people like idiots, they’ll behave like that.”

Monderman’s work was far more complex than a simple dislike of traffic signs. It revolved around a central theory that said there are two kinds of space: The “traffic world” and the “social world.” The traffic world is best exemplified by the highway. This world is impersonal, standardized, meant only for cars. It is all about speed and efficiency and homogeneity. Monderman, a great fan of the German autobahn, happened to like this world. The social world, on the other hand, is seen in a place like a small Dutch village. These are places where the car is meant to be a guest, not the sole inhabitant. The street has other uses beyond being a means for people to drive quickly from one place to another. Behavior is governed by local customs and interpersonal contact more than abstract rules. Monderman liked this world too, but he did not want it to have anything in common with the German autobahn.

Yet the traffic engineers, argued Monderman, with their standardized signs and markings, have forced the traffic world upon the social world. “When you built a street in the past in our villages, you could read the street in the village as a good book,” he said. “It was as readable as a book. Here is the entrance to the village, over there is a school, maybe you can shop in that shop over there. There’s a big farmyard and perhaps there’s a tractor coming out. Then the traffic engineers came and they changed it into an absolute uniform piece of space.” Drivers, he maintained, are no longer taking cues from the social life of the village; they’re working off the signs, which have become such a part of our world that “we don’t see them anymore.” Suddenly, the village’s main road is just another segment of the highway passing through, with only a few small signs to tell anyone otherwise. This may be why speeding tickets are so common at the entrances to small towns all over the world. Rather than the simple greed of the local municipality, it is also that the road through the village so often feels the same as the road outside the village—the same width, the same shoulders. The speed limit has suddenly been cut in half, but the driver feels as if he or she is still driving the same road. That speeding ticket is cognitive dissonance.

In the mid-1980s, Monderman had an epiphany that is still reverberating throughout the world. He was called in to rework the main street of a village called Oudehaske. Villagers, as they do the world over, were complaining about cars speeding through the village, on a wide asphalt road with steady traffic volumes. Before Oudehaske, Monderman’s response, like that of any good Dutch traffic engineer, had been to deploy the arsenal of what is known as “traffic calming.”

Traffic calming is, essentially, the art of getting drivers to slow down. You have traveled down a street on which traffic-calming measures have been applied, even if you were not aware of the taxonomy of devices. The most famous is the speed bump, the steep, jarring obstruction that dates to the dawn of the car itself. With the exception of places like Mexico City, speed bumps are mostly restricted to school parking lots and the like. What you see on streets nowadays is the “speed hump,” a wider, more gently sloping creature that, among other things, helps cities avoid lawsuits from car owners with ruined suspensions. There are a veritable Audubon guide’s worth of different hump styles, from “parabolic” to “sinusoidal” to the popular English import known as the “Watts profile.” A
really
wide hump with a flat plateau is called a “speed table.” Apart from these myriad undulations, there are also “chicanes,” which sound like French cigarettes but are really little S-shaped artificial curves that drivers must slow to navigate. “Neck-downs” (a.k.a. “bulb-outs,” “nubs,” or “knuckles”), meanwhile, are small extensions added to curbs to make intersections narrower, meant to induce drivers to slow and, at the very least, give pedestrians a shorter—and thus safer—distance to cross.

The list goes on—which should give you an idea of how hard it is to calm traffic—with any number of “diagonal diverters,” “median chokers,” and “forced-turn islands” (also called “pork chops,” for their shape). If you want to sound smart around your friends, just remember that engineers refer to bumps and the like as “vertical deflection,” while anything that relies on squeezing and narrowing is “horizontal deflection.”

Traffic-calming devices have been shown to slow speeds and reduce the volume of through traffic. But as with any medicine, the right drug—and the right dosage—must be administered. Many people think that stop signs are a good way to calm speeds in neighborhoods. One problem is that the power of these signs diminishes with use: The more stop signs, the more likely drivers are to violate them. Studies have also shown that stop signs do little if anything to reduce speed—drivers simply go faster at the midblock location to make up time. This issue plagues speed humps too, which is why engineers advise placing them no more than three hundred feet apart, so drivers do not have time to speed. As with any drug, there are side effects: Slowing and accelerating for humps increases noise and emissions, while studies have suggested that speed humps on one block can lead to higher speeds or more traffic on another. People opposed to traffic-calming measures have argued that they delay emergency responders, but researchers in Portland, Oregon, found that they added ten seconds at most to these trips—no more than any other random delay. Would you want to live on a neighborhood street that made the rare fire-truck visit ten seconds faster but was also a safe haven for faster, noisier, and more dangerous traffic every day?

As it happens, many of these traffic-calming innovations were first popularized in the Netherlands. In the beginning, they were almost impromptu acts, a kind of radical street theater directed against the growing encroachment of cars in the city. Joost Váhl, a progressive engineer working for the city of Delft in the late 1960s, was one of their key architects. Sitting one afternoon in his tidy house in Culemborg, Váhl recalled a series of outlandish stunts that ranged from a “dial-a-bump” service (citizens could call and request “bumps” in front of their homes), to the staging of a bicycle accident (“we wanted to know if car drivers would stop and help or pass us by”), to putting up false construction sites on city streets (“we found out that when streets are broken up for repair, everything is functioning perfectly with half of the space”). These tactics, which were really investigations into how to get cars and people to coexist in cities, eventually made their way into genuine social institutions. The most famous of these were the
woonerven
—the word translates roughly into “living yards”—which began to spring up in European cities in the early 1970s.

For decades, planners had said that people and traffic should be segregated, with cars on speedy urban motorways and pedestrians shuttling around on elevated networks of bridges and walkways. Many saw this as a capitulation of the city to the car, while as early an observer as Charles Dickens understood the futility in trying to get pedestrians to ascend pedestrian bridges when people preferred to simply cross at street level. (“Most people would prefer to face the danger of the street,” he wrote, “rather than the fatigue of getting upstairs.”)

The
woonerven
reversed this idea, suggesting that it was people who lived in cities and that cars were merely guests. Neighborhood streets were “rooms” to be driven through, at no higher than walking speeds of 5 to 10 miles per hour, with drivers being mindful of the furniture and decor—not just speed humps but benches, flowerpots, and nice cobble-stones—and, more important, the residents. Even today,
woonerven
plans seem radical, with children’s sandboxes sitting cheek-by-jowl to the street and trees planted in the middle of traffic. The reports that trickled in, however, talked about how children were playing outside longer, often without supervision. In time, the
woonerven
got their own traffic signs (a small icon of a house with a child standing next to it). These were marks of the concept’s success, but in the eyes of Monderman, those signs also rather defeated the purpose: Drive carefully near the
woonerven,
the sign implies, but drive less carefully everywhere else.

By the time Monderman had been called to rework the village of Oudehaske, the political winds of traffic planning had shifted, and suddenly things like speed bumps were out of favor. In any case, Monderman did not have the budget for traffic-calming infrastructure. At a loss, he suggested that the road simply be made more “villagelike.” Maybe if the road looked more like a village road and less like the highway leading out of town, people would act accordingly. The village, coincidentally, had called in some consultants to redesign the village itself. Why not extend the treatment to the road? Working with the consultants, Monderman offered a design. “I thought, this must go wrong. There were no flowerpots, no chicanes. It was just a simple road in a village, nothing more.” A month after the project was finished, Monderman took a radar gun and measured the speed of cars passing through the village. In the past, with his chicanes and flowerpots, he would have been lucky to get a 10 percent drop in speed. This time, the speed had dropped so much that he could not get a reading. “The gun only functioned at thirty kilometers per hour,” he recalled.

What had happened? Monderman, in essence, had created confusion by blending the car, bike, and pedestrian realms. What had been a wide road with clearly marked delineations was suddenly something more complex. “The width of the road is six meters,” Monderman told me as we stood on the sidewalk in Oudehaske. “That makes it impossible for two cars to pass each other together with a bicycle. So you’re forced to interact with other people, negotiate your behavior.” What adds to the complexity is that the road, now made of small paving blocks to give it a “village feel,” is two-tone: The center segment is red, and two small “gutter” strips running alongside are gray. Even though the strips are slightly curved to channel water, they are perfectly usable. “So when you look at the street it looks like a residential street of five meters,” Monderman explained. “But it has all the possibilities of a six-meter street. You can use it for all the traffic.” There is also, noticeably, a quite low curb. “The height of the curb is very low because both of the parts are parts of the one scheme,” he said. “We have the feeling we belong to one another. When you isolate people from each other by a high curb, ‘This is my space, this is mine,’ drivers drive faster. When you have the feeling that at this moment a child could drop in front of my car, you slow down.”

Monderman’s experiments were seminal steps in what would become known as “psychological traffic calming.” Rather than hit people over the head with speed bumps they would resent and signs they would ignore, better results could be achieved if drivers were not actually aware that they were slowing down, or why. “Mental speed bumps” is the delightful phrase used by David Engwicht, a gregarious traveling Australian traffic activist who for years had been tinkering, on a less official basis, with ideas similar to Monderman’s—even though neither knew each other at the time.