Drive (39 page)

The irony is that when we choose the “freedom” of driving, we are captive to the actions of the many—more captive, in fact, than the people who take public transit. Perhaps because their freedom is so often compromised, Angelinos tend not to be the most courteous drivers. When we first arrived in LA, Mike was amazed at how no one would let him in after he found himself in the
wrong lane. For the rest of my week there, I tried to let other cars in whenever possible—it was my small act of subversion.

While LA is famous for its traffic jams, congestion is a problem in cities all over North America. And it's not just frustrating and time-consuming; it's expensive and bad for the environment. Between the 4.2 billion lost hours and 2.9 billion gallons of wasted fuel, traffic costs the U.S. economy $78 billion a year. On an individual basis, each year the average peak-period driver spends an additional 38 hours in the car and burns another 26 gallons of fuel, most of it greenhouse gas–producing fossil fuels. Not surprisingly, the situation is worst for Angelinos—at a cost of an extra 72 hours and 52 gallons every year.

Before I left on my road trip, I paid a couple of visits to the University of Toronto, where Baher Abdulhai and Eric Miller are engineering professors who have offices next to one another—but very different perspectives on traffic. To get to work, Abdulhai drives his Mercedes E320 into the city from the suburbs; Miller walks about forty minutes and feels guilty when, after walking home, he hops into his Toyota Sienna minivan to drive his sons, through rush-hour traffic, to a hockey arena out in the suburbs.

When I asked each of them about the Spadina Expressway, which Jane Jacobs and other citizens stopped, I heard two opposing opinions. Miller thinks it was “absolutely” the right decision. If Toronto has a reputation around the world as an interesting place, he pointed out, it's not because of what's going on in the suburbs; it's the older downtown neighbourhoods, which would have been wiped out, that impress people. “We didn't need it. People don't need freeways to get downtown, and I think that's one thing we've proven,” he argued. “Toronto has boomed because we put transit in and we've encouraged people to live and work downtown.”

His colleague disagreed. Though Abdulhai grew up in Egypt and didn't arrive in Toronto until nearly three decades after the battle over Spadina, he thinks killing it was a mistake. “Freeways
are arteries, so you can't say, ‘I don't want to depend on my artery going to the heart, I'm going to clog it and rely on the tiny little vessels to feed the heart.' No, it doesn't work that way,” he said, adding that a city's arteries are essential for moving people and goods. “Extremes are bad in either direction: no highways whatsoever, you're going to choke the city; highways everywhere, it's expensive, you'll hurt the environment and they create overconsumption. So balance is the key.” Because he believes in balance, he sat on the board of GO Transit, the region's commuter rail and bus system, and is a big proponent of investing not just in roads but also in public transit.

Abdulhai is also the founder and director of the University of Toronto's Intelligent Transportation Systems Centre and Testbed. ITS takes advantage of information and communications technology to manage traffic in order to ease congestion, increase safety and reduce pollution. By monitoring traffic using cameras, global positioning systems and detection devices built into roads and then feeding the information into computers, it's possible to detect collisions and anticipate congestion, forecast how long the tie-ups will last and disseminate information to drivers or use it to decide to control access to roads, change traffic lights or even adjust speed limits. “All of these things are simply algorithms that are sitting in a computer sniffing the numbers and deciding how to play with them,” he explained as we sat in a conference room with a glass wall that gave us a view of the lab, which consisted of rows of computers and a wall of television screens showing different roads and highways.

I hoped Abdulhai would be able to answer a question I'd long had about traffic. I'd heard that even hours after the police have cleared away a crash, traffic continues to slow down in that spot. So, I wondered, does traffic have a memory?

“Yes,” he said, “we teach this to undergrads.”

Since a little traffic flow theory is necessary to understand the concept, he explained that the three main variables for describing
traffic are speed (the rate the cars travel on the road), volume (the number of cars that use the road) and density (the number of cars on the road at a given time). In the wee hours of the morning, a highway is likely to have little volume and low density, but as rush hour approaches, both the density and the volume increase until the road reaches capacity. At that point, because the cars are so close together, drivers will start to slow down, resulting in a drop in volume but an increase in density. Eventually, so many cars squeeze onto the road that the traffic reaches critical density, breaks down and results in a traffic jam. As more cars arrive, the boundary of the congestion moves farther and farther up the road like a shock wave. Once traffic starts moving again, there's another shock wave as the cars at the front of the congestion start speeding up. But it takes five to ten times longer than the original disruption for the second shock wave to catch up with the first one and the congestion to completely dissipate, meaning that if two cars collide and it takes the drivers six minutes to get their cars to the side of the road, it can take up to an hour before all traffic is moving again. It also means that if I come along forty-five minutes after the collision, I will hit the congestion much sooner than I would have had I travelled on that stretch of road half an hour earlier. “The whole highway is like an accordion,” he explained. “Whenever you pass through congestion, you don't need to see a burning car at that location—it could be another location another time and that congestion is spreading.”

He sketched a diagram on a piece of paper as he talked, but then went to get his laptop so he could demonstrate the theory on a computer simulator and show me how traffic engineers can ease congestion by controlling signal lights at the entrances to highways. Often called “ramp metering,” it's common in many American cities, especially in California. First, he let me see typical nighttime flow. “Everything is hunky dory,” he said. “It's fast, and when a few people join in from the on-ramp, life is rosy and nice.” He then increased the main flow to capacity so that the little black
cars on the screen slowed down but continued moving, though he kept the ramp closed so no cars could join the main flow. Even so, he explained, demand was high enough that something as simple as a jittery driver jumping on his brakes could create congestion. Then he opened the ramp, overloading the road and bringing the little cars to a halt.

But if cars flow onto the highway at a controlled rate, they don't create congestion. While he acknowledged that ramp metering is not popular with drivers, Abdulhai assured me that it is effective and pointed out that when highways are clogged, drivers can't enter them anyway. “So these guys,” he said, pointing to the cars on the simulator's ramp, “are better off if those guys move.”

But humans are funny creatures, and that means they're often the weak link in ITS. Many cities use signs to alert drivers about clogged routes—some even send the information to cell phones or directly to cars—but there will always be those who try to outsmart everyone else. If the sign on Toronto's Highway 401 indicates that the express lanes are moving slowly and the collector lanes are moving well, some drivers will inevitably conclude: “Hmm, everybody's going to the collectors now, so I'm going to take the express lanes.” One way to reduce this problem is to offer more explicit information such as specific travel time estimates for each route.

Another ITS technique, currently being tested in Europe, is dynamic speed control, or adaptive speed limits, which promises to reduce congestion by using signs that can change the speed limit on a road so cars won't simply roar up to a traffic jam at full speed. Drivers approaching a jam at one hundred kilometres per hour will only add to the congestion and be stuck longer. But if they reduce their speed to sixty kilometres, the slowdown may have a chance to dissipate before they reach it. This would be safer and reduce both gas consumption and driver aggravation.

As costs drop and more technology starts showing up in cars, ITS will become even more powerful. A traffic department could,
for example, use beacons to communicate to vehicles about a hazard or collision ahead. “The ITS guys have been doing all kinds of wonderful things in isolation, and we've been doing things in isolation,” GM's Tom Odell noted. “Someday, very soon, we're going to start to talk and this magic will start to happen.”

WHAT FRUSTRATES DRIVERS
the most is the unpredictability of their travel time, according to Shashi Nambisan and Walter Vodrazka, both transportation engineers at the University of Nevada, Las Vegas. They live in a city where the traffic is bad and getting worse: Vodrazka commutes a little over four miles, each way, in his Ford Taurus and sometimes it takes him six or seven minutes. Sometimes it takes as long as half an hour. So to avoid being late— and to spare himself a lot of aggravation—he tries to leave home no later than 7:45 to ensure he'll get to campus in plenty of time for his 8:30 class, even if many of his students are tardy.

When it comes to easing congestion, there are two opposing approaches. One view says we need to tame traffic, making do with the roads we already have; the other says we have to add capacity to serve the demand. Nambisan would prefer to avoid either extreme but knows that will require some behaviour modification, including changing when we travel and the routes we take. Employers must also play a role by allowing more flextime and letting people work from home more often. (Just think: if everyone who now drives to his or her job could work from home one day a week, it would mean a 20 percent drop in commuter traffic.)

For their part, transportation experts can introduce car-pool lanes, ramp metering and adaptive speed limits, but they are in a tough spot because they're trying to reduce congestion even as they know that they could do much more if the problem grew much worse. London introduced a congestion toll only after traffic slowed so much that people were willing to accept such a drastic measure. “But is that our role in society, as transportation
professionals?” asked Nambisan. “To get the system to a breaking point before we can get it better?”

Of course not, but we are hurtling toward that point nonetheless. Abdulhai favours using a variety of weapons—including ITS, the expansion and better management of transit, and road expansion. But for economic and environmental reasons, new roads are likely to be increasingly rare. Besides, adding more roads just attracts more cars. “You don't have to provide more capacity for cars; they'll go away, they'll find something else to do,” said Miller, citing Jane Jacobs. “You expand the road, you attract more cars; you shrink the road or keep it the same, you don't get more cars. People will adjust.”

Once again, Abdulhai didn't agree. Because of latent demand, new roads or lanes will attract more drivers and become more congested. So the expanded highway will be worse than the day it opened but better than the day before it opened, and the additional capacity means that more people can use the road.

When it comes to transit, he divides people into three groups. At one end of the spectrum are transit loyalists, who either love riding buses, streetcars and subways or can't afford to get around any other way. At the other end are people who are dependent on the car for a number of reasons—“some of them are good reasons, some of them are bad reasons”—and it's completely unrealistic to expect them all to start taking the bus everywhere. But in between is a segment of the population that will take whatever is most convenient, and there are two ways to sway these people: one is to make travelling on freeways a miserable experience, something that's gradually happening; the other, better approach, is to improve transit so people will take it because they want to, not because they have to. “If you increase highway capacity only and you ignore transit completely, then you're going in the wrong direction,” Abdulhai argued. “You're telling people their better option is the car and that is not what I'm promoting. I'm saying expand transit to accommodate transit users, expand highways to
accommodate the must-use highway users and make transit more attractive to the in-betweeners.”

But adding transportation infrastructure to our cities, while essential, is really just treating the symptoms rather than attacking the disease of bad urban planning. “Transportation begins with the way you build the city, and if there's a villain, it's not the car, it's the way we've built our city with single-use suburbs,” Miller said. “We put all the people here and we scatter office buildings and stores hither, thither and yon and we don't think about the transportation. We assume everybody can get there by car, but we don't think about the congestion that's created.”

Sprawl isn't the only cause of traffic, but high-density mixed-use development—which means residents have the option of taking public transit, riding a bike or walking—is part of the solution. “People just drive a lot more in lowdensity areas,” insisted the Sierra Club's John Holtzclaw, and that's why a growing number of cities are trying to change their development patterns. “We sometimes say—I don't know if you can quote me on this but—traffic congestion is our friend. Traffic congestion lets people know how bad things are.”

“Why do you say you're not sure I can quote you?” I asked.

“Because the right—the pro-sprawl people—will say, ‘Hey, they want this! They want you to have to live in traffic congestion.' No. We want them to move into some place that's more convenient so they don't have to live in traffic congestion.”