Authors: Tom Vanderbilt
Doesn’t matter what time it is. It’s either bad traffic, peak traffic, or slit-your-wrists traffic.
—The Italian Job
(2003)
“Sorry, the traffic was horrible.” These five words rival “How are you?” as the most popular way to begin a conversation in Los Angeles. At times it seems like half the city is waiting for the other half to arrive.
But there is one night when being late simply will not do, when the world—or at least several hundred million inhabitants of it—wants everyone to get to the same place at the same time. This would be Oscar night, when eight hundred or so limousines, ferrying the stars, arrive in a procession at the corner of Hollywood and Highland, depositing their celebrity carriage at the Kodak Theater. On the red carpet, the media volley questions: “How are you feeling?” “Who are you wearing?” But on Oscar night no one ever asks a larger question: How did eight hundred cars get to the same party in a punctual fashion in Los Angeles?
The answer is found in the labyrinthine basement of City Hall in downtown L.A. There, in a dark, climate-controlled room with a wall-sized bank of glowing monitors, each showing strategic shots of intersections across the city, sits the brains of the Los Angeles Department of Transportation’s Automated Traffic Surveillance and Control (ATSAC). Traffic centers like this one are essential in many modern cities, and one sees similar setups from Toronto to London (in Mexico City the engineers delightedly showed me footage of speeding drivers giving the finger to automatic speed-limit cameras).
The ATSAC room in Los Angeles would normally be empty on a Sunday, with only the quietly humming computers running the city’s traffic lights—ATSAC will even call a human repairperson if a signal breaks down. But since it’s Oscar night, an engineer named Kartik Patel has been in the “bunker” since nine a.m., working on the DOT’s special Oscar package. Another man lurks at a desk and does not say much. Teams of engineers have also been deployed in the field at strategic intersections. On a desk sits a little statue of Dilbert at a computer, to which someone has attached a label: “ATSAC Operator.”
Since the city cannot shut down the entire street network for the Oscars, the limos must be woven through the grid of Los Angeles in a complex orchestration of supply and demand. Normally, this is done by the system’s powerful computers, which use a real-time feedback loop to calculate demand. The system knows how many cars are waiting at any major intersection, thanks to the metal-detecting “induction loops” buried in the street (these are revealed by the thin black circles of tar in the asphalt). If at three-thirty p.m. there are suddenly as many cars as there normally would be in the peak period, the computers fire the “peak-period plan.” These area-wide plans can change in as little as five minutes. (For a quicker response, they could change with each light cycle, but this might produce overreactions that would mess up the system.) As ATSAC changes the lights at one intersection, it is also plotting future moves, like a traffic version of IBM’s chess-playing computer Big Blue. “It’s calculating a demand,” says Patel. “But it needs to think ahead and say, ‘How much time do I need for the next signal?’”
Over time, ATSAC amasses a profile of how a certain intersection behaves during a given time on a given day. Patel points to a computer screen, which seems to be running a crude version of the game SimCity, with computer renderings of traffic lights and streets but no people. An alert is flashing at one intersection. “This loop at three-thirty on a Sunday has a certain historical value, for a year’s period of time,” Patel explains. “Today it’s abnormal, because it’s not usually that heavy. So it’ll flag that as out of the norm and post it up there as a possible incident.” It will try to resolve the problem, says Patel, within the “confines of the cycling.”
But on this occasion, the engineers want certain traffic flows—those conveying the stars’ limos—to perform better than ATSAC would normally permit, without throwing the whole system into disarray. In the late afternoon, with the ceremony drawing near, it becomes apparent just how difficult this is. Harried requests are beginning to come in from field engineers, who are literally standing at intersections. “ATSAC, can you favor Wilcox at Hollywood?” asks a voice, crackling from Patel’s walkie-talkie. Patel, on his cell phone, barks: “Man, did you happen to copy Highland and Sunset? There’s quite a queue going northbound.” At times Patel will have his cell phone in one hand, the walkie-talkie in another, and then the landline phone will ring. “The limos are starting to back up, almost at Santa Monica,” someone cries through the static.
As Patel furiously taps on his keyboard, lengthening cycle times here, canceling a left-turn phase there, it becomes hard to resist the idea that being a traffic engineer is a little like playing God. One man pushing one button affects not just one group of people but literally the whole city, as the impact ripples through the system. It is chaos theory, L.A. style: A long red light in Santa Monica triggers a backup in Watts.
This is when it begins to look as if something odd is going on here this afternoon. Patel seems particularly concerned with the intersection of La Brea Avenue and Sunset Boulevard. “Yeah, Petey, what’s up?” he shouts into his phone. “How many people are there? That’s good.” Patel then admits that his unit has a “labor problem.” Some three hundred municipal engineers, on a sick-out, are picketing on the same streets on which the limos are trying to get to the Oscars. What better way to draw attention, and who better to know the streets on which to demonstrate? Some of the calls Patel receives are from engineers wondering why the limos have been held up, and some of the calls are from picketing engineers seeking updates about which intersections they should cross on foot. “Tell them to walk more slowly, they’re going too damn fast,” Patel says into his phone. Reports coming in say that police are hustling the picketers across the intersections, so as to not block traffic. “Oh my God, how can they kick you out? You have a legal right to cross. Any unmarked crosswalk, you can cross it…just keep on crossing there, moving slowly.”
Patel is both trying to get the limos to their destination
and
coaching the picketers on how to best interrupt that progress. Does that mean he can give the sign-toting pedestrians more time, which would further their cause? A strange smile crosses Patel’s face, but he says nothing. He later excuses himself and goes to an office in the back, where he takes phone calls. Is he a coconspirator? Or does his traffic-engineer side override his labor solidarity side? One cannot say for sure, but interestingly enough, Patel and another engineer were later charged with tampering with traffic lights at four key intersections as part of the ongoing labor dispute, and the case, which attracted the attention of the Department of Homeland Security, was in criminal court as of this writing, with the defendants facing several years in prison if convicted.
Despite the picketers, the limos arrive on time. The winning picture, ironically, is
Crash,
a film about Los Angeles traffic on literal and metaphorical levels. Then the limos leave the Kodak Theater, rejoining the city’s traffic, and head for the postevent parties.
That Oscar afternoon was a small but perfect illustration of how complicated human traffic is when compared to ant traffic. Ants have evolved over countless centuries to move with a seamless synchronicity that will benefit the entire colony. Humans, on the other hand, propel themselves around artificially, something they have done for only a few generations. They do not all move en masse with the same goal but instead travel with their own agendas (e.g., getting to the Oscars, staging a demonstration). Ants all move at roughly the same speed, while humans like to set their own speeds, ones that may or may not reflect the speed limit. And, crucially, ants move
as
ants. They can always feel their neighbors’ presence. Humans separate themselves not only across space but into drivers and pedestrians, and tend to act as if they are no longer the same species.
Los Angeles, like all cities, is essentially a noncooperative network. Its traffic system is filled with streams of people who desire to move how they want, and where they want, when they want, regardless of what everyone else is doing. What traffic engineers do is to try to simulate, through technology and signs and laws, a cooperative system. They try to make us less like locusts and more like ants.
Take traffic signals. It’s common to hear drivers in Los Angeles, as elsewhere, lament, “Why can’t they time the signals so they’re all green?” The obvious problem with so-called synchronized signals is that there is a driver moving in a different direction asking the same thing. Two people are competing for the same resource. The intersection, the fundamental problem of the traffic world, is an arena for clashing human desire. John Fisher, the head of the city’s DOT, uses the analogy of an elevator in a tall building. “You get on the elevator, and it stops at every floor because someone presses the button. They want to get off or on. Now, it stops at every floor—is it synchronized or not synchronized? The reality is if there are many stops, it’s going to take a while to get there. It’s the same with signals.”
Engineers can use sophisticated models to squeeze as much “signal progression” as possible out of a network, to give the driver the “green wave.” Fisher says that when he came to the DOT in the 1970s, “we tried to hold the line and keep the signals at a quarter-mile spacing.” By doing that, and setting the cycle time (or the time it takes to cycle through green, yellow, and red on the traffic light) at sixty seconds, vehicles traveling at 30 miles per hour could reasonably “expect to find a green.”
But over time, as the city has grown more dense, so too has the pressure to add more traffic lights. In certain places there is now a light at every block, which means there is a potential demand to cross at every block. Engineers have been forced to expand the length of the cycle to ninety seconds—typically the maximum in cities. “Let’s say you go to a ninety-second cycle,” Fisher says. “Even if you have quarter-mile spacing it means your progressive speed is not thirty miles per hour anymore, but something like twenty miles per hour. If you complicate that further, and the signal spacing is every block or sixteenth of a mile, there’s just no way you could progress from one end to the other. The best you could do is go a couple signals and stop, a couple signals and stop, in all directions.” The green wave works well on major streets where the demand from side streets is small. But in Los Angeles, Fisher explains, “we have traffic going in all directions, and generally the same quantities.” Some intersections receive so much competing demand that they are “oversaturated,” as Fisher says, beyond the help of even ATSAC’s computers.
To further complicate matters, there are, even in Los Angeles, pedestrians. Despite the hilarious scene in
L.A. Story
that showed Steve Martin driving to his next-door neighbor’s house for dinner, people do walk, and not just to and from their parked car. As a profession, traffic engineering has historically tended to treat pedestrians like little bits of irritating sand gumming up the works of their smoothly humming traffic machines. With a touch of condescending pity, pedestrians are referred to as “vulnerable road users” (even though in the United States many more people die in cars each year, which leads one to wonder who exactly is more vulnerable). Engineers speak of things like “pedestrian impedance” and “pedestrian interference,” which sound like nasty acts but really just refer to the fact that people sometimes have the gall to cross the street on foot, thus doing things like disrupting the “saturation flow rate” of cars turning at an intersection.
As a testament to the inherent bias of the profession, no engineer has ever written a paper about how “vehicular interference” disrupts the saturation flow rates of people trying to cross the street. In cities like New York, despite the fact that pedestrians vastly outnumber cars on a street like Fifth Avenue, traffic signals are timed to help move the fewer cars, not the many pedestrians—has anyone ever had an uninterrupted stroll up Fifth Avenue, a green wave for walking? Unlike in pedestrian-thronged New York City, where most push buttons to cross the street no longer work (even though they still tempt the impatient New Yorker), in Los Angeles the relative rarity of pedestrians means the buttons do work. The walker humbly asks the city’s traffic gods for permission to cross the street, and, after a time, their prayers are answered. If you do not press the button, you will stand there until you’re eventually ticketed for vagrancy.
Sometimes the traffic deities encounter even higher authorities. A curious fact of Los Angeles traffic life is that, at roughly seventy-five signals, in places ranging from Century City to Hancock Park, the button does
not
always have to be pressed to cross. These intersections run instead on what is known as Sabbath timing. As Sabbath-observant members of the Jewish faith are not supposed to operate machines or electrical devices from sundown on Friday to sundown on Saturday, or during a number of holidays, the act of pressing a button to cross the street is viewed as a violation of this tenet. With the only alternative rampant jaywalking, the city installed automated “Walk” signs at certain intersections (causing what Fisher jokingly calls “sacrificial interruptions” to traffic flow even when no pedestrians are present). “We have the Hebrew calendar programmed into our controller,” Fisher told me.