How Do Traffic Jams Work?

At some point or another, every driver experiences the maddening frustration of getting stuck in traffic. But exactly how do traffic jams work? How is it that in a modern society with technology like driverless cars and Sophia the humanoid robot, traffic is still a major issue in many American cities? What causes traffic jams, and is there anything the average driver can do to prevent them?

There are no easy answers or quick solutions to the issue of traffic jams. Multiple factors can influence why traffic congestion happens, and while some of these factors are beyond the control of the average motorist, how a person responds to both other motorists and challenging driving conditions often contributes to the severity of traffic at any given time. When it comes to reducing or eliminating traffic problems, it will take nothing short of a group effort for us all to become smarter, more aware drivers.

  • Drivers Don't Maintain Consistent Speeds
    Photo: Sky 269 / Wikimedia Commons / CC BY-SA 4.0

    Drivers Don't Maintain Consistent Speeds

    One of the biggest detriments to the smooth and unimpeded flow of traffic is the fact that drivers don't maintain consistent speeds. Unless you're using cruise control, you're constantly slowing down and speeding up, often subtly and without even realizing your speed is fluctuating. This phenomenon is less attributable to driver error and more owing to human nature. One study found that the lack of consistent speed is a collective phenomenon, meaning when one driver's speed fluctuates, whether wildly or imperceptibly, others respond in kind.

  • Obstacles On The Road Present Issues
    Photo: Michael Wirtz / Wikimedia Commons / CC BY-SA 4.0

    Obstacles On The Road Present Issues

    The obstacles a motorist encounters on their commute will have a direct bearing on whether traffic jams develop. Car accidents are among the most common culprits. Road work and lane closures are also responsible for bottlenecking traffic. Even a minor obstacle, like a road narrowing slightly, can cause traffic to slow considerably. Conditions like these cause around half of all traffic jams that occur on any given day.

  • When There's A Break In Traffic, Drivers Accelerate To Catch Up With The Vehicle In Front Of Them
    Photo: Prime number / Wikimedia Commons / CC BY-SA 4.0

    When There's A Break In Traffic, Drivers Accelerate To Catch Up With The Vehicle In Front Of Them

    If you drive in heavy traffic on a regular basis, there are likely some things you're doing, however unknowingly, to contribute to the problem. One driving faux pas that many engage in occurs when there's a break in traffic. In this situation, drivers tend to speed up to get closer to the vehicle in front of them. Once they catch up, they naturally slow down to avoid a collision, but slowing-down becomes a problem. After you close the gap with the car in front of you and reduce your speed, drivers behind you have to slow down too. As a result, traffic congestion grows.

  • The Vast Majority Of Motorists Think They're Superior Drivers

    Another common reason for traffic is simple human hubris. 93% of motorists think they're better-than-average drivers. Obviously, this high number is an issue—and a mathematical improbability:

    "To make it a little clearer, only half of a group can be better than average at something, while the other half must be worse than average, and anyone falling in the middle is truly average; since most Americans think they are better than average at driving, it says something about our cognitive bias to overestimate our positive qualities and underestimate our negative qualities."

    The bottom line is that few drivers are as skillful and adept behind the wheel as they think they are. That confidence can lead them to think they're handling traffic effectively when they're really not.

  • It's Easy To Dehumanize Other Drivers
    Photo: Ginette M / flickr

    It's Easy To Dehumanize Other Drivers

    When a driver gets behind the wheel, they're entering a small, enclosed space that feels private and secure. This perceived safety can create a disconnect between drivers on the road, and such a disconnect makes it less challenging for people to dehumanize other motorists. It also makes it easier for any given driver to engage in less-than-kind behavior. When one doesn't see the full humanity of others, cruelty can rear its head with surprising speed. So drivers are more prone to be disrespectful and just plain mean because their understanding of and empathy for other drivers is minimized. When a motorist acts like a jerk and does jerk-y things, traffic issues like congestion and jams result.

  • There Are Too Many Cars
    Photo: Cherry933 / Wikimedia Commons / CC BY-SA 4.0

    There Are Too Many Cars

    There's no getting around the fact that there are too many cars and not enough road. More cars plus limited space naturally equals increased traffic congestion. This is a major problem for most large cities around the world. In Beijing, for instance, there are a million new cars on the road every single year. The government finally decided to only issue a certain number of new license plates annually through a lottery system. If this approach caught on stateside, traffic would decrease. But let's be honest: there's a slim chance of the approach taking off here—Americans love their cars way too much.