The Simple Solution to Traffic

Stuck at an intersection, you always watch unfold
the Fundamental Problem of Traffic. On green, the first car accelerates, and then the next, and then the next, and then the next, and then you, only to catch the red. Had the cars accelerated simultaneously you would have made it through. Coordination – not cars – is the problem, because we are
monkey drivers with slow reaction times and short attention spans. Even if we tried getting everyone to
press the pedal on 3-2-1-now would be challenging. This dis-coordination limits
how many cars can get through an intersection and when one backs up to the next, that’s when city-sized gridlock cascades
happen, taking forever to clear. In general, more intersections equals more
dis-coordination which equals more traffic. This is the motive behind big highways:
no intersections. Splits and merges, yes. Intersections, no. No stopping, no coordination problems, no traffic Well that’s the theory anyway. Intersections outside of a highway
will back up onto it. Again, because human reaction times
limit how many cars can escape the off-ramp when the light changes. But, even without intersections,
there would still be traffic on the highway. Traffic can just appear. Take a one lane highway with happy cars flowing until a chicken crosses the road. The driver who sees it brakes a little, the driver behind him doesn’t notice immediately
and brakes a little harder than necessary, the driver behind him does the same
until someone comes to a complete stop and, oh look, cars approaching at highway
speeds must now stop as well. Though the chicken is long gone,
it left a phantom intersection on the highway. This is what’s happened when
you’re stuck in traffic for hours thinking, “There must be a deadly pile up ahead”
and then suddenly, the traffic’s over with no wreckage in sight,
to your relief if you’re a good person and mild annoyance if you aren’t. You just pass through a
phantom intersection, the cause of which is long gone. And this phantom intersection moves. It’s really a traffic snake slithering down the road eating oncoming cars at one end
and pooping them out the other. On a ring road, a single car slowing down will start an Ouroboros of traffic that will last forever, even though there’s no problem with the road. If the drivers could coordinate to
accelerate and separate simultaneously, easy driving would return. But they can’t, so traffic eternal. On highways, traffic snakes grow
if cars are eaten faster than excreted, and they shrink if excreted faster than eaten, dying when the last car accelerates away
before the next car must stop. Now, in multi-lane highways,
there needs be no chicken to start gridlock. A driver crossing lanes quickly
with cars too close behind is enough to birth a traffic snake that lives for
hours and leagues. It’s this quick crossing that causes
drivers behind to over-brake and begin a chain reaction. But we *can* make traffic
snakes less likely by changing the way we drive. Your goal as a driver is to
stay the same distance from the car ahead as from the car behind at all times. Tailgating is trouble. Not just because
it makes accidents more likely but because you as the tailgater can start a
traffic snake if the driver ahead brakes. Always in the middle! This gives you the most time
to prevent over-braking but also gives the driver
behind you the most time as well. And when stuck in traffic, this rule would get all cars to pull apart the snake faster. That’s the simple solution to traffic:
getting humans to change their behavior, perhaps by sharing this video to show
how and why traffic happens, why tailgaters are trouble, and how we can work together to make the roads better for all. The End. Except, yeah… wishing upon a star that people are
better than they are is a terrible solution. Every time. Instead, what works is a
structurally systematized solution which is exactly what self-driving cars are. Self-driving cars can just be programmed to stay in the middle and accelerate simultaneously. They’ll just do it. The more self-driving cars at an intersection,
the more efficient the intersection gets. A solid lane of self-driving cars
vastly increases throughput. Hmm, actually! If you ban humans from the road
(which we should totally do anyway) you can get rid of the intersection entirely. After all, a traffic light is just a tool for drivers
on one road to communicate with drivers on another, poorly and coarsely. Red equals “Don’t go now,
we are coming through the intersection.” Green equals “good to go.” But self-driving cars can talk
to each other at the speed of light. with that kind of coordination, no traffic light necessary. Just as with the highway, the best
intersection is no intersection. Humans will never drive this precisely. At the intersection, the fundamental problem with traffic that you watch unfold, as well as everything, is people. So the real simple solution to traffic: is no more monkeys driving cars. This video has been brought to you
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