10-lane intersection without traffic lights is perfect for driverless cars

Ever think that the roads we use every day aren’t quite optimized for the amount of traffic on them? That they are unnecessarily slow and often poorly designed? The image above features a traffic flow design that eliminates unnecessary stops from the most complex, busy intersections imaginable.

The design was made by Li Xu, a then 22-year old student at the Harbin Institute of Technology in China. It was first posted in 2011, but I haven’t seen or read examples of it being used, so it seems like the concept has been ignored by the roadway community. And with good reason — asking any human to to navigate this along with dozens of other cars would be asking for trouble. With driverless, robot-driven cars though, the whole drive could be done smoothly without ever stopping, supposing the cars were clever enough to negotiate with each other and not grind to a halt given the sheer amount of activity at the meeting of these two massive highways.

The 10-lane, traffic light-free intersection uses a clover-leaf pattern to completely eliminate stops, despite the huge amount of cars passing through. Rather than being slowed down with a traffic light, yield sign, or stop sign, each car is given a frictionless path to get where it’s headed. This includes all possible turns and a full U-turn.

The more lanes and traffic on a road, the more complicated things get. The more complicated driving gets, the slower and/or more dangerous it is. But if you go too far in the other direction, there are problems as well. Without rules and restrictions, driving can get dangerous — just drive through an old-school traffic circle and you’ll quickly find out. That wouldn’t be a problem for a driverless car though, as no driver will be reading the paper, sipping his coffee, or dealing with a massive amount of road rage.

Li’s design trades off built-in slowdowns — like stop signs and reversible (aka suicide) lanes — for negotiations between automobiles. You’ll have to yield the right-of-way multiple times while navigating this intersection. This could lead to multicar pileups or it could save huge amounts of time and make the highway larger and more complex than ever. With the driverless car, sufficient sensing, and car-to-car roadway negotiation technology, we could start driving change along with the driver.