We’ve only begun to think through how self-driving cars could eventually reshape our roads, cities, and lives — for better and for worse.
They might, for example, make traffic lights obsolete. Which… is a little unsettling.
In the video above, researchers at MIT’s Senseable City Lab demonstrate how streets full of autonomous vehicles wouldn’t necessarily need stoplights everywhere. If the cars were communicating with each other, they could simply slow down a bit and “slot” their way through intersections at steady speeds without ever causing a collision.
There’s a real risk that self-driving vehicles could make our roads even more car-centric than they already are
The model for “slot-based intersections” is described in this recent paper in PLOS One. The researchers found that reducing reliance on stoplights would greatly cut down on delays and congestion. No more waiting for the light to turn green. Cars would lower their speed to fit into a “slot” and then breeze right through the intersection without stopping.
To be sure, this is all a ways off. As Kevin Hartnett explains in the Boston Globe, there are endless kinks to work out. The cars would need to communicate not just with each other but likely with a central traffic controller. And roads would have to be filled entirely with autonomous vehicles — if you had even one human driver, that could muck up the flow. A stoplight-free future is decades away, maybe more.
Even so, the possibility raises some thorny urban-planning issues that are worth thinking about now. Slot-based intersections obviously don’t work for places where pedestrians need to cross (or for bicycles). Presumably you’d still need stoplights there. Accommodating people who walk or bike is going to be a major challenge for autonomous vehicles (AEVs). There’s a real risk that in an AEV future, roads end up catering far more to cars than they do today — pushing everyone else out.
It’s a good example of how radically self-driving cars could remake our transportation systems, in positive and not-so-positive ways. As my colleague David Roberts says, it’s wrong to imagine that AEVs will simply replace conventional vehicles on the road in a 1-1 fashion and all else will stay equal. All else won’t stay equal. Massive systemic changes are likely to emerge from a future filled with AEVs — changes that are very difficult to predict in advance. It’s much like how the advent of the internet didn’t simply replace the postal service.
The end of stoplights is one example of a possible systemic change with far-reaching implications. No doubt we will discover many more.