How to Teach a Car a Traffic Sign

Traffic signs are designed to flag down human drivers, relying on blocky shapes and bold colors to grab our gaze from long distances as we whoosh past at top speed. But how do you train a robot to spot and interpret these signs, in all their mystifying international variations?

That’s one of the many challenges facing autonomous vehicle (AV) pioneers like Google, Uber, et al. as they lay the groundwork for our self-driving automotive future. The sign problem is particularly knotty. The rise of AVs makes a stronger-than-ever case for standardizing traffic signage within national borders (road safety practitioners have long argued for the same thing, for human benefit), and possibly from country to country. Once humanity gives up the keys, we won’t need street signs at all—the robots will communicate with one another, and with the roads themselves, much more efficiently.