I went for a drive in San Francisco’s Mission District last month. It was late morning, and there wasn’t much traffic. As I wended my way through the side streets, I avoided a double-parked armored car and steered around construction sites. Though it might have seemed like an aimless outing, my brief sortie was anything but. Every centimeter I drove, every object I encountered, and even the double line I crossed to avoid the Brinks truck was being recorded by a device affixed across the top edge of the windshield, just above the rearview mirror.

Steven Levy is Backchannel's founder and Editor in Chief. Sign up to get Backchannel's weekly newsletter, and follow us on Facebook, Twitter, and Instagram.

Soon, thousands of people might be installing those gadgets in their cars, hoping to make some extra bucks—and, in the process, contributing to the next great crowdsourced project: a ridiculously detailed and constantly updated map of the world’s roads, readable only by the vast swarm of self-driving cars that will populate our byways.

The device is made by a San Francisco-based startup called Mapper, which comes out of stealth today after a year of development. The company’s maps don’t resemble the classic gas station fold-outs, or even the ones made by Google or Apple that have supplanted them. They are meant for machines, not humans, and when you see them rendered, they are made up of glowing pixels where objects, lane markers, and traffic signals are delineated by rough shapes and tell-tale colors. These are the maps of the future, and allegedly the bedrock of a multi-billion-dollar market. Self-driving cars can’t operate without such maps.

The Mapper mapping device in action. Stephen Lam

“As humans, if we are blindfolded and dropped in a new place, we'll find our bearings—we have millions of years of common sense to help guide our awareness,” says Nikhil Naikal, Mapper’s CEO. “A machine, on the other hand, needs a large amount of up-to-date 3D map data to have foresight of what to expect around the corner. And that's exactly the kind of maps that we deliver.”

Currently, companies that are testing autonomous vehicles—such as Waymo (spun out of Google’s research division), Uber, General Motors, and others—have to make their own maps. It’s a painstaking process that requires people to drive vans equipped with sophisticated lidar (a combination of lasers and radar) equipment over designated roads in multiple passes to log every curb height, fire hydrant, and lane marking. As a result, those vehicles are virtually fenced in by the pre-mapped region; a Waymo car’s self-driving mode won’t even kick in unless it senses that it’s in a mapped zone.

Mapper’s solution is to create an army of part-time workers to gather data that will accrue to a huge “base map” for autonomous cars, and to update the map to keep it current. Think of the work as an alternative to driving for Uber and Lyft, without having to deal with customer ratings or backseat outbursts from Travis Kalanick.