During a test drive near Ford’s Michigan headquarters, the team noticed something strange with its self-driving cars.
Each car shifted slightly at the same point in the lane “as if they were avoiding a pothole,” says Jim McBride, Ford’s senior technical leader for autonomous cars.
The problem wasn’t the cars — it was the map.
The team had just updated its 3D map of the test route, which helps guide self-driving cars. But a minor glitch caused one pixel on the map to have the wrong data value. It told the car a spot in the ground was raised 10 inches, when it was perfectly level.
“The new map looked perfect to the human eye,” McBride says. But not to the eye of a self-driving car. “A single incorrect pixel,” he says, was enough to throw off the cars.
The power of that tiny mapping glitch, which happened a few years ago, highlights the newfound importance of a product many consumers likely take for granted.
For much of the last decade, digital maps have helped people pull up basic directions while walking and driving. But tech and auto companies are investing in a new generation of maps for a much more demanding audience: self-driving cars.
These maps, often referred to as HD maps, go far beyond basic turn-by-turn directions. Some incorporate continuously updating data on lane markings, street signs, traffic signals, potholes and even the height of a curb — all down to the centimeter.
The maps help the car place itself in the world with a greater degree of accuracy, augmenting the sensors in the vehicle.
As an example, McBride says maps can guide cars when the lane markings are covered by snow or a truck is blocking the car’s view of a traffic signal. It can also free up car sensors to focus on detecting objects not included on the map, like pedestrians.
Maps may not get as much attention as videos of self-driving cars on the road, or the LIDAR laser sensors at the heart of a blockbuster lawsuit between Uber and Google (, Tech30). But they are a key piece of the puzzle under the hood.
Maps could help ensure safer deployment of self-driving cars in the next years. And they may just have the potential to create a new billion-dollar industry.