Robocars find it far harder to drive in cities than on highways because of pedestrians, cross traffic, and a forest of strange objects; that's why the early tests will be limited in scope. Volvo's 100-car test fleet will thread its way through just 50 kilometers of carefully reconnoitered roads in the Swedish city of Gothenberg, and the driver will always have the option of taking back control. Indeed, studying the handing off of control is one of the points of the experiment.
"The test cars are now able to handle lane following, speed adaption, and merging traffic all by themselves," said Volvo's Erik Coelingh, in a statement. A little over a year ago, Coelingh wrote for IEEE Spectrum on a first step-toward autonomy: cars that play follow-the-leader behind a truck driven by a human being.
In February he told Spectrum that much hard work will remain even after all the problems posed by this Gothenburg test are solved. "We can do this for a limited number of roads, but to scale the verification path is really challenging." Ten cars or 100 cars driving along 50 or 500 kilometers of well-mapped city streets is one thing; millions of cars moving through the cities of the world is another.
A lot of companies are working on the problem, including Audi, Mercedes, General Motors, and Nissan, which has set itself the target of selling autonomous cars by 2020.