Driverless cars have moved with remarkable speed from DARPA-funded fantasy to picking up passengers on the streets of Pittsburgh. The excitement is justified, in part, because there’s much to gain. A single, shared autonomous vehicle could replace roughly 11 privately-owned vehicles, according to a recent University of Texas study. By reducing the number of cars on the road, self-driving vehicles could cut traffic, emissions, and urban sprawl, while improving safety and saving money for the millions of households that would no longer have to own a vehicle.

Yet we’re still a long way from adopting a futuristic fleet of driverless vehicles, and the main obstacle is navigation. Manufacturers teach their cars to move by employing fleets of drivers who travel the streets in ordinary cars, scanning for changes in previously mapped roads…

Source: Driverless Cars Need Just One Thing: Futuristic Roads