Autonomous cars: five reasons they still aren't on our roads

Elon Musk thinks his company Tesla will have fully autonomous cars ready by the end of 2020. "There are no fundamental challenges remaining," he said recently. "There are many small problems. While the technology to enable a car to complete a journey without human input (what the industry calls "level 5 autonomy") might be advancing rapidly, producing a vehicle that can do so safely and legally is another matter. Read more: Are self-driving cars safe?