With its Shinkansen'bullet trains' and melodious subway system, Tokyo already has some of the world's greatest public transport infrastructure. But the heavily populated city will be pushed to its limits come 2020, when the world descends on the Japanese capital as it plays host to the Olympic games. One company looking to capitalise on the influx of tourists is robotics firm ZMP Inc. According to Reuters, it's planing to team up with Tokyo's Hinomaru Kotso cab firm to update its fleet of 600 cars with driverless technology. ZMP has already had driverless cars on Tokyo's streets, but each had a driver ready to wrestle control should the AI go wayward.