Hong Kong International Airport says it’s ready to use driverless buses, confident it can shuttle passengers around the aerodrome from next year after extensive trials years in the making.

By bolting on cameras, sensors and tracking devices, the Asian financial hub’s main airport has adapted and kitted out an electric bus from Chinese carmaker BYD Co. and been testing so-called Level 4 autonomous technology. The four-year effort, using other types of driverless vehicles without passengers, has racked up around 130,000 kilometers (81,000 miles) without an accident, according to the airport…

A key part of the technology’s hardware is in a sizable, silver metal case next to where a driver would sit that contains the driverless unit and a back-up system that can independently scan the path ahead. If the main system fails, the back-up kicks in.