The royal couple tried out the system as part of a Luxembourg trade mission to the region.

The self-driving car, that doubled as a royal coach this week, is part of a “personal rapid transit” system developed by 2getthere, a Dutch company that builds “automated transit applications”.

This PRT system is a 1.4km carbon-neutral line connecting the North Car Park and the Masdar Institute for Science and Technology, which opened to the public in 2010.