Perhaps the most exciting feature of these highly sophisticated sat navs is their ability to repeatedly remind elderly drivers who they are and where they are going.

“At first they are nice about it but if we don’t listen they start shouting and inflicting cruel wounds,” an elderly person said. “They’re just like carers really.”

The sat navs can also gauge the mood of a driver and play appropriate soothing music. “I was drinking for three days and had two hours sleep,” a typical driver said.

“The sat nav knew exactly how I felt. It sang MacArthur Park with me. I wouldn’t have made it home without it.”