When a Google self-driving car edged into the middle of a lane at 2mph on St Valentine’s Day and struck the side of a passing bus, it was a scrape heard around the world. The accident, disclosed by Alphabet, Google’s parent, on Monday, was the talk of the Geneva auto show this week.

I would prefer a car driven by a computer to a car driven by a human who is distracted by a phone. One auto executive recounted in Geneva how a friend of his had been seriously injured when a woman who was texting at the wheel of a car drove straight through a junction and knocked him off his motorcycle.

The accident illustrates that computers and people make an imperfect combination on the roads. Robots are extremely good at following rules — often far faster and more efficiently then people, without getting tired, distracted or drunk. But they are no better at divining how humans will behave than other humans are.