It was a game of Dots that pushed Erik Coelingh to rethink his entire approach to self-driving cars. Coelingh, Volvo's head of safety and driver assist technologies, was in a simulator, iPad in hand, swiping this way and that as the "car" drove itself, when he hear an alert telling him to take the wheel. He found the timing less than opportune. "They gave the message when I was close to getting a high score," he says. Jolted away from the absorbing task, he had no idea of what was happening on the "road," or how to handle it.

The first self-driving cars to be operated by ordinary British drivers will be left deliberately unmarked so that other drivers will not be tempted to "take them on", a senior car industry executive has revealed. One of the biggest fears of an ambitious project to lease the first autonomous vehicles to everyday motorists is that other road users might slam on their brakes or drive erratically in order to force the driverless cars into submission, he said. This is why the first 100 self-driving 4x4 vehicles to be leased to motorists as part of a pilot scheme on busy main roads into London will look no different than other Volvos of the same model, said Erik Coelingh, senior technical leader at Volvo Cars. The scheme will start in 2018. "From the outside you won't see that it's a self-driving car. From a purely scientific perspective it would be interesting to have some cars that are marked as self-driving cars and some that are not and see whether other road users react in a different way," Coelingh told the Observer.

If you could see that the car in front of you was being driven autonomously and therefore navigating in an ultra-safe manner, how would you react? Would you treat it as you would any other road user or be more inclined to torment it, knowing it would yield to your advances? It's a very real question that car makers and insurance companies are wrestling with and one that has prompted Swedish automotive giant Volvo to take preemptive action. The Guardian reports that it's decided that when the first 100 self-driving 4x4s hit London's streets in 2018, they'll look no different to any other Volvo of the same model so that other road users aren't tempted to "take them on." Those are the words of Erik Coelingh, senior technical leader at Volvo Cars: "From the outside you won't see that it's a self-driving car. From a purely scientific perspective it would be interesting to have some cars that are marked as self-driving cars and some that are not and see whether other road users react in a different way," he told the newspaper.

To judge by recent claims, "fully autonomous" self-driving technology is just around the corner. Uber Technologies Inc. is offering Pittsburgh residents rides in autonomous Ford Fusions. Ford Motor Co. F -0.08 %, BMW AG BMW -0.90 %, Volvo Car Corp. and Lyft Inc. say they will produce fully autonomous vehicles by 2021 or sooner. Tesla Motors Inc. TSLA 0.49 % Chief Executive Elon Musk, rarely topped in hyperbole, says the technology will be here within 24 months. To many industry insiders, these claims are largely hype.

No one's quite sure on just when people will be able to summon a self-driving car and go wherever they need to go. Too many variables--how the technology advances, how regulations are developed, what consumer acceptance looks like--remain for anyone to say, but that's not keeping Volvo from offering a date: 2020. The Swedes synonymous with safety want to eliminate all traffic deaths and serious injuries in their cars by the end of the decade. Because airbags, automatic braking and other active tech can only do so much, Volvo plans to use automated driving to do it. Next year, it plans to see how that tech works in the real world when it puts 100 customers in robocars for an extended beta test in Gothenburg, Sweden.