Image: RioPatuca / Shutterstock
A man in a Autonomous driving test vehicle. Image: RioPatuca / Shutterstock
The image is already ingrained in the public consciousness. The strangely bubble-shaped car, seemingly not from the production line of any established motor manufacturer. In the front seats, two people, smiling, looking ahead. But curiously, no hands where you’d expect to see them…because there’s no steering wheel.

It’s unnerving – were you to see it in the street, you’d stay well out of the way. But on the roads of the San Francisco Bay Area, where Google has been testing its driverless cars, it’s becoming an increasingly common sight.

So, when can we expect to see them in car showrooms? Well, that’s a little hazy. The likes of Audi, Hyundai and Google are into advanced testing for driverless vehicles. Google plans to launch its fully autonomous vehicle in 2020. But even that is an ambition, not a concrete date. There are a number of practical and ethical questions to answer first. If you were hoping to skip your driving test and have a car do all the work for you then you’re barking up the wrong tree. The cars are some way off and the tests are still likely to form a vital part of our learning process even after they arrive.

Why are we waiting? Here are some of the main reasons.

The only way is ethics
While driverless cars will be programmed to deal with thousands of different situations, there will always be something unexpected. Snap decisions that need to be made when, say, a child runs out into a busy road. Does the car swerve into oncoming traffic to avoid the child, thereby endangering its passengers and other road users? Should you have the power to override its programming? And could you set your own defaults?

These are hugely important questions, and the BBC points out that Daimler will be holding a conference later in 2015 with philosophers to find some answers. Humans might need to be trained up to step in should the car malfunction.

The blame game
That last point hints at another issue to be overcome when it comes to driverless technology. There’s no question this innovation will reduce accidents, given faster reaction times and the reduction of human error, and if it won’t come to pass if it doesn’t. But they’ll never be fully eradicated. So, when they do occur, who’s to blame? You, as the car owner? The car’s manufacturer? Not issues that can be solved by technology alone.

Is the technology ready yet?
We’ve already driven with the tech powering autonomous cars. Automatic reversing, adaptive cruise control and predictive braking are some of the examples of cars already using the sorts of features driverless cars will count on. The task now is to put all of those aspects together and build on this further. But the problem arises from sensors unable to see far enough ahead to react quickly to incidents further down the road. At the moment, sensor technology is able to detect what is happening some 200 to 300 metres ahead. But for driverless cars to have more time to react, they’ll need to be able to see more than 400 metres ahead.

There’s also the question of weather, especially here in the UK. Can sensors detect the road and other traffic in heavy rain, fog or snow? Even Google hasn’t tested its cars in snow yet.

Are we ready for them?
A lot of people simply like driving. The speed, the noise, being in control. Car enthusiasm is big business and classic marques such as Ferrari, Maserati, Aston Martin all promote the romanticism of rolling over sweeping roads with great power and responsiveness under your right foot. To take that away will surely only appeal to one sector of the car market – the part that uses cars only in the most basic, get-from-A-to-B sense.