Why arent we all riding in self-driving cars by now?
Nissans Quashqai is the latest car that can drive itself sort of (Picture: David Shepherd)  In 2015, the rate of development in the autonomous car world seemed incredible. Some analysts predicted there would be ten million self-driving cars on the road by 2020, while others suggested we would all become permanent back-seat drivers. Addison Lee claimed it would get self- driving taxis into London by 2021 but it hasnt happened  travelling from point A to point B still requires someone at the wheel. Getting a car to brake and accelerate automatically behind other vehicles, follow lane markings and stick to the speed limit  functions collectively known as level 2 autonomy  is pretty easy. There are plenty of cars that do it. Teslas autopilot system and Nissans pro-pilot tech in the new Qashqai are two such examples  but both require a driver in case things go awry. Cars like the Nissan Quashqai still need a driver to stop accidents from happening (Picture: David Shepherd)  Level 3 autonomy  where the driver can watch a movie or send a text  is far more complicated because while its easy to teach a machine the basic rules of the road, its exceptionally difficult for artificial intelligence to be taught the nuances required to drive safely. The stakes are high, as getting it right or wrong could mean the difference between life and death. Levels of autonomy and what they mean There are different levels of autonomy when it comes to driving (Photo by Alexander Koerner/Getty Images) Level 0  No autonomous features. Most cars on the road today operate at this level. Level 1  These vehicles can do one task autonomously such as braking, lane-keeping or adaptive cruise control. Drivers must be alert. Level 2  These vehicles are capable of handling multiple tasks such as keeping in the correct lane and braking. These vehicles need a driver to intervene. Level 3  At this level, cars are able to drive from point A to point B if certain conditions are met. In the case of an emergency, drivers are expected to take control of the car. Level 4  These vehicles are almost completely autonomous and dont require human intervention. However, they are restricted by location, speed and weather. Drivers are only occasionally expected to take control. Level 5  This is a fully self-driving car that can travel from point A to point B regardless of weather or speed. These vehicles dont need a driver at the wheel and can operate totally independently. It would take a very brave, or perhaps foolish, company to hand over a half-baked self-driving system to its customers knowing the limitations of the technology. It would take a foolish government to allow it too. And so outside of specific trials, self-driving cars arent yet allowed on our roads. Even if a manufacturer did think its cars were ready to drive themselves unsupervised, Joe Public wouldnt legally be able to go on a journey without being in full control of the vehicle at all times because level 3 autonomy is currently illegal in most places. That said, the British government is developing legislation to allow level 3 self-driving cars this year. It is hoped this will allow cars with automated lane keep assist (ALKS) to drive independently, albeit only with someone in the drivers seat, on motorways and only at speeds of up to 37mph  reserving its use only for congested sections of motorway. Whether this latest step actually happens, though, remains to be seen. The governments desire to usher in level 3 self-driving cars this year is exciting. Some would argue its only usable in a small number of situations and  is therefore nearly useless for the majority of drivers. There are also plenty of other potential shortcomings including the inability of level 3 cars to recognise smart motorway lane closures, crash debris or pedestrians in good time. While there are certainly some cases where level 3 autonomy might prove useful, level 4 autonomy is surely a more important step and one that more people would be able to trust. But that, unfortunately, is still some way off. In association with Cazoo. MORE : Shift to electric cars will add 10,000,000 more vehicles to UK roads, report claims  MORE : Watch the AirCar fly between airports, transform, then drive off down the road  How to get your Metro newspaper fix Metro newspaper is still available for you to pick up every weekday morning or you can download our app for all your favourite news, features, puzzles... and the exclusive evening edition! Download the Metro newspaper app for free on App Store and Google Play