Automated cars already exist, with five levels of grading a vehicle's autonomous capability (0-5). We don't know an exact date that because it will depend on both the tech having been thoroughly tested on the roads, as well as the law that would allow automated vehicles to drive on public roads. You can see an article we wrote on the Best Self-Driving Cars (on our parent site, heycar) here: heycar.co.uk/guides/best-self-driving-cars

Level 0 vehicles might issue warnings, but you’ll have to do the work. At Level 1, you’re expected to do the bulk of the driving but you might get features like automatic emergency braking and parking assistance. The automated system takes control of accelerating, braking and steering at level 2. Even though it’s called hands-off, you’ll need to keep your hands on the wheel just in case. This is still relatively rare in the UK - although automation up to level 2 is legal. In fact, the Government has said it’s moving towards having fully self-driving cars on public roads by 2021.

At Level 3, the vehicle will make decisions by itself, such as when to slow down and perform manoeuvres. For example, Level 3 automation could do the driving for you in slow-moving traffic. This technology exists but it’s not yet legal in the UK to use on public roads. Level 4 lets you go to sleep or leave the driver’s seat while the vehicle is in motion. This sort of self-driving car is either geofenced (strictly limited to certain areas) or reserved for special circumstances like traffic jams. Level 5 is full automation and includes trialling robot taxis. They tend to lack steering wheels, pedals or other controls. As with Level 4, it's still in development and so not yet legal on roads.