Today most of the new cars are equipped with driver-assistance systems such as cruise control and lane departure warning. In a few years’ time, however, the pedals and steering wheel will disappear and the cars will be fully autonomous. To offer a common standard and reflect the  degree of autonomy, the German Federal Highway Research Institute (Bundesanstalt für Straßenwesen) has established five levels of autonomous driving.
Level 1: Assisted driving
Most cars on the road today are already Level 1 vehicles. Technical aids such as cruise control (which has been available since 1958), or the adaptive cruise control, assume subtasks of the vehicle’s control, allowing the driver to take his foot off the gas pedal. These types of assistance systems provide support rather than assume autonomous control.
Level 2: Semi-autonomous driving
Some cars, such as the Audi Q7, already drive semi-autonomously in certain simple situations – such as on the highway or in congestion. The driver assistance system can intelligently stay in the lane or maintain the distance to the car in front. In these situations, driver hands and feet can take a break. However, the driver has to consistently monitor the situation and be ready to intervene.
Level 3: Highly automated driving
The car drives on its own in limited situations, such as on the highway or in congestion – and does so without monitoring. The driver can even take his eyes off the road. Cars at this level can already communicate with each other. The Audi A8 was the first production vehicle to reach this degree of autonomy, even though many countries have yet to legislate for it.
Level 4: Fully automated driving
The car drives itself most of the time. Even on regional roads and in city traffic as well as challenging and complex situations – the car can manage without intervention. The vehicle still has a steering wheel, but the driver can turn his attention to other things while driving. In this case we are at the prototype stage: no production car with these features has yet been launched on the market, partly because of the lack of a legal framework for such vehicles.
Level 5: Autonomous driving
In this highest level of autonomous driving, vehicles no longer need a steering wheel. The cars are so intelligent and connected with traffic lights and other vehicles that they can move safely in all traffic conditions without further interference. At this stage, the driver is a purely a passenger.
Source: TOGETHER.net – Volkswagen AG
