If you asked 10 people to describe what a driverless car means to them you’d probably get 10 different answers. For some, it would mean a vehicle that they could get into and which would take them to wherever they wanted to go without them having to do anything. For others, perhaps cautious about the technology, they are more likely to imagine a car that has some automation, but which they could control in an emergency.
Full autonomous driving – is it actually achievable?
To help clarify things, SAE International has defined 5 levels of automation for connected and autonomous vehicles (CAVs), and these have been adopted as industry standard.
Level 0
The driver is in complete control of the car and there are no automated systems. Until relatively recently most vehicles were Level 0. If you’re driving a car over 10 years old then it will probably fall into this category.
Level 1
Also known as “hands on”, the driver controls all normal driving tasks such as steering, accelerating, braking, and parking. Some automated systems such as Cruise Control, Parking Assistance, or Lane Keeping Assistance will be built into the car. The driver must monitor the environment and be able to take full control at any time. Many cars in production already use some form of Level 1 technology.
Nissan Leaf
For example, Nissan’s Propilot Park in the Nissan Leaf takes over the entire system, controlling the steering, accelerator, and brakes. The technology can be used for parking in bays as well as for parallel parking.
Level 2
“Hands off” automation means the automated system can take full control of the vehicle for steering, accelerating, and braking. Despite this, the driver must be prepared to intervene if necessary. “Hands off” is not meant to be taken literally, and the SAE recommends that hands should remain in contact with the steering wheel to confirm that the driver can take over.
Tesla Model X
Tesla’s Autopilot feature, as seen in the Model S, X, and 3, falls into the Level 2 category. It is designed to assist with some onerous parts of driving and enables the car to steer, accelerate, and brake automatically within its lane.
Level 3
Level 3 is described as “eyes off” automation. The driver can turn their attention to tasks other than driving, such as using his or her phone, or watching a movie. The automated system will be able to respond to situations that need an immediate response, for example, emergency braking, but the driver will still need to intervene if alerted by the technology.
BMW Vision iNext
BMW claims its Vision iNext, scheduled for production in 2021, will have Level 3 autonomy. Although it won’t be fully autonomous for all roads all of the time, it should be able to take over on stretches of motorway or busy suburban arterials.
Level 4
The next level is “mind off” automation. It is broadly similar to Level 3 in that the driver does not need to monitor the environment. In fact he or she could go to sleep as no driver intervention is needed even in emergency situations. However, this level of autonomy is only supported in limited areas or under certain circumstances such as traffic jams.
Waymo
Although some manufacturers have been working on Level 4 cars, in reality all their cars still require safety drivers. The one exception is Waymo, the self-driving car company founded by Google. Waymo’s fleet of ride-sharing vehicles are at Level 4 but the conditions in which they are allowed to drive are limited.
Level 5
The Holy Grail for autonomous car makers. Level 5 means “steering wheel optional”. The car is fully autonomous, and no human intervention is required.
The 5 levels or automation
