Also known as flocking. A collection of (automated) vehicles that travel together, actively coordinated in formation. Platoons decrease the distances between vehicles using electronic, and possibly mechanical, coupling. Platooning allows many vehicles to accelerate or brake simultaneously.
High density environment with an efficient high capacity public transport system with good capillarity and high frequencies.
Medium density environment with a good public transport system with radial connections to the city center, but lower capillarity and frequencies. This setting includes suburban cities.
Small, isolated city with an own public transport system and <100K inhabitants.
Low-density environment, small cities and villages with poor public transport services mainly connecting the villages.
The SAE (Society of Automotive Engineers) levels define the level of vehicle autonomy, or in other words, how much human intervention is still needed for an automated vehicle to operate. Currently, five SAE levels have been defined:
Level 0: Automated system issues warnings and may momentarily intervene but has no sustained vehicle control.
Level 1 (hands on): Driver and automatic system share vehicle control. The driver must be ready to retake full control at any time.
Level 2 (hands off): The automated system takes full control of the vehicle (accelerating, braking, and steering). The driver must monitor the driving and be prepared to intervene immediately at any time if the automated system fails to respond properly.
Level 3 (eyes off): The automated system takes full control of the vehicle (accelerating, braking, and steering). The driver must monitor the driving and be prepared to intervene immediately at any time if the automated system fails to respond properly.
Level 4 (mind off): As level 3, but no driver attention is ever required for safety, e.g. the driver may safely go to sleep or leave the driver's seat.
Level 5 (steering wheel optional): No human intervention is required at all. An example would be a robotic taxi.
Vehicle-to-everything (V2X) communication is the passing of information from a vehicle to any entity that may affect the vehicle, and vice versa.