The key idea of automation - in general - is to perform an action a skilled human operator could, but better/faster or more reliably. No automation removes the physical constraints, and sometimes new ones are added by the limited operation properties of the components involved, which, by the way, are also subject to errors and even failure.

Therefore, some expectations from automated functions are unrealistic, no automation system can guarantee no accidents in traffic, especially in mixed traffic conditions. Still, automation can offer enormous advantages as automated systems do not get tired, unattentive or distracted and can react much faster.