Recognise the limits of people
If you're driving, the law requires you to pay continuous attention to the road and traffic. But it's been well known for many years that human beings are incapable of closely monitoring, e.g. a radar screen, for long periods, without occasional distraction that will cause them to miss something they should have noticed. How many drivers can put their hands up and say they have never noticed something later than they should have done? Sensible people drive in such a way as to make allowance for occasional distractions, but even this doesn't totally deal with the problem. So self driving cars are the best way to deal with a vehicle's interaction with other moving traffic.