Re: Hard decision but Mercedes are probably right
There's a multi-level thing going on here, I think...
First level, you're driving watching what's in front of you and adjusting your speed and direction to avoid bumping into anything. Most of what's there is either stationary objects, objects doing much the same direction and speed (or the reverse vector).
Second level, you're considering what might be making changes to this situation: is that object that just stopped likely to open a door and emit a fleshy thing? Will the stationary object pull out in front of you? Will the objects coming down the slip road twenty miles an hour accelerate to your speed or wait for you to pass, or pull out in front of you moving more slowly than you?
Third level, you're considering potential hazards that should not but might cause changes to your surroundings. If you're passing a school at the end of the school day, you're going to be cautious; at 2 a.m. perhaps less so. But at 2 a.m. on the saturday morning past the club...
And so on. There's always one more layer of introspection regarding external conditions, many of which - but not all - are known locations at known times and can be mapped, and many which are completely random: the busload of nuns with a failed braking system vs. a tree struck by lightning and unsure which direction to fall in vs. a paraglider landing in the road in front of you.
Where do you stop? This is what meatbags do supremely well - even the ones who can't read the Sun without moving their lips seem to career around the streets for years without causing major mayhem. I'm not convinced, though, that in a serious incident either the said mouth-breather or the professional ethicist who is also an expert driver is thinking anything more than stercus stercus stercus moriturus sum