Slowing down is braking surely? His point was that there is rarely an accident the recreates the moral dilemmas of the trolley problems and I think he is right.
No, it's your last resort if you must slow down. Better drivers learn to coast, down-shift, or tricks such as using the slight uphill grade of a roadway to adjust speed without resorting to braking.
Next time you are driving and have good visibility far ahead in a long line of cars (such as approaching a big hill) watch for the cars with the brake lights coming on constantly. These are the less capable drivers, and once you spot them you will see them making other mistakes. For example, one trick I've learned is to watch for the driver's hand resting on the turn signal stalk in adjacent lanes as I approach. This is a tell that they are intending to cut me off. When I spot it, I can back off to anticipate them, or be more aggressive and accelerate to close the gap they were aiming for.
And to respond to another of Animat's original points humans aren't trained to brake/swerve in a harder, more risky manner for obstacles which are animate and not bother risking stopping at all for the unidentified object that appears to be a piece of cloth because unlike AI, this is not something we need to learn. (I agree with his original contention that pure software error and human inability to respond to it is a bigger problem than "trolley problems" with current generation tech)
anything that has a slowing or stopping effect.
See http://www.dictionary.com/browse/brake?s=t
The comment I replied to by tombrossman used the terms coast and down-shift, which are both commonly referred to as engine braking[1]
Slowing down as a result of a premeditated thought (does that kid play with a ball which might become loose? is that kid accompanied by his parents? is that kid really a kid or just a small adult person?) is more than mere braking, that's what I was trying to say.