PCM asks:
I wonder why, if the truck drive lost his brakes, he would try to make a turn
.
Physics. The act of turning decelerates you. If you take your foot off the gas, that is. Its not a great idea if you don't know who will be there in the spot your turn is aimed at. Not good for the person in that spot, that is. Aiming straight at a building or tree decelerates you too, but the driver instinctively knows that
that is not good for the driver.
I honestly doubt that the driver was thinking of physics, though it would be "an excuse".
I've been in this situation, that is "no brakes". My 21-year-old Acura Integra gives dashboard light messages for every possible thing
except a defunct master cylinder or a leaky brake line. I have had both happen (years apart). Absolutely no warning. You get a big red light for a leaky caliper, but nada for those 2 far more serious problems. When the master cylinder failed I had just gotten off a busy local highway. When the brake line went, a few weeks ago, I had just rolled into a gas station after getting off the same highway. Very close to the same spot. Pretty creepy!
Since both times I was almost stopped when the pedal went to the floor, neither I nor anyone else was in danger. When the master cylinder went, I was able to get brakes back by pumping them up, & actually slowly drove home that way. This was very stupid. When the line went, you couldn't even get pressure by pumping, as the fluid just leaked onto the ground. Which was just as well considering my stupidity the 1st time. If AAA didn't exist to tow people with no brakes, whatever else is it for?
Now, when I mention this to people they inevitably say "you could stop by putting your car in neutral!". Yeah, eventually. "You could stop by throwing on the emergency brake!" (which in almost all cars is cable operated, not hydraulic). Yeah, eventually.
I have to admit that none of these ideas came to my mind at the time, either time.
You can also stop by opening the door & using your foot as a brake; I've known people who did this.
You can also stop by aiming your car straight uphill (foot off gas!); mountainous twisty highways often have "runaway truck ramps" just for this situation.
The question is not "will you stop eventually" but "will you stop before something much bigger than you (that you've hit) stops
you".
Sorry again for misleading you all that it was my daughter's friend.