I usually keep one in all my vehicles.  That's one major reason I like
diesels -- the fuel doesn't ignite as easily if there is a leak, or an impact.
And you're exactly right -- people won't do squat for you when you're in
trouble most of the time.  Its pathetic.  They just drive by and keep the
music cranked up.  It used to be truck drivers were the Knights of the Road
-- many still are, especially in the south.  Of course, a good looking
woman is more likely to get all the help she needs!  She is at the highest
risk though of being a victim.  The fear factor is very, very real for
motorists.  People won't stop, and I won't stop to pick up the hitcher, or
when a hood is up.  Too many scams.  Looks can be deceiving, and the
supremely evil, smart criminal murderer will go to any lengths to lay a
trap for the unwary.  How do you think Ted Bundy was able to kill all those
girls?  People are easily fooled, and there are a million possible
scenarios.  The main thing to watch out for is whether the location is
suitable to become a crime scene.  Isolation is number one, what is
incomprehensible to some is that even in public you can, you're still
isolated; for example, on the side of the interstate -- as you saw.  So,
its clear the risk of harm is just too great for me and my family to stop
and help in 99% of the situations.  But, in the open blaze, or serious
accident, people should stop if they can do safely and without causing
danger to others.  But, if you're broken down on the road and a tractor
trailer pulls over to help, chances are you're safe.
sorry I got off on some tangents,
hk

PS-- what kind of truck was it?