Brent P:

That's why I generally don't signal lane changes untill right before I
make my move.

Commence flaming.

I don't think you're usually waking them up; I think most are just
driving with their ego.    There might be no prize for the winner and
the moral and practical justification for the contest  might be
questionable, but damned if they're going to "lose."

Of course, lane changing can be ego-driven as well; how often do you
see someone go to a lot of trouble to pull up a tiny bit ahead of you
and barge in, when he could have more easily dropped back into a
large gap just behind you?

There's also the vicious circle of malign self interest found at
congested urban off-ramps and connectors. (Commute traffic gets red in
tooth and claw pretty fast; or to reach for another literary image, we
have J.P. Donleavy's observation of how we all "drive along in our own
little mobile temples of discontent.)    Someone knows quite well
which lane he needs, but the lane he's in is going much faster, so he
sails along until the last minute and then tries to cut into the
line.  This tends to be bitterly resented by the people already there,
who close ranks to prevent him -- sometimes leaving his stranded with
nowhere to go and dangerously low speed in a lane where people want to
go fast; it also similarly strands people who are *not* trying to
snake anybody on their routine commute and just made an honest
mistake.

As fo the original topic, I would imagine that most people have little
concept of vector components or even much of a gut feel for how this
applies to driving.  I was taught that a lane change should be as
transparent as safety allows  to the guy you're merging in front of --
you find a gap, time your maneuver to arrive at it, and match the
*forward* component of your speed to what they're doing in the new
lane.  If he has to slow down (other than to drop back to a safe
following distance) or change lanes to let you in...  well, sometimes
heavy traffic doesn't give us much choice, but it is a less than
perfect lane change or merge.

Entering, exiting, and lane changing also have a  "6 P's" aspect  --
Proper Planning Prevents Piss-Poor Performance.  A lot of people think
rudeness or outright danger are good ways to make up for that, cutting
across three or four lanes at the last split second to take an exit in
a spray of gravel and litter from the gore point, for instance.  Or
they just don't have enough concern for others and awareness of the
world around them and how easily it can all go wrong to *realize* that
what they're doing is rude and dangerous.

And it all adds up to why tow trucks just go ahead and pre-position
themselves at  certain times and places, and why the orange barrels
and concrete dividers and guardrails are all smeared up with paint and
rubber.

--Joe

In article
<d69b5ac0-db99-4658-9892-ffe701861a0d@s37g2000prg.googlegroups.com>,

No, but a marginally sufficient gap is going to be easier to enter when
you are traveling slightly faster than the cars in the lane you're
trying to enter. Can you figure out why?