
The physics of traffic - petrel
http://360.here.com/2016/01/18/the-physics-of-traffic/
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TACIXAT
I absolutely love driving and think about it a lot. When I was in high school
we watched some video about the future highlighting self piloting cars and how
they could drive bumper to bumper. That doesn't make any sense though, you
need to leave space for lateral movements.

The problem as I see it is that most people think about driving as
competitive. They don't want _you_ to get in front of _them_. This is odd,
because someone who is passing one person will often carry on passing and be
out of sight in a minute.

This is where the idea of driving collaboratively comes in. If you let someone
merge, make their exit, pass you, you're enabling flow.

Instead, people drive competitively. They get as close as possible to
someone's bumper during a merge to ensure that only one (or potentially zero)
cars get in front of them. This forces people to stop or slow considerably
before someone can get in front of them. The same with passing, if someone is
blocking the fast lane, the passing car needs to slow considerably (affecting
cars behind them) and change lanes (affecting cars in another lane). Everyone
thinks it's about them, and some will even speed up when you try to pass as if
you are insulting the speed that they are driving. It's madness.

If I ever have a ton of money I'm going to take out a national ad campaign
encouraging people to drive collaboratively.

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mironathetin
"If you let someone merge, make their exit, pass you, you're enabling flow."

yes and no.

If you let someone merge in heavy traffic, and (s)he has to break hard right
after merging, the flow stops. This is what happens - indeed - in competitive
driving. In my city people seem to be so full of adrenaline, more before than
after work, that it happens all the time and already in the morning at 6:30.

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junke
See also [http://trafficwaves.org/](http://trafficwaves.org/)

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djaychela
Certainly an interesting topic and one which if exploited could improve travel
for many. My question, though is whether it's possible to improve the
situation without the recourse to technology? i.e. if you looked ahead on the
road and saw a small jam (but one at a distance which was say 400 meters
ahead), but which clears quickly, if a certain way of modulating your speed
would help? Or is the only way to recognise it late, and brake as hard as
possible (as I see so often!)?

~~~
dsfyu404ed
What you're speaking of if pretty much analogous to driving at speed toward a
light that just turned red the better part of a mile in the distance because
you know (from experience, e.g. your commute) that in the time it takes to
reach the light the light will change to green.

You're just making the location variable as well. This is a very common way of
doing things for anyone that drives something that has horrible acceleration
and a good view of traffic ahead (a typical forward control box truck full of
stuff). When a temporary obstruction is noted up ahead, such as someone
slowing for a right turn into a parking lot or it's easier to change lanes to
go around the obstruction than it is to slow and speed up again. When changing
lanes won't work, such as a bunch of cars that have yet to come up to speed
after moving on a green light then slowing down slowly so that they're caught
up to gradually is a viable alternative. Most people underestimate the amount
they need to slow and wind up tapping the brakes at the end so fears of this
causing unnecessary slowdowns are unwarranted IMO

Similarly, when encountering something like merging traffic on the right it's
easier to maintain speed and move left to give the clusterfawk caused by the
merging traffic space to run its course.

When driving a loaded truck the cost to slowing down is very high, these
things have 0-60 times in the teens when unloaded and when traveling in
traffic this is a pretty good incentive to avoid slowing down. The good view
of traffic ahead allows drivers to adopt a strategy for driving at a
consistent speed.

