

Highway Handbook: Why We Speed - dmuino
http://deadcatbounce.com/features/featurescat/highway-handbook-why-we-speed

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teilo
My wife's uncle taught a AAA defensive driving class for the elderly. The AAA
approved course at that time (this was in the mid-90's) taught them that the
safest speed is the average speed of traffic, regardless of the posted speed
limit. If they could not drive comfortably at that speed, then they should
stay in the right lane. If they were driving much slower than traffic and
could not comfortably drive any faster, they should avoid the highways
altogether.

~~~
thaumaturgy
Correct, and in California, this is codified as a traffic law.

Unfortunately, it is almost completely unenforced. Highway patrol and local
agencies instead focus on speeders -- including those doing 5 over in highway
"safe zones" -- because the fines for that are much higher, and it's less
defensible in court.

~~~
hristov
It is not codified as traffic law. California traffic laws encourage you to
follow the general speed of traffic, but only if that speed is legal vis-a-vis
the speed limits. If you speed, saying everybody else was speeding is
technically not an excuse.

~~~
thaumaturgy
CVC 21654: <http://www.dmv.ca.gov/pubs/vctop/d11/vc21654.htm>

~~~
hristov
I think we are talking about different things. Yes, there is a rule that says
that if you are driving slower than other traffic you should go into the right
lane. But nothing in this rule or any other rule gives you a right to drive
above the speed limit even if everyone else is driving above the speed limit.

~~~
invisible
It actually does say (from my reading) that speed limit shall not be a factor
if other traffic is going a similar speed. The very first line,
"Notwithstanding the prima facie speed limits..." is where I got this
explanation.

~~~
thaumaturgy
Well, yes and no. Oddly enough, I think everyone is right in this section of
the thread so far:

teilo said, "the _safest_ speed is the average speed of traffic, regardless of
the posted speed limit." This is true; it may not be the legal speed, but a
vehicle doing 60 MPH on a highway where the average vehicle speed is 80 MPH is
indeed a traffic hazard, regardless of the posted speed limit.

teilo also said, "If they could not drive comfortably at that speed, then they
should stay in the right lane." This is what I was responding to when I said
"it" was codified as law, and provided a citation.

hristov responded by arguing that this doesn't make it legal to go over the
posted speed limit: "But nothing in this rule or any other rule gives you a
right to drive above the speed limit even if everyone else is driving above
the speed limit." And he's right, too. By my reading of that law, it merely
says that slower traffic must move as far to the right as possible. I don't
think "notwithstanding" in that case means that the drivers can ignore the
posted limits, although that's certainly unclear and a point of
interpretation.

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boredguy8
"Drivers traveling at the limit should get a string of green lights."

I wish more civil engineers followed that. Realistically, there are a lot of
other concerns leading to traffic flow management. For instance, some cities
work with CHP to disrupt traffic flows in order to better stagger traffic
entering the freeway.

Determining the effectiveness of this strategy is left to the reader.

~~~
jimfl
Also remember that lights timed for 35 are also timed for 70.

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villiros
By the way, this article first appeared in a recent Something Awful thread. It
is very long but has heaps of information for anyone interested in highway
design.

[http://forums.somethingawful.com/showthread.php?threadid=317...](http://forums.somethingawful.com/showthread.php?threadid=3177805)

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jrockway
Some good reading on HN today. Thanks for posting this.

