
Roundabouts: A Misunderstood Intersection - gruez
http://wabe.org/post/roundabouts-surprising-facts-about-misunderstood-intersection
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_ambigu0us_
My favorite local junctions is the magic roundabout in Hemel Hempstead, UK
[1]. A traffic circle (roundabout with traffic lights) would have also worked
for this junction, but instead they used a ring of mini roundabouts, one
placed at each entrance/exit road, connected to one another by short dual
carriageway sections.

This allows for traffic to flow both ways around the circle, while forcing
drivers on the "roundabout" to slow down to navigate the mini roundabouts,
while not forcing people to stop completely for lights. In practice it works
incredibly well, maintaining a steady flow of traffic even under heavy
congestion. IMO it works far better than a controlled roundabout, and it a lot
more fun!

It's also a favorite for driving test examiners...

[1]
[https://www.google.co.uk/maps/place/Hemel+Hempstead,+Hertfor...](https://www.google.co.uk/maps/place/Hemel+Hempstead,+Hertfordshire/@51.7461757,-0.4733136,253m/data=!3m1!1e3!4m2!3m1!1s0x487640d05cd71ac1:0xf0e07f1fcfdff2b2?hl=en)

~~~
cjrp
Minor point, a roundabout with traffic lights is a gyratory

~~~
_ambigu0us_
I did not know that term, thanks!

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stinos
_2\. As you exit, it 's nice to use your turn-signal to alert the driver
behind you._

I always thought the main point of using your turn-signal is (apart from that
it is the law, at least where I live) to alert the ones _in front_ of you,
i.e. so that drivers wanting to enter the roundabout know they can do so
already without having to wait for you because you're leaving it anyway and
hence leave a void where the next car can enter?

~~~
andyjohnson0
I'd never enter a roundabout with an approaching car signalling that they are
intending to exit. Some people wrongly signal early (they're actually
intending to leave at a subsequent exit), some set their indicator (turn-
signal) on when they entered the roundabout and just keep it on, some are
indicating because they changed lane on the roundabout. I've seen too many
side-on collisions in these situations.

Basically, I drive defensively and don't trust other people's signalling. (UK
driver)

~~~
stinos
_I 'd never enter a roundabout with an approaching car signalling that they
are intending to exit_

Too late to edit but thinking of it, neither do I. It just allows you to start
planning/reacting earlier.

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nowprovision
Roundabouts have started appearing in Thailand, a country where most of
driving population do not hold any form of driving license and had only minor
handed down informal training, the results are comical, although there is
probably some scientific value that can be taken away if studied seriously.
The most common observation I found is that most give way to entering traffic
(i.e. they stop in the roundabout), there are of course less common instances
of going around with hazard lights on, and going the wrong direction, and even
just driving over them completely ignorant, by less common I mean <20% not the
exception you witness elsewhere. If you're on holiday in Koh Samui, Thailand
and from a country where roundabouts are popular then this location
[https://www.google.com/maps/place/Ko+Samui,+Thailand/@9.5340...](https://www.google.com/maps/place/Ko+Samui,+Thailand/@9.5340885,100.060806,70m/data=!3m1!1e3!4m2!3m1!1s0x3054f1501c66266f:0xedd55abd3d7d8330!6m1!1e1)
will provide a good few minutes of free entertainment, just don't stand too
close to the road, luckily though an ambulance is usually stationed a few
metres away. Unfortunately this roundabout doesn't work (in terms of optimal
traffic flow) for the reasons above and unlike "a north Georgia town"
education isn't going to be possible when they have no license or training,
and more importantly not a care in the world.

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jasonkester
The problem with roundabouts in the states is circular:

Nobody likes them or knows how to use them so they need to have tons of signs
and restrictions on them so people don't kill themselves or go around the
wrong way (the ones near my parents house actually have stop signs at every
entrance). This complicates things and stops them working very effectively,
resulting in people not liking them or knowing how to use them right.

If they had simply dropped them in place without comment, people would have
spent a few weeks crashing into each other and then figured it out and they
would work fine.

~~~
petepete
Mythbusters did a '4 way stop' vs roundabout comparison a few years ago[0]. It
was interesting to see American drivers who were mostly unfamiliar with
roundabouts warming to them.

[0] [http://www.wimp.com/testroundabout/](http://www.wimp.com/testroundabout/)

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lucaspiller
One thing this and the comments really highlight is how different driving
styles are in different countries. I wonder how much this is responsible for
traffic accidents?

As an example:

\- In the US people aren't taught (or don't care about) lane discipline, where
as in Europe you will make people very angry driving slowly in the inside lane
[0]. As such undertaking is usually prohibited in Europe, where as it's
allowed in most cases in the US.

\- If you are waiting to cross an on oncoming lane of traffic and someone
coming towards you flashes their lights, in the Middle East it means "wait,
I'm coming", where as in the UK it means "go ahead, I'll stop".

[0] Italy is my favourite for this. People will come up behind you (doing
160km/h, while you are doing 130km/h and the limit is 110km/h :D) and start
tailgating and flashing their lights until you move.

