
The UK is replacing roundabouts with traffic lights; US is doing the opposite - jonathansizz
http://www.theguardian.com/cities/2015/oct/19/traffic-lights-roundabouts-way-out
======
zb
I don't see roundabouts as a replacement for traffic lights in the US. Above a
certain traffic volume, you'll almost always want to move to traffic lights
anyway. They're actually a replacement for the 4-way Stop - a ridiculous type
of intersection that ought not to exist.

~~~
r0m4n0
Or my personal favorite in Sacramento, roundabout with some stop signs
sprinkled in. I hear horns and accidents daily...

[https://www.google.com/maps/@38.5801855,-121.4694376,3a,75y,...](https://www.google.com/maps/@38.5801855,-121.4694376,3a,75y,210.19h,69.12t/data=!3m6!1e1!3m4!1s3yb-E21Li76n8bfNCBpINw!2e0!7i13312!8i6656!6m1!1e1)

~~~
Tloewald
For true insanity you need to go to Washington DC which has roundabouts with
divided lanes, pedestrian crossings, traffic lights, stop signs, and turning
lanes.

[https://www.google.com/maps/place/Washington,+DC/@38.9092507...](https://www.google.com/maps/place/Washington,+DC/@38.9092507,-77.0429818,3a,75y,232.54h,89.8t/data=!3m7!1e1!3m5!1srKUH2bp97u4rkVdd67koeQ!2e0!6s%2F%2Fgeo3.ggpht.com%2Fcbk%3Fpanoid%3DrKUH2bp97u4rkVdd67koeQ%26output%3Dthumbnail%26cb_client%3Dmaps_sv.tactile.gps%26thumb%3D2%26w%3D203%26h%3D100%26yaw%3D304.40421%26pitch%3D0!7i13312!8i6656!4m2!3m1!1s0x89b7c6de5af6e45b:0xc2524522d4885d2a!6m1!1e1)

[https://www.google.com/maps/place/Washington,+DC/@38.9020455...](https://www.google.com/maps/place/Washington,+DC/@38.9020455,-77.0497812,3a,75y,34.3h,86.19t/data=!3m7!1e1!3m5!1sCC1wkbIi8pfu4KAONWQjlw!2e0!6s%2F%2Fgeo2.ggpht.com%2Fcbk%3Fpanoid%3DCC1wkbIi8pfu4KAONWQjlw%26output%3Dthumbnail%26cb_client%3Dmaps_sv.tactile.gps%26thumb%3D2%26w%3D203%26h%3D100%26yaw%3D315.16916%26pitch%3D0!7i13312!8i6656!4m2!3m1!1s0x89b7c6de5af6e45b:0xc2524522d4885d2a!6m1!1e1)

~~~
r00fus
This is pretty common in France. Every major city has like dozens of these
kinds of intersections (e.g. behind the Trocadero, around the Arc de Triomphe,
etc)

~~~
Tloewald
My recollection is that the roundabouts in Paris are free for alls (a whole
different kind of crazy, but it seems to work). I checked the satellite images
of the circle around the arc de triomphe and it seems to be as I remember.
There may be lights regulating entry into the circle, but the lanes aren't
divided. And if I recall correctly pedestrians access the middle via
underground walkway.

I just checked via Google street view and it confirms my memory.

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mixmastamyk
The question should be, what is best for this particular intersection in the
near future? The two designs have different characteristics.

My understanding is that roundabouts are best when traffic is low, when it
gets heavy they become much less efficient. Lights, while a lot of overhead in
low traffic, scale better. There's also the question of space required.

Since the UK may have too many roundabouts due to traffic growth, and the US
virtually none, they could both be building the opposite and making the right
choice.

~~~
msandford
One of the great advantages of roundabouts is that they're approximately
"fair" whereas traffic lights are not.

What I mean is that a traffic light is very arbitrary and stops people who
just barely didn't make the cutoff. Multiply that by 5, 10, or 20 traffic
lights on a journey and an extra minute at each one can add up. So people have
incentive to run the light and shave the 30 seconds or a minute. But then when
people run the light, it slows down the cross-road who has to wait extra for
the road to clear, despite it being "their turn". So then people on that side
have an incentive to run the light, because they got wrongfully cutoff by the
arbitrariness and the other jerks running the light first. Rinse and repeat
for a few cycles and it's easy to see that this is not a good situation.

Traffic circles on the other hand don't suffer from this as there isn't
arbitrariness on such a 'long' timescale. If you have to wait for a couple of
extra cars it's only a few seconds, versus a minute or so. Because it's just a
couple of seconds, people have less to lose and are more inclined to be nice.
Which ultimately means that driving is more pleasant, even if it's not as
efficient.

I also might disagree with the idea that roundabouts aren't effective at high
traffic levels.
[https://www.youtube.com/watch?v=lwHfibl1AoI](https://www.youtube.com/watch?v=lwHfibl1AoI)

~~~
jrbancel
The problem with roundabouts is starvation.

I grew up in France, which has more than 50% of the world's roundabouts. They
are everywhere.

Where I am from, there is a roundabout at the intersection of a major road and
a small road with little traffic. During rush hour, it is impossible to enter
the roundabout coming from the small road because there is a continuous flow
of cars coming from the major road. It is truly an uninterrupted flow of cars
because the cars come from another roundabout...

Before the roundabout, there was no problem because there was a light that
would be always be green for the main road expect when a car was detected on
the small road. It was optimal.

~~~
cletusw
Couldn't you just put speed bumps at the entrances to the roundabout to ensure
a gap between cars in this case?

~~~
johntb86
Why don't we put a light at the entrance to the roundabout to create a gap
between cars only when necessary?

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rwmj
There seems to be no data supporting the article's assertion that roundabouts
are being replaced by traffic lights across the UK as a whole. I'll add my own
anecdata: many more roundabouts are being built in my area of the UK. There
are also roundabouts with traffic lights.

As a driver, I much prefer roundabouts. When I'm cycling, I just prefer roads
with fewer cars and can't wait for self-driving cars, since at least they
won't be driven by idiots.

There are safer roundabout designs used in Holland:
[http://www.aviewfromthecyclepath.com/2014/05/the-best-
rounda...](http://www.aviewfromthecyclepath.com/2014/05/the-best-roundabout-
design-for-cyclists.html)

------
Sanddancer
The headline makes it sound like it's a wholesale thing, but from how the
article describes it, traffic agencies in both countries are discovering that
some intersections are more useful, safer, etc if they had a different kind of
traffic control. As information disperses, it becomes easier for engineers
from different countries to share ideas and knowledge to figure out what the
best course of action is for a certain type of intersection.

------
Someone
_" Cyclists have a demonstrably harder time with roundabouts."_

As the text acknowledges, a lot depends on the design of the roundabout. Just
last week, we got [https://bicycledutch.wordpress.com/2015/10/13/explaining-
the...](https://bicycledutch.wordpress.com/2015/10/13/explaining-the-dutch-
roundabout-abroad/), which explains the current thinking of the dutch on
roundabout design.

Also, roundabouts have become more popular, but traffic deaths certainly
haven't gone up in the Netherlands
([https://www.swov.nl/rapport/Factsheets/UK/FS_Road_fatalities...](https://www.swov.nl/rapport/Factsheets/UK/FS_Road_fatalities.pdf)).

~~~
malandrew
Really? I don't find them challenging at all. Would be even nicer is they put
a protected bike ring around the outer edge so cyclists only have to watch out
for the part they are crossing across.

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anotherevan
Comment I'd made[0] on a previous article about roundabouts and their
potential for confusion:

I live in Victoria, Australia, and we’ve had roundabouts for ages. I think
they are very good for a certain scale of road/traffic. Mostly intersections
with moderate amounts of traffic on average, and not high-speed. e.g., the
main intersections within housing estates. Having too many of them instead of
give-way signs drive you a little batty (I’m looking at you, Warrnambool)
while really heavy traffic, major intersections work better with traffic
lights.

My daughter recently got her learner license, and she has found roundabouts
one of the trickier intersections to navigate. You have to read the traffic
flow. This person about to enter on your right is going straight ahead, so
will block you entering the roundabout[1], but they have to wait for that
person coming the other way from you and going straight through, so you can
slip in the gap that creates without cutting anyone else off. As with many
things it is familiarity and practice that makes them work[2]. I think
roundabouts work very well here for the most part, and my daughter is getting
pretty good at reading the traffic. It’s not rocket science[3].

The science of roads and traffic I imagine is a surprisingly nuanced expertise
involving a lot of physics and psychology. I find when I cross over the border
to New South Wales I feel like a long-tailed cat in a room full of rocking
chairs. I eventually figured out it was because the signage was a different
distance before the intersection compared to my home state. Once I was aware I
could adapt.

[0]
[https://news.ycombinator.com/item?id=10242816](https://news.ycombinator.com/item?id=10242816)

[1] We drive on the left side of the road because Australia is in the southern
hemisphere.

[2] I bet the first traffic lights caused an uproar. “Why the hell should I
stop just because there’s a red light?!”

[3] Oh wait, actually, it is rocket science.

------
zkhalique
I think if the roundabouts were large, then in fact they would always be
superior to traffic lights. I could probably run the math on that, but the
idea is that the lights aren't sensitive to the actual flow of traffic, and
often make things backed up for no reason.

~~~
josu
But roundabouts are insensitive to where the traffic is coming from. With
light traffic, this is not a problem, but with heavy traffic, if all
directions are getting the same priority, it may hurt the entrances with more
traffic.

~~~
r00fus
In France, you see main thoroughfares have overpasses or under-passes and
signals into the roundabout that it avoids. Hard to find a map, but
essentially, it is to address your concern.

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hugh4
It's possible they're both being sensible. Roundabouts are certainly under
utilised in the US (unlike those awful four-way stop signs which are
particularly hellish for law-abiding cyclists) so putting more in is a good
move.

However, as traffic at any particular intersection increases it eventually may
make sense to replace a roundabout with a traffic light. Roundabouts can
handle large amounts of traffic, but only if they're large roundabouts -- if
you can't expand the actual road space then the traffic light is the best
move.

~~~
phire
Also, in my experience, roundabouts work best if traffic at all
entrances/exits are roughly equal (within an order of magnitude or two)

If traffic flow becomes highly unbalanced, a constant flow of cars from the
primary entrance to the primary exit can block all cars from entering the
roundabout at secondary entrances. They have to wait for a car to enter at the
primary entrance then take the secondary exit so before they can enter.

I was once stuck at a roundabout for 5min due to a sports event in a nearby
town creating a constant flow of south to north traffic, when I wanted to go
from west to east. The roundabout useally worked perfectly fine, but was
broken by the abnormal traffic.

If that intersection had traffic lights, the impact on non south-north traffic
would have been minimal.

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vermontdevil
Wow I can't even. I live in Carmel, IN - basically the roundabout capital of
USA. We just built our 100th roundabout and have several more near completion.
Love them. Far better than traffic lights.

So weird to see the reason we have them is due to our Mayor visiting England
many years ago. Now they are going the other way. Did their mayor or someone
visit us and fell in love with traffic lights?

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malandrew
Strange. I rode the entire PBP (1200km) last month in France and many of the
intersections were roundabouts. I didn't see them as any better or worse for
cyclists than the 4 way intersections we have today. If anything, it makes it
easier for a cyclist to be on the lookout for where a car that could hit them
is coming from.

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dynomight
I tend to hate roundabouts. They're terrifying. But for 5-ways (and more) I
think they can be a better solution than the complicated signage and striping
of a traditional intersection. Provided that they are low speed.

There should be a compass marking at the center of each roundabout as
standard.

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shocks
Here is a particularly terrifying roundabout:
[https://www.google.co.uk/maps/@51.5628134,-1.7714704,177m/da...](https://www.google.co.uk/maps/@51.5628134,-1.7714704,177m/data=!3m1!1e3)

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bitwize
O hai. Welcome to Massachusetts, where the roundabouts have traffic lights,
and getting from the Tufts campus to downtown Somerville becomes a game of
multidimensional live-action Frogger. And that's if you HAVE a walk signal.

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chrismealy
Dutch roundabouts are the best. Lots of videos here:

[https://bicycledutch.wordpress.com/tag/roundabout/](https://bicycledutch.wordpress.com/tag/roundabout/)

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sremani
The overuse of roundabouts is US is in Bend OR. For some reason, I have seen
at least half-a-dozen roundabouts there. Most cities, I visited in US have at
most a couple of them. Bend OR is roundabout-ville.

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ck2
My town put in a few roundabouts last year and I already noticed memorial
flowers at one of them, not sure if for pedestrian, bicycle or car.

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stormcrowsx
I could see roundabouts being an advantage on smaller one or two lane streets
but beyond that it seems like it would get dangerous fast.

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andrewchambers
Why not have a roundabout with traffic lights on the entrances which are
turned on at peak times only to ensure even flow.

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ctstover
I fucking hate roundabouts.

There. I feel better now. Thanks.

Wait, no the rage is coming back - multi-lanes!!! ahhh!! help!

