Roundabouts

[Ichinisan]

Where the red and blue arrows meet is the top of the on ramp to the interstate, no different than almost every on ramp entrance in the country.

Ah. There are some like that around metro Atlanta area. That's much more expensive and complex than an intersection since it requires an elevated overpass.

 

[Ichinisan]

the only disadvantage that i can think of for a traffic circle is that if one direction develops a majority of the flow of cars, it becomes impossible for other directions to proceed because they have to yield to traffic in the circle. so a 4-way stop is less efficient (fewer cars per unit time) but can be more "fair" to the other directions of traffic in certain situations.

It's good when the side that needs more relief from traffic gets it. It would be dynamic, by the way. When traffic starts to back up at the other entrances, eventually they will need it more and they could start dominating it once someone enters -IF- it works the way you imply. It doesn't.

If one direction develops the majority of flow (counter-clockwise in USA), they can't stop someone from entering to the left of them --- and they'll have to yield to traffic in the circle. Any time one of those entering from the left or oncoming exits to the right, that's an opportunity for someone on the right to enter. So it's unlikely any side will be held up for long.

 

[NoTine42]

Roundabouts are magic

 

[MrSquished]

When I was in Cyprus a month ago roundabouts are everywhere. So much faster than 4 way lights at least. They have those too there, but plenty of roundabouts as well.

 

[feralkid]

I guess my thread title is inaccurate, I should have said "Rotaries." Interesting stuff.

No, as both my link and his point out, rotaries and roundabouts are two separate things.

 

[RLGL]

Roundabouts: I had a co-worker who would go 60 miles out of his way to avoid them.
They are great, it's the idiots that are trying to navigate them that is the issue!

 

[KillerCharlie]

After having driven a lot in Europe, I can confidently say the roundabouts in the US suck. They're too small of a radius and the entrances/exits don't blend in smoothly. You have to make a 90 degree turn to enter it. That also means adjacent entrances/exits are close together. When trying to enter, its hard to tell if other cars are going to turn off before they reach you (most people don't signal).

 

[bradly1101]

No, as both my link and his point out, rotaries and roundabouts are two separate things.

Yes, pardon my wording, that's what I meant when I said the thread title was wrong. It was intended as a thread about rotaries/traffic circles. I'm requesting a person from merry old England to chime in about the nomenclature there (I didn't really think to call them different names, and thought roundabout was a better word for the forum's international participants than what we call The Traffic Circle here near L.A., and a Rotary in Massachusetts, which I was schooled on by this thread). What I thought I saw there, referred to as a roundabout by a reporter on the continent (DW), was akin to the circle/rotary on PCH I initially was whining about.

 

[s0me0nesmind1]

I linked the Mythbusters video in my thread about roundabouts:
https://forums.anandtech.com/threads/roundabout-vs-4-way.2346361/

https://www.wimp.com/mythbusters-four-way-stop-vs-roundabout/

The roundabout in my town is the best thing ever.

1 lane. 1 rule: Yield to traffic in the circle. Whenever someone in front of me stops for no reason (treating it like a 4-way stop), I always honk the horn at them. They're defeating the whole point by stopping for no reason.

Here is my only problem with that. Americans are assholes... Well, a lot of them are... we can agree on that, right?

People will deliberately screw over someone that is trying to merge by all of a sudden being bumper to bumper with their car in front of them, hence the person trying to yield has to stop entirely. That is ultimately why we have people that just automatically stop at yield signs instead of... yielding...

 

[Ichinisan]

After having driven a lot in Europe, I can confidently say the roundabouts in the US suck. They're too small of a radius and the entrances/exits don't blend in smoothly. You have to make a 90 degree turn to enter it. That also means adjacent entrances/exits are close together. When trying to enter, its hard to tell if other cars are going to turn off before they reach you (most people don't signal).

I love the ones that you are describing. It makes people proceed cautiously and pay close attention.

 

[zinfamous]

Roundabouts are a communist plot to destroy American freedom.