http://www.wimp.com/testroundabout/
Which is more efficient? Only watch it if you are bored, as the result is as expected.
very interesting
I assume (hope) that our roundabouts are designed by mathematicians.
One problem is velocity. If drivers go round too quickly, they prevent new entrants
I have tried roundabouting very slowly and suspect that it increases the traffic flow.
Maybe
when I first went to RSA it was only stop streets, now they have circles, as they call them aswell, only problem is 80% of drivers still treat them as stop streets, makes it interesting
Dunno but at least in the states you can turn left at a red light if it’s clear, common sense.
Can’t stand lights on empty roundabouts at 3am. Be 40 grand richer without then yokes.
Silver_Surfer:
Dunno but at least in the states you can turn left at a red light if it’s clear, common sense.Can’t stand lights on empty roundabouts at 3am. Be 40 grand richer without then yokes.
Think it would be a right turn on red !
Roundabouts are fine until you add traffic lights, pedestrian crossings, stupid cut throughs etc.
yeah traffic lights on a roundabout defeats the entire purpose of a roundabout.
jobseeker:
yeah traffic lights on a roundabout defeats the entire purpose of a roundabout.
Should of had you as my brief! 
Was gonna hire that nick Hancock fellow or whatever his name was but thought i’d chance it with the local buffoon… 
Silver_Surfer, yes you can turn right on red if its not posted with restrictions i.e. school hrs and the 4 way stop works pretty well as everyone notes who was there before them, traffic runs smoothly.
Ray
I’d quite like to see 4 ways here as well although could you imagine the first one to go in? Chaos.
Silver_Surfer:
Can’t stand lights on empty roundabouts at 3am. Be 40 grand richer without then yokes.
people actually stop at those? 
maga, yes surprisingly enough they do but the highway driving is a different kettle of fish, atrocially bad.
Ray
The myth busters lot forgot to factor in the issue of priorities in just comparing the usual theoretical way that a roundabout ( would work ) if there were none in a similar way to how the four way stop works.When that issue is taken into account the four way stop idea is much better because no direction has any actual priority over another.
The idea of needing lights on a roundabout just proves the fact that they don’t work if/when there’s an inbalance in traffic levels at any particular point that’s entering them.IE if there’s too much traffic on a roundabout from one particular point that has the priority then that blocks the others waiting to enter/cross at other points hence the need for lights to switch the priorities around.
In which case all you’ve done is to turn what would probably be a quicker non light controlled junction in which no one has the priority,into one where certain directions have priority over others.Which is why in anything other than ideal conditions most roundabout or light controlled junctions end up with tailbacks on at least one or more entry points.
Having said that roundabouts do/did work better when the priority is with entering traffic not with traffic that’s on the roundabout as was the case in at least France before they reversed the idea for some reason.
Hi guys. Thought I’d do my first post on a good technical point!
The initial point to remember is the main rule of the road. I.e. Give way to the right.
For UK this works a treat as you must give way to traffic already on the roundabout.
For all the rest it’s the traffic on the roundabout that must give way to traffic entering the junction.
Only signage (including lights as they are signals) changes this. Once the entering traffic must give way the initial problem is overcome.
A combination of Road speed and roundabout size, allowing increased speed on the roundabout, and growing traffic volumes, and lack of separation, are proving the need for control of entry onto the roundabout itself.
In the U.S. case of the four way stop, this works fine until people become impatient in high traffic volumes. it only takes a few people to go out of turn and the junction becomes static and requires “manual intervention”.
In my experience the German/Dutch/Benelux system of Traffic lights that are returned to normal traffic rules out of busy periods are about the best solution. Good control when its most needed and no daft sitting around when its quiet.
What do you think?
4 ways work pretty well where I live and in most of the other places I,ve been to, you may get the odd one here and there who gets impatient.
Ray
4 way stops are the biggest waste of time and fuel ever invented, stopping and looking at what is most of the time an empty view is ridiculous, when some of these idiots stop and carefully look in each direction for about 20 seconds, then slowly start to move off, then each idiot takes there turn and you are stuck behind someone it can take a minute or more to get through one, on the other hand these people have no idea how to negotiate a roundabout 
They will stop halfway round and stare down the adjoining road to see if anything is coming, there is one particular roundabout in Hudson Falls NY, just down the road where the idiots stop half way and stare down the road to the right, instead of just going round in the left lane and merging right. I actually wrote to the local paper to voice my opinion and get hate mail.
Carryfast, I’m not disagreeing but just a question, if the vehicles joining the roundabout have priority, in busy times doesn’t the roundabout just get chocca ?
Pat Hasler:
4 way stops are the biggest waste of time and fuel ever invented, stopping and looking at what is most of the time an empty view is ridiculous, when some of these idiots stop and carefully look in each direction for about 20 seconds, then slowly start to move off, then each idiot takes there turn and you are stuck behind someone it can take a minute or more to get through one, on the other hand these people have no idea how to negotiate a roundabout
■■■■ me you’re a bundle of fun at times 
4 way stops are fine ,great traffic management in fact , can’t somehow see them working in Britain but in the ultra polite frozen North they work well .
Enjoy your week Pat
neilg14:
Carryfast, I’m not disagreeing but just a question, if the vehicles joining the roundabout have priority, in busy times doesn’t the roundabout just get chocca ?
Usually if/when traffic levels reach the point where they would block a priority to entering traffic type they’d also block a priority to traffic on the roundabout type anyway.Which is why in either case it takes traffic lights to sort out that issue.In practice,in most cases involving ordinary traffic levels,of the type found in France and Italy,where the former system was mostly used,the priority to entering traffic system combines the best aspects of the traffic light controlled roundabout system with the better flow of the roundabout system.Because it does a similar job as having lights on the roundabout but without needing lights to stop the traffic entering and on the roundabout.Whereas giving way to traffic on a roundabout just often clogs up some or all of the roads entering it.The ideal system would be remove traffic lights and remove all priorities making roundabouts a compulsory zip merge system which would then optimise the flow advantages of the roundabout system.