This is just wrong! (Care to comment, Ray? :)

[Alex Franke]

This has got to the craziest, most confusing traffic pattern I've ever seen. This so-called "magic roundabout" in Swindon, England is basically a two-way traffic circle with five one-way traffic circles nested in it. Huh?!?

Anyone here ever been on it? (You live anywhere around there, Ray?) Is it a death trap or does it just look like one? Google Maps satellite view here.


Linky: http://en.wikipedia.org/wiki/Magic_Roundabout_(Swindon)

[Uncle Cracker]

My thinking is that it would be so confusing that nobody would dare go through it at anything more than a dead crawl, so maybe it's actually safer...

[sparkeyjames]

I think maybe if we reversed all the arrows it would make more sense to us US drivers. Everything there just looks wrong because those crazy Brits drive on the wrong side of the road.

[Uncle Cracker]

...those crazy Brits drive on the wrong side of the road.

So would I... Driving on the correct side will get you killed over there...

[sweensdv]

I think it depends on how large the roundabout is. We have them around here, albeit smallish ones, but once those who shouldn't have a drivers license in the first place learn to yield to vehicles already in the circle, they actually work quite well. Without having to always stop at a Stop Sign they actually move traffic quite efficiently.

[cabinetman]

I'm trying to imagine visiting the UK for the first time (LOML did last year). Get off the plane from the US, rent a car, and drive through that intersection.
.

[Rich P]

I have actually driven through the beast back in the early 80's. I was based in Brussels but the company had a large plant and R&D facility in Swindon and I used to make the trip every few months. I would pick up duty free cigars for a bloke who worked in Swindon and he would pick up a bottle of Beefeaters whenever he flew over to Brussels.

IIRC, it wasn't too bad especially since I'd had some time on the M4 from Heathrow to get acclimated to left hand driving. The tricky part is that the roundabout (aka traffic circle) yielding protocol in the UK is sort of backwards from the continent. You yield to the right which means if you are in the circle in the UK you have right of way...just the opposite from Europe....or is the the other way round????

[jking]

This must be a very large roundabout. The traffic pattern actually makes some sense to me.

The town I live in is seriously considering putting in a small roundabout in my neighborhood. They want to slow traffic down & make the intersection safer. There is quite a bit of foot traffic; a roundabout would seem to be very unfriendly to pedestrians.

[RayintheUK]

Here's an idealised animation of the theory behind the gyratory system.

Here's one view of it in action, albeit taken from a static point.

Here, two visitors (from Finland) try their hand at negotiating it - successfully.

In practice, it's nowhere near as bad as it looks, provided you've got a good idea of where you're going before you dive in. The schematic on the approach roads is clear, as is the signposting once on the system, it's just that - for many - it's the first time they've encountered anything like it!

It's basically a development of the Scilly Isles (silly isles) at Kingston-upon-Thames in Surrey, UK. Click here, then click on the relevant link to open in Google Earth. HTH

Ray

[LCHIEN]

I think the idea of a roundabout is that you yield to traffic already in the roundabout so that works for left or right handed driving.

In practice I think the roundabout has many things to recommend it.
1. No reliance on Traffic lights - no technical complexity, works even during power failures, no utility costs, low maintenance, no bulbs to burn out
2. Very green - during less busy hours no idleing/waiting at red lights when there's no traffic, no utility costs
3. Rolling merges; You seldom come to complete stops which saves more fuel

from what I've seen in light, moderate and heavy traffic they work smoothly and well. They do make a mess when roads leading away are backed up and cars can't exit the circle.... but that also causes gridlock in traffic light controlled intersections as well.

A down side is that they take up room, its hard to put them in an existing square corner intersection. Mostly in Europe they tend to be at junctions of major roads that go between towns, cities or centers or squares or plazas.

They also tend to be at intersections of two and often three major and minor roads again because they are not used in rectanular grid road layouts.

[JR]

A down side is that they take up room, its hard to put them in an existing square corner intersection. Mostly in Europe they tend to be at junctions of major roads that go between towns, cities or centers or squares or plazas.

They also tend to be at intersections of two and often three major and minor roads again because they are not used in rectanular grid road layouts.

Not in Britain! They put a spot down at every intersection and call it a roundabout. They're coocoo for cocoapuffs over the idea.

JR

[JoeyGee]

We have one roundabout in our area and we are getting 2 more in the future. I initially didn't like the idea, but I am actually looking forward to them now.

[RayintheUK]

Not in Britain! They put a spot down at every intersection and call it a roundabout.

John, I've told you a million times not to exaggerate!

We do tend to favor what we call "mini roundabouts" because most drivers over here are so bloody-minded that they simply won't let people out at a junction into the main flow. They take up very little real estate, but work well. Here's a conventional roundabout involving three directions on the outskirts of my city:



A similar layout, again with three directions, but with a mini roundabout, used in the restricted space to good effect:



Each to their own. You have filter right on red, we have "mini gyratory" systems. Our's sounds much more posh!

Ray

[chopnhack]

They would work even better if we had some way of synchronizing cars to keep a certain distance at various speeds.... then we could have roundabouts everywhere!

[phi1l]

These things are starting to pop up around here like weeds, mostly where a normal intersection had been working fine. I think their primary purpose around here is to inflate the road building budget, & try to impede the smooth flow of traffic.