Magic Roundabout (Swindon) • Hacker News Board

Re: Magic Roundabout (Swindon)

#101

Post by mumblemumble » Thu, Jan 23, 2020, 3:06 PM UTC

jzwinck wrote: post #87

I recently cycled some of the south coast of China. Some small towns there had roundabouts which served to slow traffic down but had a different pattern than westerners are used to. They drive on the right, but people who want to turn left would do so immediately, keeping the centre island on their right side. People turning right or going straight would use the roundabout the same as westerners. I also encountered a…

Chicago has those as well. I believe you're supposed to go all the way around the central circle when making a left turn, but nobody does.

My favorite roundabout ever is a large traditional one with only two entrances/exits. Reminds me of a lot of codebases I've encountered.

Re: Magic Roundabout (Swindon)

#102

Post by Ajedi32 » Thu, Jan 23, 2020, 3:07 PM UTC

mcv wrote: post #90

zamadatix wrote: post #74

Earlier quoted context omitted.

https://www.google.com/maps/@39.9561738,-86.1623079,150a,35y... is a "standard" two lane roundabout. Roundabouts like https://www.google.com/maps/place/Minneapolis,+MN/@44.883386... are more similar to a turbo roundabout but does not force traffic out after 3 exits or less, the inner lane could be followed indefinitely.

On that second link, I don't see any roundabout at all. It looks like a regular intersection to me.

Maybe the aerial imagery is out of date? It looks like a regular intersection on the satellite view, but Google Maps has it marked as a roundabout.

Re: Magic Roundabout (Swindon)

#103

Post by wexxy » Thu, Jan 23, 2020, 3:09 PM UTC

The closest thing to this I've seen in America is a 5 points intersection, which most of just have a sign that says "keep right" or something to that effect. Might as well just say "Good Luck!"

Re: Magic Roundabout (Swindon)

#104

Post by peeters » Thu, Jan 23, 2020, 3:12 PM UTC

DanTheManPR wrote: post #64

dghughes wrote: post #55

Earlier quoted context omitted.

I don't understand how the turbo roundabout is any different than a typical two-lane roundabout. It looks like a regular two-lane roundabout from that picture in your link.

I'm not seeing the difference between this and two lane roundabouts. We have a bunch of these in the southern suburbs of Minneapolis/St Paul, and they work well even on roads with moderately high traffic. My only issue with them is that I find them somewhat scary as a pedestrian during winter. The first few times I encountered a two lane roundabout, I had some concerns about whether you had to cut across lanes to exi…

Took me a second look to see it, look at the diagram in the Wiki link. The inside lane physically becomes the outside lane at two points, meaning you don't have to cross a lane to exit like you would sometimes need to in a "normal" two-lane roundabout.

Re: Magic Roundabout (Swindon)

#105

Post by osullivj » Thu, Jan 23, 2020, 3:13 PM UTC

wexxy wrote: post #103

The closest thing to this I've seen in America is a 5 points intersection, which most of just have a sign that says "keep right" or something to that effect. Might as well just say "Good Luck!"

Columbus Circle in NYC, on the corner of the park [1]

[1] https://en.wikipedia.org/wiki/Columbus_Circle

Re: Magic Roundabout (Swindon)

#106

Post by superhuzza » Thu, Jan 23, 2020, 3:13 PM UTC

vanderZwan wrote: post #98

djaychela wrote: post #84

I first drove this back in the early 90s when I happened to be near Swindon (for some training), and a friend (who often worked in the area) had told me about it, so I deliberately went to it. Bear in mind this is pre-common-internet use era, so everything was hearsay and so on... He told me it was a 'nightmare', and 'weird' and so on. I was actually pretty underwhelmed when I drove it - it seemed really logical to m…

I wouldn't be surprised if it is safe partially because people think it's a nightmare to navigate

That's pretty much what the Wikipedia article claims, the roundabout has an "excellent safety record, since traffic moves too slowly to do serious damage in the event of a collision"

Re: Magic Roundabout (Swindon)

#107

Post by kitd » Thu, Jan 23, 2020, 3:13 PM UTC

vanderZwan wrote: post #98

djaychela wrote: post #84

I first drove this back in the early 90s when I happened to be near Swindon (for some training), and a friend (who often worked in the area) had told me about it, so I deliberately went to it. Bear in mind this is pre-common-internet use era, so everything was hearsay and so on... He told me it was a 'nightmare', and 'weird' and so on. I was actually pretty underwhelmed when I drove it - it seemed really logical to m…

I wouldn't be surprised if it is safe partially because people think it's a nightmare to navigate

Yes, that's implied by the linked article. Everyone's so terrified of it, they drive it at a crawl.

Re: Magic Roundabout (Swindon)

#108

Post by zamadatix » Thu, Jan 23, 2020, 3:16 PM UTC

Ajedi32 wrote: post #102

mcv wrote: post #90

Earlier quoted context omitted.

On that second link, I don't see any roundabout at all. It looks like a regular intersection to me.

Maybe the aerial imagery is out of date? It looks like a regular intersection on the satellite view, but Google Maps has it marked as a roundabout.

This is interesting, I seem to be getting newer aerial imagery than either of you https://i.imgur.com/tC6fsQm.jpg

Re: Magic Roundabout (Swindon)

#109

Post by kitd » Thu, Jan 23, 2020, 3:17 PM UTC

dghughes wrote: post #55

mcv wrote: post #43

A better solution for high traffic flow is the turbo roundabout[0] which is getting increasingly popular in Netherland. Before you enter the roundabout, you select the lane for the direction you want to go. You only cross traffic when entering the roundabout for the first time. After that, you simply follow your lane and it delivery you where you want to go. It looks complicated from above, but it's very simple once…

I don't understand how the turbo roundabout is any different than a typical two-lane roundabout. It looks like a regular two-lane roundabout from that picture in your link.

The lanes spiral outwards as they go round.

Re: Magic Roundabout (Swindon)

#110

Post by Robin_Message » Thu, Jan 23, 2020, 3:18 PM UTC

mcv wrote: post #60

nicktelford wrote: post #47

Earlier quoted context omitted.

That's neat. How does it handle more than 4 junctions? The Magic Roundabout was devised as a means to efficiently handle the junction of 5 or more roads.

I tried searching for that, but couldn't find a very good example. I don't see why that wouldn't work, though: just split into more lanes before you enter the roundabout. Although it appears that Dutch traffic design tries to avoid intersections with more than 4 directions. Better merge a couple of them before the intersection.

https://www.google.co.uk/maps/@51.7309167,-0.3021986,152m/da...

I grew up by this roundabout; the south exit joins to a village. Note it has 5 exits, and is slightly tweaked: there are two lanes that go off most of the exits, except the village exit has one lane and actually going off is optional. Every major entrance to the roundabout has four lanes so you get in the lane you want for the exit you want. The minor entrances have fewer lanes so you just sort of race into the lane you need.

Oh, and it has traffic lights as well.