221–230 of 316 posts
Features two lanes and five exits, as well as a pass-through bridge for a highway. When you drive on the highway, you don't even see it.
https://i.prcdn.co/img?regionKey=W3NBJc2RmiFQ3sgVAHxBDg%3D%3...
Earlier quoted context omitted.
They absolutely are. Even if they don't prevent all collisions, they turn T-bones into glancing hits and so save a lot of lives. The worst roundabout beats the best 4-way stop any day of the week. Sometimes there really are easy answers.
Roundabouts not good for pedestrians and cyclists. In London we’ve been replacing roundabouts with other types of junction to improve pedestrian and cyclist safety. We don’t have four way stops though so instead it’ll be min/maj junction or traffic lights.
It’s extremely common in the Netherlands to replace crossroads and T-junctions with roundabouts to improve safety, but Dutch urban roundabouts are designed with safety as the main priority. This is achieved through single lanes, sharp entries, limiting forward visibility, and pedestrian and cyclist priority (via what are effective zebras).
For more information see eg: https://bicycledutch.wordpress.com/2015/10/13/explaining-the...
(Edit: fixed wrong link)
Earlier quoted context omitted.
4-way stops are bizarre to me having grown up in the UK where roundabouts/intersections with priority given for one direction are trusted and reliable traffic-calming measures. I think one of the reasons a 4-way stop might be introduced is to improve safety where there was previously a 2-way stop (that people would blow through). I came across this in Canada recently. All I can say is the UK has drastically lower tra…
Four way stops are common in lightly trafficked situations where the locals can't justify spending the money on anything but a few stop signs. For instance, the main street through a small town ( Four way stops are also common when two country roads of relatively equal weight intersect. There are so many roads like that, so many intersections, that the local government can't possibly afford lights or circles on all o…
In Europe one road (perhaps arbitrarily) would be declared the main road, and the other road gets yield signs, or even just yield road markings (triangles).
This is oddly timely. I'm travelling in Europe at the moment and have been covering a lot of area with a lot of roundabouts where they would be signaled or signed intersections in the US. They definitely make traffic flow smoothly and I've noticed a few areas where they are used to eliminate dangerous left turns at places like parking lots, you leave turning right, hit the next roundabout to "uturn" then head back th…
> They definitely make traffic flow smoothly They make slow or medium traffic flow smoothly. If the traffic is heavy, roundabouts make everything worst.
Roundabouts get a lot of praise whenever they're mentioned, and from a traffic flow perspective that's understandable - if by traffic you mean motorised traffic. For pedestrians and cyclists they are worse than the alternative (lights - or even a simple intersection) in my opinion. > Making a roundabout for everyone ctrl-f "walk", "cycl", pedes". Nothing.
[0] https://bicycledutch.wordpress.com/2015/10/13/explaining-the...
Roundabouts get a lot of praise whenever they're mentioned, and from a traffic flow perspective that's understandable - if by traffic you mean motorised traffic. For pedestrians and cyclists they are worse than the alternative (lights - or even a simple intersection) in my opinion. > Making a roundabout for everyone ctrl-f "walk", "cycl", pedes". Nothing.
Cars turning right at an intersection are an order of magnitude more dangerous.
This is oddly timely. I'm travelling in Europe at the moment and have been covering a lot of area with a lot of roundabouts where they would be signaled or signed intersections in the US. They definitely make traffic flow smoothly and I've noticed a few areas where they are used to eliminate dangerous left turns at places like parking lots, you leave turning right, hit the next roundabout to "uturn" then head back th…
I'm living in Germany, where roundabouts are very popular with planners recently. I would say they definitely have their place, but they are also overused. The (smallish) city where I live has a bypass road where for some reason it was decided to use roundabouts (I suspect the same reason why it has so many tight curves - not wanting to purchase too much land). With the result that using the bypass is not much faster…
No discussion about roundabouts can be complete without a mention of the (mostly) Dutch "turbo roundabout", where the lane you take going into a multi-lane roundabout depends on where you want to exit, and you can't / are not allowed to switch lanes while on it: https://wiki.openstreetmap.org/wiki/Tag:roundabout%3Dturbo https://en.wikipedia.org/wiki/Roundabout#Turbo_roundabouts https://www.arcadis.com/en-us/knowledge…
This is literally just how you're supposed to go round any roundabout. Right lane if you're going straight ahead or right (to any extent), left lane otherwise. Anything else _will_ cause crashes, because vehicles will necessarily have to cut across each other to exit the roundabout. The "turbo roundabout" might make this explicit, but it's not different.
E.g. a standard 2-lane by 2-lane roundabout intersection may just as well look like this https://i.imgur.com/jqhMxW4.jpeg. Note the entrance markings allowing all lanes to go straight with 1 alternative turn direction per lane choice, the exit markings allowing dual lane exits in all directions, and internal markings allowing u-turns (the roads in this case have medians farther out). It has some of the downsides you mention but also some upsides in exchange for allowing slightly more lane flexibility. Regardless, you're definitely not supposed to follow the turbo's rules in that roundabout.
Now you could "no true Scotsman" it and say all the other roundabout types aren't roundabouts because they are supposed to be like turbo roundabouts to be so... but that still leaves needing the distinction in types, for which everyone calls one a turbo roundabout and other variations different types of roundabout.
This is oddly timely. I'm travelling in Europe at the moment and have been covering a lot of area with a lot of roundabouts where they would be signaled or signed intersections in the US. They definitely make traffic flow smoothly and I've noticed a few areas where they are used to eliminate dangerous left turns at places like parking lots, you leave turning right, hit the next roundabout to "uturn" then head back th…
We love a good roundabout in the UK, however it can be taken to extremes. The Magic Roundabout[1] in Hemel Hempstead is basically a roundabout made up of 6 mini-roundabouts. When it was first built locals used to sit in the middle watching the crashes. 1. https://en.wikipedia.org/wiki/Magic_Roundabout_(Hemel_Hempst...
Indeed, the junction in the headlined article is a slight variation on a quite common U.K. junction type: the double mini-roundabout. We can point to loads of them, such as this one in Bridgeyate (https://www.openstreetmap.org/#map=19/51.457696/-2.462268) for just one random example.
All of the WSDOT's points, about how large vehicles traverse them and how they are shaped like that because the staggered junction or slightly askew cross-roads that they replaced has space restrictions, apply to double mini-roundabouts.
And as bane said, the research in the U.K. back in the 1970s when double mini-roundabouts were a new thing showed a significant reduction in accidents over the prior staggered junctions and askew crossroads, at less cost than enlarging the junctions.
So the response is not to perplex the United Statians with Hemel Hempstead, but to welcome them to the shiny new future of 1970s road systems. And perhaps warn them that by the 1990s the road markings will have become a bit worn and scuffed by all of the HGVs driving over the centre. (-:
