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Safety benefits of roundabouts

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Re: Safety benefits of roundabouts

#321

Post by KaiserPro »

walthamstow wrote: post #312
KaiserPro wrote: post #41

Earlier quoted context omitted.

It certainly has some protection: https://www.youtube.com/watch?v=xTk_kPeA63c (turn the sound off, its just road noise) This is what happens when you go full bore into a big roundabout. This kind of roundabout is used to join one large road to one or more small road (think two lanes going from 6-12 on the clock, with single lane road at 3 & 9) In the UK, we don't normally have stop signs, as most junctions have clear…

> Just don't look up the magic roundabout, thats just fucking batshit, we only have one. The reason why they keep it is because there is literally nothing else interesting about the place. Hemel, Swindon or England itself?

I was under the mistaken impression that Swindon was the only place mad enough to have magic roundabout, now I learn that H. Hempstead of Hertfordshire has one as well. bloody new town with their fancy town planners.

Re: Safety benefits of roundabouts

#322

Post by sfn42 »

globular-toast wrote: post #300
sfn42 wrote: post #278

Earlier quoted context omitted.

It's not a big problem to be in the wrong lane. You just change lanes like any other road. And like any other road, when you change lanes, it's your responsibility to make sure the lane you're merging into has space for you.

Perhaps you've never driven so I'll give you the benefit of the doubt. Cars can't move sideways. To change lane you have to go forwards. There is no "just change lane". Of course you could just not change lane, to the wrong way and safely correct your course later. This is preferable but people tend to get stressed out in those situations which is also bad for safety. Not to mention that a safe but ineffective road h…

Oh yeah I was totally suggesting that you should stop the car, turn all 4 wheels 90 degrees and drive sideways into the next lane. That is exactly what I was suggesting. /s

I won't bother trying to expand on my comment to you, you're clearly not someone I'll be able to communicate comfortably with.

Re: Safety benefits of roundabouts

#323

Post by bheadmaster »

One thing I love about roundabouts is the efficiency of the algorithm, compared to the classic semaphore-controlled crossroads.

Since the inbound cars are required to yield to cars that are already inside the roundabout, the cars inside the roundabout are always guaranteed to exit the roundabout in a reasonable amount of time (assuming the exit lanes are not blocked), which means that there will always be new empty spaces for inbound cars to enter in an opportunistic way.

It feels kinda like Ethernet for traffic.

Re: Safety benefits of roundabouts

#324

Post by philwelch »

ClumsyPilot wrote: post #304
kubb wrote: post #227

Earlier quoted context omitted.

Underpasses completely solve it. For small, low-traffic roundabouts, you just need pedestrian crossings like on a normal intersection, preferably with an isle between the opposing traffic lanes.

underpasses should be built for cars, not people. I have recently tried navigating the world, temporarily, with a mobility imparement, and boy does it change your perspective on things. Why do I, as a pedestrian, have to go down and then back up, why is the guy sitting in a box with 200 horsepower not the one going up and down? Also car underpasses do not become a public toilet the way pedestrian ones do Why are able…

> Why does a train station in the middle of a spacious suburb have no elevator, no ramp, and no way to get out if your can't use stairs?

As an American it’s often surprising to me how many countries lack any analog to the Americans with Disabilities Act.

Re: Safety benefits of roundabouts

#325

Post by mcv »

mrtksn wrote: post #316
pbmonster wrote: post #307

Earlier quoted context omitted.

How is that a thing? Why not just have a two-lane roundabout with the third lane skipping the roundabout and going to the next exit directly?

According to this video[0], it reduces the fight for space. IIUC, the idea is that this structure allows the flow to avoid the pile ups because you have more than one way to do something and if the one way is too busy you can take the other. Imagine a single roundabout with large number of lanes that can go just one way or exit the roundabout, then you can easily have a pile up in one exit block the drivers haded to…

I don't know, those images of cars standing still on the roundabout are not very convincing that this is an efficient way to do it. I'd love to see this compared to the more structured Dutch turbo-roundabouts: before you enter the roundabout, you pick the lane for your exit, and you just follow that. You only cross other traffic once, on entering the roundabout. After that, it's smooth sailing to your exit.

Re: Safety benefits of roundabouts

#326

Post by TedHerman »

Allow me to explain why at least one of them is so annoying. The roundabout is atop a hill; there is little visibility of what traffic is approaching from other directions because the hill is steep. Motorists don't bother signaling how far around they will go. I, riding a bicycle on a sidewalk, wish to go straight across the road. However I can't always see that someone is entering the circle. And even if I do see someone is entering, I don't know when they will exit. Compare this to an ordinary stop-signed intersection, where it is clear when vehicles are not turning and I can directly cross.

Re: Safety benefits of roundabouts

#327

Post by pbmonster »

kdmccormick wrote: post #209
adgjlsfhk1 wrote: post #203

Earlier quoted context omitted.

The lack of lights and increase in number of crossings (for non-tiny ones) make them pretty terrible to cross as a pedestrian.

(Warning: Anecdata) There was a multi-lane roundabout near me with traffic signals and pedestrian crossing signals and all. It was an absolute nightmare to drive through, bike through, or cross on foot. Cars pressured one another to drive aggressively, pedestrians had to wait for walk signals, cars got confused and blew through the crosswalks by accident even when pedestrians had walk signals, bikes were an afterthou…

> As a pedestrian, I love it because I don't have to wait for a walk signal... I just cross, and entering traffic is obligated to yield to me.

Not only entering traffic, also traffic leaving the roundabout.

Which means this only works for low traffic intersections, since a single a busy pedestrian crossing can dead-lock the entire roundabout in all directions.

My city has a slight modification of this: the pedestrian crossings are about 3 car lengths away from the roundabout. This means crossing the road takes slightly longer for pedestrians here, but the round about has a "buffer" of three cars that can wait for pedestrians before the round-about starts locking up.

But really, for busy roundabouts, pedestrian overpasses are the only sane choice. Ugly as hell to look at, but easily more comfortable than underpasses.

Re: Safety benefits of roundabouts

#328

Post by brynx97 »

gambiting wrote: post #229
adgjlsfhk1 wrote: post #203

Earlier quoted context omitted.

The lack of lights and increase in number of crossings (for non-tiny ones) make them pretty terrible to cross as a pedestrian.

Having lived in Poland for a long time - there's no issue mixing roundabouts and pedestrians, if anything they make is super easy - every exit has its own zebra crossing which means people exiting the roundabout have to stop to let you cross, which actually works well with the inherent design of the roundabout, or for really large ones with multiple lanes you just have lights.

As an American living in Krakow for the last 15 months, Poland has near universal respect for pedestrian right of way. If there is even the possibility that a pedestrian needs to cross at a cross-walk, cars will slow and stop. In the US, this would never happen. When new Americans come through, we have to tell them very plainly they must stop for pedestrians everywhere, it is sacred that you let them cross. There are a lot of other related things, but in general, Poland in my mind places people above cars, so pedestrians are much safer walking around. The US could benefit greatly with this change in attitude, but I feel there is too much road rage and selfishness to accomodate this mindset on the road.

Re: Safety benefits of roundabouts

#329

Post by darkclouds »

sfn42 wrote: post #240
kdmccormick wrote: post #209

Earlier quoted context omitted.

(Warning: Anecdata) There was a multi-lane roundabout near me with traffic signals and pedestrian crossing signals and all. It was an absolute nightmare to drive through, bike through, or cross on foot. Cars pressured one another to drive aggressively, pedestrians had to wait for walk signals, cars got confused and blew through the crosswalks by accident even when pedestrians had walk signals, bikes were an afterthou…

I never walk out in front of cars until I have made sure they see me. You never know what's going on with that driver.

I make sure they stop before stepping out in front of them. Here in the UK we have zebra black and white crossings, and the rule is (as I've been told) cars dont have to stop until your foot is on the crossing, so I stand by the crossing with one foot on the crossing, one foot on the pavement until they stop.

Anyway even crossing on these will see cars driving over them and I've been hit by cars on these crossings. I've been in cars where the driver has ignored the red traffic light at a pedestrian crossing, in fact the same one on the way to watch a film at a cinema and the same one on the way back.

The drivers problem was inexperience, and too interested in what the other passengers were saying, they wanted to join in the conversation and not pay attention to the road, and there are a lot of people whose attention dangerously fails when driving when they have passengers, but its not illegal, but using a hands free mobile phone is. Legislators and the Police are hypocrits!

That driver who ran two red lights at a pedestrian crossing got away with it because they were son of a British Police officer, Detective iirc, even though the pedestrian had to jump out of the way to avoid being hit.

Re: Safety benefits of roundabouts

#330

Post by datavirtue »

bheadmaster wrote: post #323

One thing I love about roundabouts is the efficiency of the algorithm, compared to the classic semaphore-controlled crossroads. Since the inbound cars are required to yield to cars that are already inside the roundabout, the cars inside the roundabout are always guaranteed to exit the roundabout in a reasonable amount of time (assuming the exit lanes are not blocked), which means that there will always be new empty s…

Adorable. Where I live people stop in the roundabout when they see other cars coming or they stop at the roundabout if they see any car approaching. People just don't get it.
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