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Safer roundabouts are replacing traffic signals (2023)

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Re: Safer roundabouts are replacing traffic signals (2023)

#61

Post by throw0101d »

josephcsible wrote: post #24

I'll like roundabouts as soon as someone comes up with a good way to fix the resource starvation problem (i.e., if there's a constant stream of traffic from your left, you'll never get a turn to go).

> I'll like roundabouts as soon as someone comes up with a good way to fix the resource starvation problem (i.e., if there's a constant stream of traffic from your left, you'll never get a turn to go).

Add traffic signals:

* https://en.wikipedia.org/wiki/Roundabout#Signalised_roundabo...

* http://www.jctconsultancy.co.uk/Consultancy/roundabouts.php

* https://assets.publishing.service.gov.uk/media/5e81b669e90e0...

If one direction dominates, you can stop it and then let the others have a turn.

Re: Safer roundabouts are replacing traffic signals (2023)

#62

Post by leapingdog »

sam_bishop wrote: post #56

I'm an American who lived in the UK for a couple of years. They have many roundabouts there, and I love them. But now I live in an American town with a few, and I've realized that there's a reason that they are less safe in the US than in the UK--besides the fact that American drivers are less familiar with them. It's a solvable problem, but not one I've heard people talk about. (Though to be clear, I'm not a traffic…

This kind of roundabout is awful for pedestrians and drivers: https://www.google.co.uk/maps/@54.5737159,-5.9326045,127m/da...

Surprise! I'm going to walk in front of you.

Re: Safer roundabouts are replacing traffic signals (2023)

#63

Post by josephcsible »

throw0101d wrote: post #61
josephcsible wrote: post #24

I'll like roundabouts as soon as someone comes up with a good way to fix the resource starvation problem (i.e., if there's a constant stream of traffic from your left, you'll never get a turn to go).

> I'll like roundabouts as soon as someone comes up with a good way to fix the resource starvation problem (i.e., if there's a constant stream of traffic from your left, you'll never get a turn to go). Add traffic signals: * https://en.wikipedia.org/wiki/Roundabout#Signalised_roundabo... * http://www.jctconsultancy.co.uk/Consultancy/roundabouts.php * https://assets.publishing.service.gov.uk/media/5e81b669e90e0... If…

Doesn't that give up a lot of the benefits of having a roundabout at all, as opposed to having a regular signal-controlled intersection?

Re: Safer roundabouts are replacing traffic signals (2023)

#64

Post by zihotki »

jchw wrote: post #3

Trying to explain how roundabouts work to someone who doesn't get them is extremely frustrating. The rules are simple, but for some reason a lot of folks are vastly overthinking it. The thing is, I like roundabouts, but I'm somehow not surprised that the metrics focus on accidents involving death or injury. I think that because people have to slow down, it must improve those metrics. But there's a particular glut of…

> Trying to explain how roundabouts work to someone who doesn't get them is extremely frustrating. The rules are simple, but for some reason a lot of folks are vastly overthinking it.

It is a skill, it requires some practice. It's similar to math in that regards. And once you learn it you'd love them.

Re: Safer roundabouts are replacing traffic signals (2023)

#65

Post by throw0101d »

josephcsible wrote: post #63
throw0101d wrote: post #61

Earlier quoted context omitted.

> I'll like roundabouts as soon as someone comes up with a good way to fix the resource starvation problem (i.e., if there's a constant stream of traffic from your left, you'll never get a turn to go). Add traffic signals: * https://en.wikipedia.org/wiki/Roundabout#Signalised_roundabo... * http://www.jctconsultancy.co.uk/Consultancy/roundabouts.php * https://assets.publishing.service.gov.uk/media/5e81b669e90e0... If…

Doesn't that give up a lot of the benefits of having a roundabout at all, as opposed to having a regular signal-controlled intersection?

> Doesn't that give up a lot of the benefits of having a roundabout at all, as opposed to having a regular signal-controlled intersection?

If congestion occurs only at "peak" time(s) (e.g., rush hour(s)) then that's when you are stop/go with signals, whereas the rest of the time the signals are set to the 'traditional' roundabout way (perhaps flashing yellow?), then it could still mean that for (say) 20 hours of the day you still have the benefits (plus also during weekends).

And even during peak time(s) you probably get reduced collision rates and collision intensities.

Re: Safer roundabouts are replacing traffic signals (2023)

#68

Post by DidYaWipe »

numbsafari wrote: post #39
DidYaWipe wrote: post #32

Earlier quoted context omitted.

Americans still can't understand the passing lane. I'm skeptical that they're going to make effective use of roundabouts (although I do believe in their merits).

The data cited in the article is based on usage by American drivers. So you can drop your skepticism, they already work. Anecdotally, they’re converting a number of intersections here in rural, Northern MN to roundabouts and they are _very_ effective at reducing fatalities and injuries.

I guess that depends on your definition of "work." Do they reduce delays? I believe (and have seen) that they can. But I've also seen traffic circles implemented with stop signs in the U.S., a failure.

But hey, I'm down for more to be built in the USA and let's give it a shot.

Re: Safer roundabouts are replacing traffic signals (2023)

#69

Post by Aloisius »

neuralRiot wrote: post #30
tooltower wrote: post #7

I didn't get from the article: are they better than all traffic signals, or signals with unprotected left turns? And what's a good vs. bad turnabout like? I have had to go through a few that feel extremely dangerous compared to having all cars stop for me. So I know I must be missing something. Edit: Also, I see a lot of comments on yield. I'm probably confused too, but how do they work when traffic is non-stop? Is t…

The thing is that a “yield” is not a “stop”, you have to match your pace to the circulating vehicles, similar as a highway “on-ramp” you don’t stop to let all the cars pass or slow down, that’s worst than speeding up and finding your space in traffic.

In California at least, the rules for entering a roundabout are to slow down when approaching, yield and prepare to stop to traffic in the roundabout and continue when there's a big enough gap in traffic to merge safely.

While in a roundabout, there's no passing permitted so you're essentially moving at the slowest vehicle's speed (which can be you). This rule can cause a problem if you're in the inner lane or a multilane roundabout and want to exit when a car is to your right when people don't choose their lanes properly when entering.

Highway merges have somewhat different rules in that you must be at or near the speed of traffic when merging instead of slowing down and you're not permitted to stop unless absolutely necessary.

Re: Safer roundabouts are replacing traffic signals (2023)

#70

Post by kibwen »

antisthenes wrote: post #67

Roundabouts are great, if they are single-lane, low speed, and have great visibility for every exit direction. As soon as you overcomplicate it, like adding lanes, lights, 5+ exits at different angles, I would bet the advantages mostly disappear.

As soon as you get into multi-lane roundabouts, they're utterly terrifying for anyone not inside the steel shell of a car.
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