We're excited about our new roundabout • Hacker News Board

Re: We're excited about our new roundabout

#281

Post by orthoxerox » Mon, Oct 07, 2024, 2:14 PM UTC

throwway120385 wrote: post #276

necrobrit wrote: post #149

Earlier quoted context omitted.

The preference for 4 way stops in a country that otherwise prioritises traffic flow so much is really jarring. Traffic lights too to some extent. About 5 years ago my wife an I were doing a California road trip. At one point on a relatively rural road -- I think it might have been Dry Creek road heading into Napa but cannae mind exactly -- we got stuck in traffic for around 45 minutes. We thought there must have been…

I like 4-way stops as a pedestrian because I can actually cross the road there. With roundabouts it's impossible to cross without asking really nicely or risking my life. US drivers do not stop for pedestrians so crossing that kind of infrastructure is often taking your life into your hands.

This can easily be solved with a camera. Not yielding to a pedestrian = instant fine.

Re: We're excited about our new roundabout

#282

Post by steelframe » Mon, Oct 07, 2024, 2:20 PM UTC

consp wrote: post #228

rob74 wrote: post #132

Earlier quoted context omitted.

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…

Sometimes roundabouts are used to limit traffic speed, since you MUST slow down, while keeping the same flow (for the calculated traffic throughput). Maybe that was the purpose. Roundabouts are generally more expensive than intersections due to needing more land works and more land than a normal cross intersection.

> since you MUST slow down

Where I live some of the locals treat a newly-built roundabout like the Daytona Speedway. It's almost as if their mentality is that you must NOT slow down, and they won't hesitate to express their displeasure at you if you happen to be "in their way" going the 15mph speed limit through the roundabout.

Re: We're excited about our new roundabout

#283

Post by vhodges » Mon, Oct 07, 2024, 2:32 PM UTC

btbuildem wrote: post #249

necrobrit wrote: post #149

Earlier quoted context omitted.

The preference for 4 way stops in a country that otherwise prioritises traffic flow so much is really jarring. Traffic lights too to some extent. About 5 years ago my wife an I were doing a California road trip. At one point on a relatively rural road -- I think it might have been Dry Creek road heading into Napa but cannae mind exactly -- we got stuck in traffic for around 45 minutes. We thought there must have been…

90% of stop signs in the US/Canada should actually be yield signs. Stop signs are reserved for "dangerous" intersections, ie spots where a driver can't safely see or make a decision without first stopping. Throwing a red octagon at every single intersection of two roads is lazy and absurd. It encourages people to break the rules (just run the stop sign) and cause accidents (zone out, stop and go without actually look…

There's a T intersection in Mission BC that has a stop sign that (for people turning right) should be a yield (at most) because to the left is a one-way after the intersection eg no one should be coming from there :) but the problem is it's single lane and people making a left there should stop.

When turning right, I and a lot of people barely bother slowing down. It's always a bit frustrating when someone does what the sign (and the law of course) says when the don't need too from a pragmatic point of view :-D.

Re: We're excited about our new roundabout

#284

Post by n4r9 » Mon, Oct 07, 2024, 2:47 PM UTC

> even our designers don’t know of any similar roundabouts this small

Mini-roundabouts are commonplace in the UK, e.g.:

https://www.google.com/maps/@51.4072632,-0.2739497,3a,29.6y,...

Re: We're excited about our new roundabout

#285

Post by gs17 » Mon, Oct 07, 2024, 3:39 PM UTC

rootusrootus wrote: post #24

Dalewyn wrote: post #20

Earlier quoted context omitted.

I'll take a traditional cross with traffic signals or stop signs on all sides, it's simple and effective. Roundabouts are a waste of space, disrupt traffic, and take more brain processing than I care to afford if I can help it. This particular example isn't even round.

I vastly prefer roundabouts, with a single exception. If traffic is heavy and dominated by the same entry and exit points, it can be hard to get a turn if you're coming from the side. Our nearest roundabout is this way. I once saw a roundabout with stop signs. I assume it was an attempt to address this situation.

I used to go to work past one like this. They replaced a light where you would always eventually get to go with a roundabout where the 99% of traffic going north/south meant the other two ways were effectively not part of the traffic network for a few hours a day.

Re: We're excited about our new roundabout

#286

Post by zamadatix » Mon, Oct 07, 2024, 3:49 PM UTC

timdiggerm wrote: post #263

zamadatix wrote: post #247

Given the amount of space if I were driving through it I'd wish they had just made it a little larger so it could be a normal "full circle" roundabout. Sometimes the biggest problems with roundabouts is the number of variations. "You can use this lane to go that way here but a mile up if you want to go that way you want to make sure you're in the other lane". Not to mention it seems somewhat easy to speed through wit…

Did you read the blog post? >The new roundabout needed to be built in the same space as the old intersection. To the east is a steep hill. To the southwest there are protected wetlands. There wasn’t space or budget to mitigate the potential impact in either direction.

I'd like to think I'm clever but I cannot claim to be able to come up with alternative shapes to intersections without first having read the blog post about what they chose :).

Budget to fix the hill yes, it's a real life thing, but one can still wish they had been able to allocate things to do it right. As far as the wetlands... https://i.imgur.com/x0WGHXa.jpeg how many lives is a small part of that narrow strip of wetlands between a farm and 2 roads worth? Easy to change? No... but the right thing to have changed? I think so. Now that they've done neither the intersection is still not very safe (IMO, time will tell) and the limited budget was consumed in doing so.

Solely focused on dealing with "what sounded like the easiest and cheapest intersection to put in" I think they did a decent job, I just wish they had been able to do more. Intersections like this not only remain unsafe but give a bad public taste to roundabouts that are able to be properly done - "Oh I HATE roundabouts, I can't ever tell when to yield or where the lanes go. I don't want one in town" when really it's just a horrific roundabout they went through.

Re: We're excited about our new roundabout

#287

Post by joecool1029 » Mon, Oct 07, 2024, 4:55 PM UTC

zamadatix wrote: post #243

ojhughes wrote: post #160

I thought Americans called them "turning circles"

Depends where and who you're talking to. Overall though, I'd say it's probably most often roundabout, traffic circle, and rotary (in that order) and I haven't heard much else. And yes, they are different things to traffic nerds, but I mean places (particularly in the NE like Massachusetts) just call them all rotaries regardless what the traffic department teaches https://www.mass.gov/info-details/what-are-roundabouts…

In NJ we have traffic circles which are larger, much higher speed, and consequentially much more dangerous. They have been re-engineering them in recent years to be more like roundabouts but it used to be you could slam around one of them doing 55mph or so without stopping or slowing much to enter (until it backed up).

https://en.m.wikipedia.org/wiki/Traffic_circles_in_New_Jerse...

Re: We're excited about our new roundabout

#288

Post by bane » Mon, Oct 07, 2024, 4:57 PM UTC

watwut wrote: post #194

bane wrote: post #108

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.

I believe that I've read that elsewhere. They allow for better and higher flow than an intersection, but have a weird failure mode at very high rates where the circle gets loaded and all directions thus stop.

Re: We're excited about our new roundabout

#289

Post by ProllyInfamous » Mon, Oct 07, 2024, 5:19 PM UTC

desas wrote: post #125

ProllyInfamous wrote: post #33

Earlier quoted context omitted.

We have back-to-back round-a-bouts in Chattanooga (153 / Lake Resort / Access) which have two loops (concentric inner & outer round-a-bouts)... that can be quite confusing for anybody unfamiliar with the local pattern.

Like the Magic Roundabout in the UK? https://www.bbc.co.uk/news/articles/cdx9nlgk97eo

I would do everything possible to avoid this UK Round-a-bout — nothing Magical about it having three concentric lanes just in its inner loop! =P

Ours is much simpler, with a round-a-bout on either side of a regional highway. One of the difficult parts about it is everybody is already jacked the fuck up (on account of 2 of the 5 input/outputs being extremely steep grade to enter/exit a river-crossing, with speeds averaging 65-70mph ["55mph" posted, oklol).

Re: We're excited about our new roundabout

#290

Post by MostlyStable » Mon, Oct 07, 2024, 5:24 PM UTC

userbinator wrote: post #103

MostlyStable wrote: post #66

Earlier quoted context omitted.

Wait until you find one of the distressingly common places where they build a roundabout and put stop signs on some or all of the entrances.

That's not a roundabout, that's a 4-way-stop with an island.

I am not sure if you are disputing that such things exist, or making a sarcastic comment, but I know of at least one location where they literally put in a round about, that originally had normal roundabout entrances, but then someone complained a dug up some rule that said that anywhere a county and a city road met, there needed to be a 4 way stop. Now obviously this rule was intended to just make sure that such intersections were controlled, and was probably written before the US had really thought about round abouts as an option and a roundabout met the spirit of the rule just fine, but nevertheless it was a rule, and so they added a stop sign at each entrance.

So, if you were making a sarcastic joke: then yup, they managed to convert a round about into a 4-way stop with a (giant, view obstructing) island. But if you were arguing that no one would do such a thing as put stop signs at the entrances to a round about, I regret to inform you that they absolutely would.

Also, I'm now curious about the existence of "4-way stop with an island". Why would someone build that? It seems strictly worse than a regular 4 way stop.