USA TODAY article about roundabouts

[JNA]

http://www.usatoday.com/news/nation/2010-06-23-roundabouts_N.htm

HEADLINE: States embrace roundabouts for intersections
HIGHLIGHTS:

The biggest obstacle for roundabouts can be public acceptance, at least initially, experts say.

Drivers are conditioned that drivers on the right have the right of way, but in a roundabout, it's the other way around," Khattak says.

That's one of the big differences between what traffic engineers call the "modern" roundabout and the much-maligned traffic circles in New Jersey.

Altevogt says traditional traffic circles are large, high-speed interchanges where vehicles in the circle must yield to those entering the circle, which makes them prone to congestion. Roundabouts, on the other hand, are smaller, have slower speeds and make entering vehicles yield to those already in the roundabout, he says.

106 Comments.

Does your fair city have a roundabout ? No
What has been your experience ? Have not

 

[mgk920]

WisDOT is going whole-hog on roundabouts and now requires that they be included as an option in any study that shows that an intersection involved in a state highway project would otherwise rate either an all-way STOP signs or signals.

Example, the forthcoming US 41 major upgrades in the Green Bay, WI area (upgrading the freeway from four to six through lanes through the metro area) includes 24(!) roundabouts and *zero* signals on the surface street intersections, including interchange ramp/surface street intersections, that are modified by the project. The now-under way US 41 upgrades through Oshkosh, WI (also upgrading from four to six through lanes) includes a total of 16 roundabouts and a small handful of signals.

MANY counties and munis statewide are also on the bandwagon.

As for how well they are working - so far so good, IMHO. In many/most of the instances, the roundabouts have proven to be the ideal solutions for the intersections where they they have been used.
Case in point - the new College Ave bridge over the Fox River here in Appleton (a WisDOT project). The former two-lane high-level bridge, built in 1960, had a conventional signalized intersection just off of its east end where the street from the bridge branched into three major streets, all of which diverged at odd angles. There were ALWAYS at least signal delays getting through that intersection, even at 0200 on a Monday morning. A few years ago, it was decided to replace the worn-out bridge with a new four-lane structure and that intersection (College Ave/John St/Walter Ave) was studied. The engineers looked at several options, including a conventional signalized intersection and a two-lane roundabout. The final decision to go with the roundabout included an engineers' finding that the conventional intersection would have required the taking of six additional houses, cost over $500K more than the roundabout and would have had persistent safety problems.

The wisdom of that decision was clear from the instant that the new bridge opened in late 2009. There are very few traffic delays at the roundabout, even at commuter drive times (I have to wait for a conflicting vehicle about one out of every five times that I have driven through it so far), and I have heard zero whining from the public about it.

YMMV, of course.

Mike

 

[b3nr]

Roundabouts are cheap(ish) and they work, they take up less land, they're safer.
Roundabout time!

My only personal issue is they make the engineers lazy, when confronted with a problem, they forget everything they ever knew about grade separation and throw roundabouts at it until its solved. But then they are cheap.

Can you count how many in this picture?

 

[Raf]

Roundabouts are cheap(ish)...But then they are cheap.

Roundabouts are not cheap. Their cost here in the states can be 4X the amount that it takes to instal stop signs (signals are a different story). If a roundabout is proposed to be installed in an already built enviornment, costs may skyrocket due to ROW take and compensation. With that said, roundabouts rock. I love them. But most residents hate them (unfamilarity with them mainly). I swear, it is always the same argument against them: pedestrian safety, trucks can't get through blah blah blah. I used to show a demo video of a Sacramento RT bus going through them as a way to say, "if a bus can do it, you can too"

 

[JusticeZero]

We have one here. I like it, but it terrifies everyone else. There are often delays on it as cars stop at the entrance to it out of sheer confusion.

 

[DetroitPlanner]

A Roundabout can be cheap, but a traffic circle can cost quite a bit if it is elaborate. I would agree that the ROW costs can be astronomical because most of these corners are also great for retail.

Over time however the operational costs are much less with a roundabout because they remove complicated signals that need to be maintained else all hell breaks loose. Another factor can be that the types of crashes associated with roundabouts are less severe than they are with intersections. An intersection crash will most likely be a rear-end or T-bone causing huge medical costs while a roundabout or traffic circle may be a side-swipe which are not as medically damaging to drivers or passengers.

My first roundabouts were in Ireland. I welcomed them being that they were much easier to navigate than the standard interchange, particularly for those who are used to left hand drive instead of right hand drive. The metro Detroit area now has a few dozen of them, most are performing well. The really odd one is at US-23 at Lee Road in Livingston County. US-23 is a freeway and roundabouts are located at the top of the ramps. To the west there is a second immediate round about and to the east there are a few within the development!

 

[JimPlans]

In Massachusetts, unless the rotary (as we called them) was specifically marked otherwise, entering traffic always had to yield to traffic within the rotary. As I grew up very close to Boston, I learned how to drive on rotaries from a young age and have always though they were a logical way to move traffic.

As this website says, "[a]ccording to the driver manual, "When you approach a rotary (traffic circle), you must yield the right-of-way to any vehicles already in the rotary. If traffic is heavy in the circle, stop at the edge of the rotary and wait until you can safely enter. Only a few states in the U.S. have traffic rotaries, and as a result, many drivers are not familiar with the right-of-way rules. Be especially careful and generous when extending the right-of-way to other drivers." In practice, older cars in worse condition than yours, and other drivers who fail to make eye contact, always have the right of way in a rotary." Indeed.

 

[ajaynejr]

When yield signs are posted at roundabout entrances and at all other places where traffic merges, then there is no ambiguity with the general rule that traffic approaching from the right has the right of way.

New Hampshire has many traffic circles that do not conform with the guidelines for "roundabouts" and where right of way, with yield signs posted, varies from one entrance to another.

A major problem with roundabouts is where there are two or more lanes in the circle and it is not clear which lane must exit and/or which lane must continue around the circle. This problem can be cleared up by mandating lane dividing lines throughout the circle.

 

[mgk920]

The biggest problem that I have seen with regards to roundabouts here in NE Wisconsin involves their learning curve - quite a few people still seem to have a hard time realizing that those red things at their entrances are YIELD signs and not STOP signs. If there is no conflicting traffic in the circle, you keep going, slowing only enough to safely make the turns.

:r:

Mike

 

[Pragmatic Idealist]

I love roundabouts and traffic circles, myself. I've always wondered why the United States seems so deficient in them.

 

[Gotta Speakup]

These are extremely annoying for pedestrians. They result in you having to cross more streets or walk firther to get through them. Or so it seems.

 

[DetroitPlanner]

I love roundabouts and traffic circles, myself. I've always wondered why the United States seems so deficient in them.

Unfortunately we're deficient in a lot of things transportation-related that would make sense. In the 1950s through the early 80's the push was for interstates. Since then, the push has been for maintaining that infrastructure without looking for ways to improve it other than widening.

Lately the push has been to reduce taxes, and since your average Joe does not realize they are not taxed by a percentage of gas costs, but rather by the gallon, the mechanism for funding transportation is seriously broke. As cars get more efficient people buy less gas, thereby meaning less revenue per vehicle, but people still want to move, and that movement is still generally out, meaning longer commutes and more stress on the transportation network.

Looking at intersections and applying these ideas is a good start, but much more needs to be done.

 

[mgk920]

Unfortunately we're deficient in a lot of things transportation-related that would make sense. In the 1950s through the early 80's the push was for interstates. Since then, the push has been for maintaining that infrastructure without looking for ways to improve it other than widening.

Lately the push has been to reduce taxes, and since your average Joe does not realize they are not taxed by a percentage of gas costs, but rather by the gallon, the mechanism for funding transportation is seriously broke. As cars get more efficient people buy less gas, thereby meaning less revenue per vehicle, but people still want to move, and that movement is still generally out, meaning longer commutes and more stress on the transportation network.

Looking at intersections and applying these ideas is a good start, but much more needs to be done.

I agree that the big mistake WRT using the fuel tax for financing roadworks is that it was not set up as a percentage-based tax and is thus politically unable to properly respond to inflation.

Anyways, for as long as I have been alive, there has been a pretty strong NIH ('Not Invented Here') syndrome at work in the USA - if it was not invented nor first heavily used in the USA, it MUST be inferior! :-@ 20-30 years ago, it was the conversion to graphic signs (ie, using an image of a tractor instead of the text to denote 'FARM CROSSING' on a warning sign, the red circle/slash for 'prohibited', etc - all first developed in Europe), whereas the Europeans have had little difficulty adapting USA-developed things like the RYG traffic signals, red-octagon STOP signs, red-triangle YIELD signs, etc.

Other things being held back by the NIH thing include using high-value coins in daily commerce, km/h speed limits/km distance signs (and other 'metric' measures in daily life), etc, plus another slate of images for warning and regulatory signage and improved sign design logic.

It is sometimes quite frustrating, although I am happy that roundabouts are catching on here. Besides the obvious improvements in traffic flow that they create, they also allow for much greater flexibility in intersection design and street layout than is possible with conventional intersections and traffic signals, especially at freeway interchanges with local sideroads - and they keep working whether or not the power is on!

Mike

 

[Pragmatic Idealist]

I just spoke with a planner, yesterday, who has taken a vision plan that was developed by AECOM's Vaughan Davies and is revising it to remove all the roundabouts for reasons that I question.

Is there a way I can persuade public officials to insist on the roundabouts Davies originally proposed?

 

[jmello]

Our North Carolina city has about 8 roundabouts and we just opened two more. Our city and state staff are very much in favor of them. Residents are slowly overcoming their apprehension.

 

[jass]

I find that cities with no history of roundabouts are rushing to install them, and cities that have had them for many years are rushing to remove them.

Part of that is because a good portion of the effectiveness is that people dont know what to do and slow down. Once theyve been passing the same roundabout for 10 years, caution is thrown out the window.

 

[Johio]

A roundabout should be treated and utilized as just another tool in the box of traffic engineering solutions. They don't make sense for every intersection. I spend most of my time in Pennsylvania and Ohio and there aren't a ton of them but you see them every once and a while. They only people who seem to dislike them are the same people who make it their job in life to dislike anything new or different.

 

[Linda_D]

I find that cities with no history of roundabouts are rushing to install them, and cities that have had them for many years are rushing to remove them.

Part of that is because a good portion of the effectiveness is that people dont know what to do and slow down. Once theyve been passing the same roundabout for 10 years, caution is thrown out the window.

This seems to be the exact issue in Albany, NY: Accident Increase

I absolutely detest roundabouts. In my experience, the worst roundabout (traffic circle) in WNY is at Gates Circle in the City of Buffalo. It's two lanes with 4 two-way streets plus 2 one way exiting streets and 2 one way entering streets. One of the two-way streets is a main north-south artery, Delaware Avenue, with 2 lanes in both directions. Except in the wee hours of the morning, it's an accident begging to happen.

Close behind it is the roundabout at Niagara Square in downtown Buffalo with 2 lanes plus 6 spokes, including Delaware Avenue and Niagara Street, plus bus stops. The major issue with both is speed and lack of yielding. At least this is safe because drivers don't build up as much speed coming into it.

The village of Hamburg has replaced a lot of intersections in its downtown with roundabouts in the last 3 or 4 years. They are all single lane with 4 spokes, but people still don't yield. I'm not sure if they go too fast because I now try to avoid that area of Hamburg.

Conversely, and as jass noted, places "that have had them for many years are rushing to remove them", the state DOT removed the large two lane roundabout at Athol Springs that had been there since at least the 1950s and replaced it with a real intersection with traffic lights. The problem here was speed. People would fly through the roundabout at 55-60 MPH (posted speed limit for that entire area was 45 MPH), myself included, so good luck for traffic trying to enter from the cross roads. The traffic lights aren't fun but they are safer.

 

[Streck]

I have experienced very large diameter traffic circles (as we called them in New Orleans) and very small ones in the city I am now in.

It appeared that there was less trouble navigating the larger ones, because as you approached, you knew you had to turn right and then merge as you would get on an interstate ramp.

It appears that on the smaller circles, one is distracted by the nearby traffic coming at you from the left, and also the traffic on the right that was trying to enter from the road to the right. Also, turning radius is much tighter and "drifting" while navigating can be a very big problem.

Also, as you approach a small traffic circle, if you can see the continuation of your road on the other side of the circle, you are distracted by trying to keep your eye on the road ahead!

In general, I think traffic circles should be large enough so that you cannot see the continuation of your road on the other side. This could be accomplished by trees/shrubs, fountain/statuary, masonry/stone walls, earthwork, etc.

Also, they seem to work better where you have five roads coming together that do not lend themselves well to orderly intersectional movement.

 

[Random Traffic Guy]

In general, I think traffic circles should be large enough so that you cannot see the continuation of your road on the other side. This could be accomplished by trees/shrubs, fountain/statuary, masonry/stone walls, earthwork, etc.

Good design practice at modern roundabouts calls for elevation or landscaping to block views across the roundabout. It is especially important at night and with drunk drivers, who are apt to plow straight ahead if they can see the headlights from the opposite direction of traffic.

This seems to be the exact issue in Albany, NY: Accident Increase

Interesting article from my old stomping ground. Lots of nice quotes on how the roundabouts improve traffic flow. I think the crashes are partially driver complacency (the photos made me cringe with the tailgating), possible overcapacity on some locations (maybe should have been 2-laners, the photos just seem very busy), and also the learning curve of designers. Note the difference in crash rates for state-designed roundabouts versus local ones, the state is just much further along in many cases, and they say they would design them differently today. With proper design it is very difficult to go through too fast, the yielding is another matter. But especially with 2-lane roundabouts, improper design can lead to shortest path speeds that are too high. 2-lane roundabouts are just much more difficult to design than 1-laners.