Lights at traffic circles

[brendan]

Saw this on washcycle yesterday:

http://www.youtube.com/watch?v=gVW-YAQCSVs

Link to washcycle post and too-short comment thread: http://www.thewashcycle.com/2013/04/sunday-video-removing-the-traffic-lights.html

Brendan

[DaveK]

Roundabouts definitely have challenges for cyclists and pedestrians. The knowledge on this subject is evolving all the time and the optimal designs look more like something from Europe these days. The state of the practice is to merge an on-street bike lane on an approach to a side path before getting to the roundabout, then manage the crossings around the circle well away from the circulating roadway itself, crossing the approaches. Cyclists can choose to either use this side path or merge with circulating traffic. Curbside bike lanes around the circulating roadway of a roundabout are considered a negative in current traffic engineering practice. They lead to too many right-hook incidents, since they’re not a place where drivers tend to look for cyclists.

Signals are not used in modern roundabout design. They eliminate the delay-reducing benefits of the design. The DC “traffic circles” like Dupont, Thomas, or Washington Circles don’t fit any design standard and are adaptations of a centuries-old city street plan to the realities of modern motor vehicle traffic. DDOT (the current staff anyway) doesn’t deserve the blame for the train wreck that is Dupont Circle, that starts with L’Enfant and continues to the engineers who put in traffic signals in the first place. Cyclists wouldn’t have been considered, at least not as part of the signal design. The decision was probably made back in the day when moving cars was the be-all, end-all of traffic engineering. That said, there are pedestrian improvements made to the circles regularly, in fact I think that Washington Circle is getting a makeover soon.

So after I’ve coughed up all that from my head, I’ll tell you that I ride exactly like you do. I treat the entrance approaches to the circles as a roundabout should be treated and I yield to the traffic in the circle. If I see an opening that’s safe, I’m going to take it and take my place in the center of the lane in traffic.

[GuyContinental]

@brendan 50558 wrote:

Saw this on washcycle yesterday:

Link to washcycle post and too-short comment thread: http://www.thewashcycle.com/2013/04/sunday-video-removing-the-traffic-lights.html

Brendan

Whoa… looks awesome right up until you add (insert stereoscopically bad American driver here- for me anyone in Loundon or with MD plates)

[brendan]

@DaveK 50559 wrote:

So after I’ve coughed up all that from my head, I’ll tell you that I ride exactly like you do. I treat the entrance approaches to the circles as a roundabout should be treated and I yield to the traffic in the circle. If I see an opening that’s safe, I’m going to take it and take my place in the center of the lane in traffic.

Same here. I also filter forward at the light if it seems safe to do. Safe filtering can depend on timing: if I think the light may be about to change, I’ll wait in the queue.

Brendan

[jrenaut]

I don’t get the YouTubes at work, I’ll have to check that out later.

Dave, thank you for confirming my lawlessness. I don’t take the lane there, but maybe I should start that. Partly I like to take the bike lane and assert my right of way (carefully) to try to help educate drivers.

[Steve]

I pray in my head sometimes that Memorial Circle could look like this (the elevated ped circle, not the skyscrapers). I’d imagine you feel the same way as some of the circles in DC.

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[jrenaut]

How about making the cars go underground so that plaza in the middle is welcoming and inviting rather than an island in a sea of pavement?

[Steve]

@jrenaut 50565 wrote:

How about making the cars go underground so that plaza in the middle is welcoming and inviting rather than an island in a sea of pavement?

My dreams can only get so greedy.

While that is fair, I would think building a pedestrian bridge up is more cost effective than building a road down. It certainly is less attractive, but I tend to sympathize with the fact that budget decisions are extremely hard to make, and I’ll take safe over pretty.

[DaveK]

@Steve 50570 wrote:

My dreams can only get so greedy.

While that is fair, I would think building a pedestrian bridge up is more cost effective than building a road down. It certainly is less attractive, but I tend to sympathize with the fact that budget decisions are extremely hard to make, and I’ll take safe over pretty.

More cost effective, yes, but pedestrian overpasses are terrible things for streets. People don’t use them if it’s physically possible to cross the street at grade, even if that means scaling a fence sometimes. They kill the life of a street and give drivers another visual cue that they are on an expressway, not an urban street. They really should be an absolute last resort.

[Steve]

@DaveK 50573 wrote:

More cost effective, yes, but pedestrian overpasses are terrible things for streets. People don’t use them if it’s physically possible to cross the street at grade, even if that means scaling a fence sometimes. They kill the life of a street and give drivers another visual cue that they are on an expressway, not an urban street. They really should be an absolute last resort.

Perhaps. Though I believe in the development that I pictured above, the shopping, cafes, etc., is all done at the pedestrian plaza level. I guess it partially depends on the location and what you’re trying to accomplish. Memorial Circle is a thru traffic route, not an urban street, and so separating the two grades is great IMO. Some places in DC you probably are looking for much more of a shopping/dining community area, a much more urban environment, and so I think you’d be right there in terms of hurting the street.

This is the one I was looking for earlier when I found the other. It’s clearly a bit more suburban, and so I agree that it is probably a better solution in these environments, not the urban ones necessarily.

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[vvill]

DC traffic circles are weird and scary in my experience as a driver, pedestrian and cyclist. I’ll admit I still don’t know how to drive through Dupont Circle properly.

They’re very different to the style of roundabouts I grew up with, which I have no problem with. Roundabouts to me are sort of like a more flowy version of a 4-way stop (which I was not familiar with until I moved here). I’m always happy to see more roundabouts in Arlington as I feel they’re easier to navigate through as long as drivers understand how they work. I often ride through the one near Bishop O’Connell HS (N Trinidad and N Little Falls) and it seems to work perfectly for the type/amount of traffic that goes through there.

[dasgeh]

Arlington’s relationship with roundabouts is weird. For some reason, they put circles all over neighborhood streets, but then put in stop signs for the approaches from one street.

And heaven forbid someone suggest that Clarendon Circle be a traffic circle!

[DaveK]

@dasgeh 50591 wrote:

Arlington’s relationship with roundabouts is weird. For some reason, they put circles all over neighborhood streets, but then put in stop signs for the approaches from one street.

And heaven forbid someone suggest that Clarendon Circle be a traffic circle!

I have many, many thoughts on this subject. Let’s just leave it at this: neighborhood traffic circles should not have stop signs.

[KLizotte]

I grew up in New England where we had rotaries (we didn’t call them roundabouts). Most are as badly designed as those in the DC area; one notorious one is on Rte 2 in Concord because it has two very busy lanes and drivers from the innner circle are always cutting across the outer lane without looking first if the way is clear. Rush hour there is scary.

I also lived in the UK where the majority of intersection outside of the major cities are roundabouts (without stop signs). Those generally work very well since drivers are so accustomed to them and and they are well sign-posted. Seems wasteful to spend money on expensive lights when a roundabout will do. There is a place in the UK where there are seven(!) roundabouts linked together.

That said, I’d never been to a properly designed two lane roundabout until I drove in Iceland (it was located in Reykjavik); it was at that point that I went d’oh! That’s how they are supposed to work! So simple and efficient!! I won’t try to describe it in detail except to note that if you got into the outer lane, you were forced by the infrastructure’s design to take the next exit. When entering the roundabout, you only had to worry about one lane of traffic due to this design. There were pedestrian paths all the way around the circle and I don’t recall having any problems negotiating the crosswalks as a ped. I really wish we could institute such roundabouts here. Note: these designs will only work if single lanes are feeding the roundabout but traffic is always moving so backups are minimized esp when compared to light controlled intersections.

I wish Arlington would institute a roundabout at 15th and South Hayes (by the Pentagon City Mall).

[dasgeh]

Totally agree that roundabouts only work with one lane entering and one lane exiting.

The stop signs in Arlington are not only silly, they make things more dangerous, as drivers don’t know what they mean. We just had a discussion on our neighborhood listserve between those that thought the stop signs changed the ROW in the traffic circles (so that drivers without stop signs had ROW over all others, including those u-turning or turning left in the circle before them). Ugh. If you need signs, everyone should get yield signs. Is there a shortage of yellow triangles?

[Author]

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