I found an article from The Telegraph (http://www.telegraph.co.uk/news/uknews/1533248/Is-this-the-end-of-the-road-for-traffic-lights.html) last night about the town of Drachten in the Netherlands removing most of their traffic lights. The idea is that replacing traffic lights with roundabouts will force drivers to be more aware of their surroundings and to take responsibility for their actions instead of depending on a traffic light.
I personally think it would be virtually impossible to do this in the U.S. since people can't even figure out who has the right of way at an all way stop when there's a car at each leg. Everyone is scared to make the first move.
It'd be a massive change in the American approach to driving, which often seems to be premised on the idea that drivers are to be presumed never to know the law nor to be trusted to do the correct thing. The former leads to the proliferation of stupid signs admonishing you about things you should already know ("Do Not Block Intersection"); the latter leads to the proliferation of annoying traffic lights and stop signs under the theory "you might have to stop, so we will make you stop every time just in case").
Certainly there's a valid debate about the adequacy of driver training in this country, but that's for another thread.
Most of the time–definitely not all–the roundabouts I've encountered in the US have worked reasonably well, with the biggest problem being people who think they don't have to signal. But I really can't ever imagine things like chained mini-roundabouts, or the Magic Roundabout in Swindon, ever working here. I find it hard to imagine mini-roundabouts catching in much at all in the US, actually–if you put one in an urban or historic area, too many drivers will just barrel through as though it were a normal intersection.
It can work, to a point. We have more car traffic in general than Europe, and certainly here in NJ, replacing signals with roundabouts would hopelessly foul everything up. In certain small towns, yes. And across the country, definitely there are more applications. Are roundabouts better than signals? They're both just tools in the traffic toolbox.
Roundabouts are not so scary as some drivers may think they are. Just be alert behind the wheel, and make sure you signal when necessary.
If they were to replace signalized intersections throughout the United States, especially in major cities, like New York City, then I would imagine that there would be significant alterations that would be taken into consideration to construct them in certain areas.
The roundabout fad in the US may slow down though with new ADA rules (at least proposed, may be in force already) that require signalized crosswalks (HAWK beacon or traditional) at multi-lane roundabouts. I've heard rumors from an employee in a transportation agency that since they would have to signalize the crosswalks, they would go with a traditional signalized intersection over a roundabout.
Quote from: Revive 755 on March 28, 2013, 10:10:10 PM
The roundabout fad in the US may slow down though with new ADA rules (at least proposed, may be in force already) that require signalized crosswalks (HAWK beacon or traditional) at multi-lane roundabouts. I've heard rumors from an employee in a transportation agency that since they would have to signalize the crosswalks, they would go with a traditional signalized intersection over a roundabout.
From what I have seen, too few people know how to use a Roundabout.
You can thank shitty drivers for the ADA rules.
I have a better idea - get the shitty drivers off the road.
In Europe they also have a system of yielding to traffic on the right at intersections. In America, we don't (unless two people arrive at a stop sign at the exact same time) - you either have the full right of way, or have to yield to everyone else. This is part of the reason we have so many all-way stops.
Quote from: vdeane on March 29, 2013, 11:27:20 AMIn Europe they also have a system of yielding to traffic on the right at intersections.
Except in Malta and Cyprus* (where it's yield-to-left for obvious reasons of driving on the correct side of the road), the UK and Ireland** (where it isn't default), and where otherwise signed by the diamond sign - which is most of the time nowadays (any main street will be prioritized)...
*no idea if they have it in Cyprus, and not 100% on Malta (I'm pretty sure I remember seeing diamond signs when I went there years ago) - UK heritage and all
**and possibly other places
The idea is certainly worth entertaining, especially in smaller towns where the ADT is low enough to justify it. Installing a roundabout instead of a traffic signal can save on costs long term.
Like Steve said, it's one tool in the toolbox. I think agencies are starting to embrace the roundabout as a logical step between 4-way stop and traffic signal.
Quote from: Revive 755 on March 28, 2013, 10:10:10 PM
The roundabout fad in the US may slow down though with new ADA rules (at least proposed, may be in force already) that require signalized crosswalks (HAWK beacon or traditional) at multi-lane roundabouts. I've heard rumors from an employee in a transportation agency that since they would have to signalize the crosswalks, they would go with a traditional signalized intersection over a roundabout.
A signal before the roundabout defeats the purpose of a roundabout... I haven't heard anything about this. It also seems somewhat unfeasible for ADA to impose a requirement on traffic operations in this way.
Quote from: Revive 755 on March 28, 2013, 10:10:10 PM
The roundabout fad in the US may slow down though with new ADA rules (at least proposed, may be in force already) that require signalized crosswalks (HAWK beacon or traditional) at multi-lane roundabouts. I've heard rumors from an employee in a transportation agency that since they would have to signalize the crosswalks, they would go with a traditional signalized intersection over a roundabout.
I don't mean to sound confrontational, but do you have a source? Having disability laws mandate traffic signals is certainly an interesting development.
Granted, it may just be ignored, like how many agencies don't install crosswalks across major arterials whenever they meet a small cross street, even though it is an intersection and unmarked crosswalks already exist (in theory).
It's not like roundabouts are new technology or anything. So I don't see how one Dutch town favoring them will bring and end to the stoplight.
Quote from: Zmapper on March 30, 2013, 03:25:43 AM
Quote from: Revive 755 on March 28, 2013, 10:10:10 PM
The roundabout fad in the US may slow down though with new ADA rules (at least proposed, may be in force already) that require signalized crosswalks (HAWK beacon or traditional) at multi-lane roundabouts. I've heard rumors from an employee in a transportation agency that since they would have to signalize the crosswalks, they would go with a traditional signalized intersection over a roundabout.
I don't mean to sound confrontational, but do you have a source? Having disability laws mandate traffic signals is certainly an interesting development.
Granted, it may just be ignored, like how many agencies don't install paint crosswalks across major arterials whenever they meet a small cross street, even though it is an intersection and unmarked crosswalks already exist (in theory by law).
FTFY, although I too would like to see the source.
The U.S. Access Board Draft Public Rights-of-Way Accessibility Guidelines (PROWAG) specify a pedestrian-actuated signal at two-lane roundabout crosswalks with pedestrian facilities. The link to the draft (released on July 26, 2011) can be found here:
http://www.access-board.gov/prowac/nprm.htm (http://www.access-board.gov/prowac/nprm.htm)
Here is an excerpt about the proposed requirements for multi-lane roundabouts:
QuoteRoundabouts
A roundabout is a circular intersection with yield control at entry, which permits a vehicle on the circulatory roadway to proceed, and with deflection of the approaching vehicle counter-clockwise around a central island (MUTCD section 1A.13). Pedestrian street crossings at roundabouts can be difficult for pedestrians who are blind or have low vision to identify because the crossings are located off to the side of the pedestrian circulation path around the street or highway. Where sidewalks are flush against the curb at roundabouts and pedestrian street crossing is not intended, a continuous and detectable edge treatment must be provided along the street side of the sidewalk at roundabouts. Detectable warning surfaces must not be used for edge treatment. Where chains, fencing, or railings are used for edge protection, the bottom edge of the treatment must be 380 millimeters (15 inches) maximum above the sidewalk to be detectable by cane.
The continuous traffic flow at roundabouts removes many of the audible cues that pedestrians who are blind use to navigate pedestrian street crossings. At roundabouts with multi-lane pedestrian street crossings, a pedestrian activated signal must be provided for each multilane segment of each crossing, including the splitter island (i.e., median island used to separate opposing directions of traffic entering and exiting a roundabout, MUTCD section 1A.13). Transportation officials who commented on the 2002 draft guidelines expressed concern that signalization of roundabouts would interfere with the flow of traffic at roundabout intersections. Pedestrian Hybrid Beacons can be used at roundabouts. See MUTCD sections 4F.01 through 4F.03. Pedestrian Hybrid Beacons are traffic signals that consist of a yellow signal centered below two horizontally aligned red signals. The signals are normally dark (i.e., not illuminated). The signals are initiated only upon pedestrian activation and can be timed to minimize the interruption of traffic. The signals cease operation after the pedestrian clears the crosswalk. When activated by a pedestrian, the following signals are displayed to drivers: a flashing yellow signal, then a steady yellow signal, then two steady red signals during the pedestrian walk interval, and then alternating flashing red signals during the pedestrian clearance interval. The following signals are displayed to pedestrians: a steady upraised hand (symbolizing DON'T WALK) when the flashing or steady yellow signal is operating, then a walking person (symbolizing WALK) when the steady red signals are operating, and then a flashing upraised hand (symbolizing DON'T WALK) when the alternating flashing red signals are operating. Transportation officials may request permission from the Federal Highway Administration to experiment with alternative signals at roundabouts (see MUTCD section 1A.10).41
A major study was released in October 2011 (5 months after the PROWAG draft) that highlights the safety benefits of a HAWK at a multilane roundabout in West Bloomfield, Michigan. The intervention rate was the basic safety measure used in the study which is essentially the percentage of time a vehicle or pedestrian would need to make an evasive maneuver to avoid a collision during a crossing. The pre-HAWK intervention rate was 8.7% for blind pedestrians. After the HAWK was installed, the intervention rate for blind pedestrians dropped to 1.7%. Even with the significant drop in intervention rate, there is still a high probability that a blind pedestrian will encounter an intervention if they were to cross the roundabout on a regular basis. For example, a blind pedestrian crossing the crosswalk once a day for 3 months would have over a 75% change of encountering an "˜intervention event' which would require the driver to make an evasive action to avoid a collision. It could be argued that HAWK installations at multilane roundabouts would do more harm than good by providing a false sense of security to blind pedestrians.
Sighted pedestrians also took part in the study and the HAWK provided no safety benefits for sighted pedestrians (they had a zero intervention rate both before and after the HAWK installation). Here is a link to the full 115 page study:
http://www.rcocweb.org/Lists/Publications/Attachments/127/HAWK%20Final%20Report%202011.pdf (http://www.rcocweb.org/Lists/Publications/Attachments/127/HAWK%20Final%20Report%202011.pdf)
What I got from the quoted material are these two things:
(1) It only applies to multi-lane roundabouts. Single-lane roundabouts may still be implemented without ped signals.
(2) It allows for multi-lane roundabouts with no crosswalks at all. So, if you want to avoid installing ped signals at a multi-lane roundabout, then just install detectable edge treatment (grass, landscaping...) around the perimeter with no gaps and no crosswalks.
I for one cannot stand roundabouts as implemented in Oregon. They are frequently too small to allow for effective movement without stopping or coming to a near-stop, and they are too infrequent that so many people do not know how to use them (drivers will come to a stop even though they had plenty of time to proceed safely).
European style roundabouts are significantly larger. The ONE roundabout we have - which is one that has been around for decades upon decades at the intersection of Glisan and 39th Avenue in Portland - that is of a proper diameter, HAS STOP SIGNS!!! (There are also bus stops located within the roundabout - nice way to block sight lines!)
Quote from: sp_redelectric on March 31, 2013, 10:56:40 AM
European style roundabouts are significantly larger. The ONE roundabout we have - which is one that has been around for decades upon decades at the intersection of Glisan and 39th Avenue in Portland - that is of a proper diameter, HAS STOP SIGNS!!! (There are also bus stops located within the roundabout - nice way to block sight lines!)
That appears to be more correctly described as a traffic circle as opposed to a roundabout.
Aren't drivers supposed to yield to pedestrians at roundabout crosswalks anyway? In Hilliard, there's a multilane roundabout which I've been through many times each as a motorist and as a pedestrian. If a pedestrian appears to be about to step out into the street, cars will stop and wait.
With multi-lane roundabouts, traffic in the adjoining lane could block the view of the pedestrian entering the crosswalk (and vice-versa).
Quote from: sp_redelectric on March 31, 2013, 10:56:40 AM
I for one cannot stand roundabouts as implemented in Oregon. They are frequently too small to allow for effective movement without stopping or coming to a near-stop, and they are too infrequent that so many people do not know how to use them (drivers will come to a stop even though they had plenty of time to proceed safely).
European style roundabouts are significantly larger. The ONE roundabout we have - which is one that has been around for decades upon decades at the intersection of Glisan and 39th Avenue in Portland - that is of a proper diameter, HAS STOP SIGNS!!! (There are also bus stops located within the roundabout - nice way to block sight lines!)
Search for roundabout vs traffic circle. Many roundabouts in Europe are quite small.
Quote from: vtk on April 01, 2013, 08:19:41 AM
Aren't drivers supposed to yield to pedestrians at roundabout crosswalks anyway? In Hilliard, there's a multilane roundabout which I've been through many times each as a motorist and as a pedestrian. If a pedestrian appears to be about to step out into the street, cars will stop and wait.
Well for one thing, drivers are supposed to yield at all crosswalks everywhere. But, more than that, I'm not quite sure whether the new guideline is for roundabouts with a crosswalk
across the circulating roadway or
approaching the circulating roadway. If it's the former, then it's not typical roundabout design anyway, and therefore wouldn't have very much effect on the spread of roundabouts. If it's the latter, then I don't see how (as jeffandnicole) suggested, traffic would block a driver's view any more than at other, traditional intersections. Since the article cites blind pedestrians' needs as the motivation for policy change, then there may something I (a seeing person) am not considering, but I really don't get how a roundabout removes sound cues
unless if the crosswalk crosses the circulating roadway.
Perhaps someone who has experience with the blind could shed some light on the topic?
Blind people use the sound cue of steady traffic flowing across an intersection one way or the other to determine which phase the signal is in, and decide whether they can cross based on that. Essentially, they revert to the old red light / green light method that sighted people are supposed to use in absence of crosswalk-specific signals.
The problem for blind people with unsignalized roundabouts is that there simply are no phases. Cars just come and go at random. Stepping into the street and hoping the cars will stop is the only choice, for both sighted and blind people – but blind people aren't as likely to successfully jump out of the way if a car fails to stop.
Quote from: vtk on April 02, 2013, 07:12:22 PM
Blind people use the sound cue of steady traffic flowing across an intersection one way or the other to determine which phase the signal is in, and decide whether they can cross based on that. Essentially, they revert to the old red light / green light method that sighted people are supposed to use in absence of crosswalk-specific signals.
The problem for blind people with unsignalized roundabouts is that there simply are no phases. Cars just come and go at random. Stepping into the street and hoping the cars will stop is the only choice, for both sighted and blind people – but blind people aren't as likely to successfully jump out of the way if a car fails to stop.
So it's basically like a mid-block crosswalk, then, except with even less of a traffic pattern. That definitely makes sense.
Can anyone speak to whether this mandate refers to crosswalks
across the circulating roadway or
approaching the circulating roadway?
I'm sure it's about crosswalks on the approaches and exits. There aren't supposed to be crosswalks across the "circulating roadway"*. And even if there were, they'd have to be from the central island to the splitter islands in order to only somewhat screw up the roundabout's operation (as opposed to completely breaking it in the other case).
I don't like the term "circulating roadway" because that implies it functions as one continuous roadway. Instead I like to think of roundabouts as very tight yield-controlled intersections of one-way pairs. You have to keep turning left at each intersection to stay on it, so it's not one continuous roadway.
Quote from: sp_redelectric on March 31, 2013, 10:56:40 AM
I for one cannot stand roundabouts as implemented in Oregon. They are frequently too small to allow for effective movement without stopping or coming to a near-stop, and they are too infrequent that so many people do not know how to use them (drivers will come to a stop even though they had plenty of time to proceed safely).
Even the ones in Bend? In my opinion, Bend uses them very well, and traffic moves more smoothly than it would if there were four way stops or lights. They still use lights on all the intersections with more than two lane roads (two lanes total, that is), at least for now (there are plans to possibly put one at Murphy Rd (2 lanes) and Business US-97 (currently 4 lanes)). They're all over, but not overused (well, maybe a little (https://maps.google.com/?ll=44.040666,-121.327584&spn=0.002263,0.004128&t=h&z=19)), and effective. I haven't had too much experience with the roundabouts in other parts of Oregon, because many of them popped up after I moved to Bend, but I like them in Bend.
Quote from: doorknob60 on April 19, 2013, 02:58:29 AMThey're all over, but not overused (well, maybe a little (https://maps.google.com/?ll=44.040666,-121.327584&spn=0.002263,0.004128&t=h&z=19)), and effective.
okay, I'll bite. what's the purpose of that one? traffic coming out of that parking lot to the northeast can make a U-turn?
I believe to meet the definition of a "roundabout" (as opposed to a "traffic circle") there's not supposed to be pedestrians on the central island at any time, so the crosswalks would be on the approaching roads, not the circulating road.
Quote from: agentsteel53 on April 19, 2013, 09:14:12 AM
Quote from: doorknob60 on April 19, 2013, 02:58:29 AMThey're all over, but not overused (well, maybe a little (https://maps.google.com/?ll=44.040666,-121.327584&spn=0.002263,0.004128&t=h&z=19)), and effective.
okay, I'll bite. what's the purpose of that one? traffic coming out of that parking lot to the northeast can make a U-turn?
That's what I thought as well...looks to be a trip over the river about half a mile to the next roundabout to head back eastward. There's two parking lots that have U-turns served by that roundabout. Assuming the road designers were trying to save mature trees in the median, the roundabout makes sense (although the ability to make eastbound U-turns does not...it could have simply been designed as a channelized U-turn).
Quote from: roadfro on April 21, 2013, 02:14:34 AM
Quote from: agentsteel53 on April 19, 2013, 09:14:12 AM
Quote from: doorknob60 on April 19, 2013, 02:58:29 AMThey're all over, but not overused (well, maybe a little (https://maps.google.com/?ll=44.040666,-121.327584&spn=0.002263,0.004128&t=h&z=19)), and effective.
okay, I'll bite. what's the purpose of that one? traffic coming out of that parking lot to the northeast can make a U-turn?
That's what I thought as well...looks to be a trip over the river about half a mile to the next roundabout to head back eastward. There's two parking lots that have U-turns served by that roundabout. Assuming the road designers were trying to save mature trees in the median, the roundabout makes sense (although the ability to make eastbound U-turns does not...it could have simply been designed as a channelized U-turn).
Yeah, that's what it's for. A lot of people use the parking lots at Farewell Bend Park, so it's certainly useful to have, but it still seems odd. And there's no reason it needs to be a full circle either (it serves no purpose for eastbound travelers). Also, maybe they use it to slow people down. The speed limit is 25 the entire stretch from Century Dr. to 3rd St., but people often go 30-35 or more, and I've seen up to 45 down the hill and across the bridge (though that's pretty sketchy) :D
We have a seemingly useless roundabout nearby as well–see link: http://goo.gl/maps/XMDov –and I have no idea why it was put there unless they plan to extend Dudley Drive further across towards Silverbrook Road. They can't extend Laurel Crest Drive because of the houses already located there. The roundabout went in a few years ago when the golf course was being constructed on land that used to be part of the Lorton Reformatory complex (a prison that belonged to the District of Columbia). I might have thought it could be useful for U-turns except the two schools located nearby seem to serve that purpose well enough.
Yeah, I assume it's like this Kansas example (http://goo.gl/maps/nHcta) (triangle variant): development is/was expected to create a third leg.