(https://www.aaroads.com/forum/proxy.php?request=http%3A%2F%2Fi49.tinypic.com%2F2mpbxue.jpg&hash=38b0a186590811bbf0e04178483d75b5d1653f8a)
The blue guy is not using the roundabout correctly, but there are no signs at this one telling you which lane to use.
Normally the striping would say which lane to use; maybe they're waiting for that other road to be finished to fix it.
I hate multi-lane roundabouts because of this. They should be illegal. And I would say the red guy is wrong. But that's just my opinion. I think you can exit the roundabout from the inner lane here but you have to make sure that the outer lane is clear for you to make the move.
I don't see the problem. In the absence of striping or signage to clarify, the rules of the road apply.
The rotary part must be treated as a two-lane, one-way road. Each driver is entitled to his lane. When a driver wants to turn off, which is of course always a right turn, he should do so from the right lane. If he's in the left lane, he needs to yield to right-lane traffic when leaving his lane.
This is a prime example of why you do not use concentric circles to mark the circulatory roadway or do not stripe the circulatory roadway whatsoever. So many design flaws...path overlap, long tangents connecting approaches and exits, no truck apron...must have been the first multilane roundabout of someone's design career.
Quote from: theline on April 11, 2013, 05:14:44 PM
The rotary part must be treated as a two-lane, one-way road. Each driver is entitled to his lane. When a driver wants to turn off, which is of course always a right turn, he should do so from the right lane. If he's in the left lane, he needs to yield to right-lane traffic when leaving his lane.
in the case of certain rotaries (roundabouts? traffic circles? who gives a shit) in one or two states, exiting traffic has the right of way, regardless of lane.
I think it's Rhode Island and maybe Massachusetts.
the blue guy might not be using the rotary in a manner which maximizes traffic throughput, but he isn't doing anything which is made illegal by any regulatory signage or striping. the fact that one or two states have an obscure 1930s law on the books which contradicts
every other law in the US with regard to right of way - namely, that staying within the stripes give you right of way, is one for the personal injury lawyers to be gleeful about... no one else benefits.
the Dutch "turbo roundabout" solves most of these lane issues. I think I've seen these in the US - Colorado comes to mind.
(https://upload.wikimedia.org/wikipedia/commons/thumb/e/e4/Turborotonde.svg/220px-Turborotonde.svg.png)
(I don't know why there are yield stripes on the exit splits... I think that may be a design error in the diagram.)
here's a diagram of a well-striped roundabout.
(https://www.aaroads.com/forum/proxy.php?request=http%3A%2F%2Fwww.dmv.ny.gov%2FolderDriver%2Fimages%2Fmulti-lane.png&hash=a16c715febe3ea579b316b7e90209c4c5627140f)
it eliminates the perceived "within the roundabout, traffic in right lane must yield to traffic in left lane". no, it's actually "traffic in right lane must exit, otherwise he is swept into changing into the left lane, and thus must yield to traffic already within the left lane".
In some jurisdictions neither driver "has" the right of way and instead it's a question of who is required to yield the right of way.
Hypertechnical distinction, I know.
Quote from: 1995hoo on April 11, 2013, 05:55:35 PM
In some jurisdictions neither driver "has" the right of way and instead it's a question of who is required to yield the right of way.
Hypertechnical distinction, I know.
and essentially meaningless, no? one driver "has", the other is "required to yield".
I don't think there is any legitimate situation where both drivers are "required to yield" (deadlock), or when both drivers "have" (disaster).
Quote from: DaBigE on April 11, 2013, 05:18:59 PM
This is a prime example of why you do not use concentric circles to mark the circulatory roadway or do not stripe the circulatory roadway whatsoever. So many design flaws...path overlap, long tangents connecting approaches and exits, no truck apron...must have been the first multilane roundabout of someone's design career.
Here's one near the Notre Dame campus with lane markings. It works pretty well: http://goo.gl/maps/vXn4D (http://goo.gl/maps/vXn4D). There are also guide signs on the approaches: http://goo.gl/maps/ZzSO8 (http://goo.gl/maps/ZzSO8).
Quote from: theline on April 11, 2013, 06:03:23 PM
Here's one near the Notre Dame campus with lane markings. It works pretty well: http://goo.gl/maps/vXn4D (http://goo.gl/maps/vXn4D). There are also guide signs on the approaches: http://goo.gl/maps/ZzSO8 (http://goo.gl/maps/ZzSO8).
now that's fun. at 45 degree view, there are lane markings. at straight overhead view, there are not. the overhead must be older, and they realized that it was a problem to not stripe the lanes as a "turbine".
Quote from: theline on April 11, 2013, 05:14:44 PM
I don't see the problem. In the absence of striping or signage to clarify, the rules of the road apply.
The rotary part must be treated as a two-lane, one-way road. Each driver is entitled to his lane. When a driver wants to turn off, which is of course always a right turn, he should do so from the right lane. If he's in the left lane, he needs to yield to right-lane traffic when leaving his lane.
http://www.wsdot.wa.gov/safety/roundabouts/#multi
Quote from: NE2 on April 11, 2013, 06:51:22 PM
Quote from: theline on April 11, 2013, 05:14:44 PM
I don't see the problem. In the absence of striping or signage to clarify, the rules of the road apply.
The rotary part must be treated as a two-lane, one-way road. Each driver is entitled to his lane. When a driver wants to turn off, which is of course always a right turn, he should do so from the right lane. If he's in the left lane, he needs to yield to right-lane traffic when leaving his lane.
http://www.wsdot.wa.gov/safety/roundabouts/#multi
the diagram shows a roundabout in need of some explicit turbine striping.
I think Mister Line has a very valid point - mis-striping a roundabout seems to be giving rise to contradictory laws. don't all states have a law on the books that staying in one's lane gives one right of way, and those who change lanes (i.e. cross a set of stripes) have to yield?
The Dutch got it right with their turboroundabouts:
(https://www.aaroads.com/forum/proxy.php?request=http%3A%2F%2Fi1.tinypic.com%2Fxm8k1w.jpg&hash=af2ee9e399309cc7712c47d9ac79854287de963e)
No question whatsoever about what lane goes where.
Edit: and now I see they were already mentioned. Oh well.
Using the original example, both are incorrect. If everyone followed the red line, then what use is the outer lane? If everyone followed the blue line, what use is the inner lane? I'd say the red line's path is especially dangerous, because it would either force cutting off vehicles in the right lane, or holding up continuing traffic in the left lane while they wait to exit.
I've seen pamphlets in the Villages, FL, a large retirement community which uses a lot of dual lane roundabouts. The pamphlets start by stating the rules have changed from whatever they were previously. Even then, the roundabouts will have varying lane designations, based on the flow of traffic.
Quote from: kj3400 on April 11, 2013, 07:07:24 PM
The Dutch got it right with their turboroundabouts:
indeed. generally speaking, a two-lane roundabout should be striped so that for every rotation (from one intersecting road to the next), the lanes "sweep right" one. so that the left lane is given the option to exit unimpeded, and the right lane is a forced exit. therefore, anyone rotating along in the right lane would have his conflict explicitly marked, and - as mentioned before - it would not be a "yield to traffic on left (very odd)" as much as a "change lanes as usual, or exit as usual".
my intuition is, for lane quantities greater than two, a sweep right of exactly one per rotation is sufficient. this as opposed to a "sweep two" for three lanes, a "sweep three" for four, etc.
but I am currently too lazy to draw this out.
again, I think any roundabout which is legally defined as a "turbine",
but is striped as concentric (i.e. Rhode Island), benefits only the ambulance chasers.
Quote from: DaBigE on April 11, 2013, 05:18:59 PM
This is a prime example of why you do not use concentric circles to mark the circulatory roadway or do not stripe the circulatory roadway whatsoever. So many design flaws...path overlap, long tangents connecting approaches and exits, no truck apron...must have been the first multilane roundabout of someone's design career.
Spoken like someone who has designed a few in his day? :spin:
Quote from: agentsteel53 on April 11, 2013, 05:33:04 PM
(I don't know why there are yield stripes on the exit splits... I think that may be a design error in the diagram.)
I'm guessing those aren't yielding indications, they're puppy tracks (guiding drivers around). That isn't how the US typically stripes exits, as far as I know.
A bunch of examples can be found here (my computer is going really slow but if I remember right there are many lane variations in the back):
http://onlinepubs.trb.org/onlinepubs/nchrp/nchrp_rpt_672.pdf
P.S. Where is this (originally posted) roundabout?
Quote from: jeffandnicole on April 11, 2013, 07:13:37 PM
Using the original example, both are incorrect. If everyone followed the red line, then what use is the outer lane?
Going straight... (which can also be done from the left lane if the entrance and exit are both two lanes)
Quote from: johndoe on April 11, 2013, 07:32:17 PM
P.S. Where is this (originally posted) roundabout?
West of Orlando in a new development called Horizon West. The red path will soon become the main route for Disney workers to reach the area north of the Magic Kingdom from the southeast.
http://maps.google.com/maps?hl=en&ll=28.444129,-81.55956&spn=0.006084,0.008256&gl=us&t=k&z=18
When I navigate the Bear Mountain Bridge roundabout (2 lanes), I take whichever approach lane has a shorter queue, enter the roundabout, and then figure out where I fit between vehicles in the right lane if I happen to have ended up on the left.
Quote from: NE2 on April 11, 2013, 06:51:22 PM
Quote from: theline on April 11, 2013, 05:14:44 PM
I don't see the problem. In the absence of striping or signage to clarify, the rules of the road apply.
The rotary part must be treated as a two-lane, one-way road. Each driver is entitled to his lane. When a driver wants to turn off, which is of course always a right turn, he should do so from the right lane. If he's in the left lane, he needs to yield to right-lane traffic when leaving his lane.
http://www.wsdot.wa.gov/safety/roundabouts/#multi
And that page gives the answer, at least here in Washington. The answer isn't red or blue, it's whoever arrived at the roundabout first.
Quote from: Kacie Jane on April 11, 2013, 10:54:45 PM
Quote from: NE2 on April 11, 2013, 06:51:22 PM
http://www.wsdot.wa.gov/safety/roundabouts/#multi
And that page gives the answer, at least here in Washington. The answer isn't red or blue, it's whoever arrived at the roundabout first.
Huh? So when you enter a roundabout, you need to keep track of all the vehicles already in it, in case one of them decides to cut you off? Where is this written on the WSDOT page (which says blue is not the correct way to turn left)?
This is a very bad roundabout to use as an example for those familiarizing themselves with roundabout rules :sombrero: Check out the previous link I posted for many logical lane configurations. Remember...no lane changes within circulating roadway should occur!
I think another funny situation in the original roundabout is if you wanted to make a left from the main road...
(https://www.aaroads.com/forum/proxy.php?request=http%3A%2F%2Fi48.tinypic.com%2F2vjskuo.jpg&hash=f923b86342d34a213a577cf9554024b7e4229dc3)
You're "better off" doing so from the right lane (assuming no one is going to proceed through in the left lane)! :-D
Quote from: johndoe on April 11, 2013, 07:32:17 PM
Quote from: DaBigE on April 11, 2013, 05:18:59 PM
This is a prime example of why you do not use concentric circles to mark the circulatory roadway or do not stripe the circulatory roadway whatsoever. So many design flaws...path overlap, long tangents connecting approaches and exits, no truck apron...must have been the first multilane roundabout of someone's design career.
Spoken like someone who has designed a few in his day? :spin:
I've had my hands in a couple dozen now...basic 1x1 single-laners to 2x3 multilaners, some with spirals and partial &/or full right turn bypass lanes.
Quote from: johndoe on April 12, 2013, 12:22:14 AM
(https://www.aaroads.com/forum/proxy.php?request=http%3A%2F%2Fi48.tinypic.com%2F2vjskuo.jpg&hash=f923b86342d34a213a577cf9554024b7e4229dc3)
Base on this image alone, it should have been designed as a 1x2 (one lane circulating in front of the NW/SE approaches; two lanes circulating in front of the SW approach and empty NE side) + truck apron. Something very similar to this one: http://goo.gl/maps/23VcB (http://goo.gl/maps/23VcB)
Vancouver, WA, has a really well marked roundabout.
http://goo.gl/maps/sbq9v
Quote from: DaBigE on April 12, 2013, 02:13:15 AM
Base on this image alone, it should have been designed as a 1x2 (one lane circulating in front of the NW/SE approaches; two lanes circulating in front of the SW approach and empty NE side) + truck apron. Something very similar to this one: http://goo.gl/maps/23VcB (http://goo.gl/maps/23VcB)
The northeast approach, which will open in a few weeks, will be four lanes.
Quote from: NE2 on April 11, 2013, 03:56:21 PMThe blue guy is not using the roundabout correctly, but there are no signs at this one telling you which lane to use.
Except the blue guy doesn't have right-of-way. It is clear (at least to British eyes) that the red guy won't keep driving around and around and thus the blue guy's way isn't clear (as the red guy would either leave the roundabout before, or at the same time as him) and he must yield.
If the blue car is on the roundabout without seeing the red car, then the red car yields to it before leaving, but also honks his horn and has a legit gripe about being cut up!
However some roadside indication that to turn left you need to be in the left lane wouldn't go amiss, especially as you Americans need to be told explicitly what to do, even when like that it's common sense! (us Brits have to be explicitly told otherwise when we can turn right from the left lane as well as the right)
What Hennepin County did (https://maps.google.com/?ll=44.883512,-93.267521&spn=0.001085,0.00284&t=k&z=19) in Richfield, MN. In short, if you want to "turn left", you use the left lane.
Quote from: agentsteel53 on April 11, 2013, 05:58:35 PM
Quote from: 1995hoo on April 11, 2013, 05:55:35 PM
In some jurisdictions neither driver "has" the right of way and instead it's a question of who is required to yield the right of way.
Hypertechnical distinction, I know.
and essentially meaningless, no? one driver "has", the other is "required to yield".
I don't think there is any legitimate situation where both drivers are "required to yield" (deadlock), or when both drivers "have" (disaster).
I think–though I don't know for sure–that part of the rationale for the law not considering the one driver to "have" the right-of-way is that it allows for them to ticket both drivers, the one for failing to yield and the other for something along the lines of failure to pay full time and attention (because the attentive driver would presumably go around the roundabout again instead of turning into another vehicle).
I don't know how often that actually happens, mind you.
Quote from: KEK Inc. on April 12, 2013, 02:21:49 AM
Vancouver, WA, has a really well marked roundabout.
http://goo.gl/maps/sbq9v
indeed - looks like a textbook turbine layout.
Quote from: english si on April 12, 2013, 06:11:03 AM
Except the blue guy doesn't have right-of-way.
the problem is - the way that roundabout is striped, the blue guy
does have right of way. I am pretty sure that a dashed lane stripe is defined the same in all US jurisdictions:
a boundary between lanes - to cross it, you must give right of way to vehicles already within the target lane.
QuoteIt is clear (at least to British eyes) that the red guy won't keep driving around and around
he might. the striping has forced him to.
to escape the left lane here seems to be the equivalent of running a red light because you're figuring that, after 5-10 minutes, it just won't turn green for you, and it is safe to proceed.
QuoteIf the blue car is on the roundabout without seeing the red car, then the red car yields to it before leaving, but also honks his horn and has a legit gripe about being cut up!
again, not the way it is striped. the red car is being inconsiderate here: it's the equivalent of someone to your left wanting to exit the freeway and you remain exactly paralleling him, denying the lane change. but in heavier traffic patterns (more than just blue car, red car) it sometimes happens that way, and one must be occasionally inconsiderate to a particular driver, in order to proceed smoothly on the whole.
effective driving unfortunately resolves to "never enter the left lane" for this roundabout, meaning that its capacity is dropped in half - all by idiotic striping.
QuoteHowever some roadside indication that to turn left you need to be in the left lane wouldn't go amiss, especially as you Americans need to be told explicitly what to do, even when like that it's common sense!
depends on which part of the US. in the northeast, home to all kinds of bizarre and poorly signed roundabouts/traffic signals/rotaries/who gives a shit, we generally figure it out by honking and swearing. some people follow the stripes; some people follow the rules of an implied turbine... and when they come into conflict, it is "priority goes to the most determined and/or maniacal"... which seems to be how Paris operates too.
in other parts of the US, drivers are morons. if there were a concentric-circle roundabout placed in Miami, we'd have, in the first hour, a fatal head-on collision, two drive-by shootings, and a guy eating someone's face.
Quote(us Brits have to be explicitly told otherwise when we can turn right from the left lane as well as the right)
aren't most of your roundabouts striped that way? (well, flipped 180 degrees due to drive-on-left instead of drive-on-right)
The one in Monmouth IL is unmarked ex for Yield signs at entrance . Galesburg has a preferred direction with yield signs on the minor road.
In the 60s Monmouth was unsigned and unmarked and had more traffic with semis before its bypass was built
Quote from: 3467 on April 12, 2013, 10:07:48 AM
The one in Monmouth IL is unmarked ex for Yield signs at entrance . Galesburg has a preferred direction with yield signs on the minor road.
In the 60s Monmouth was unsigned and unmarked and had more traffic with semis before its bypass was built
Monmouth:
http://goo.gl/maps/IUvEF
Galesburg:
http://goo.gl/maps/ci4pb
the Monmouth one looks to be the town square. there are entrances and exits for quadrantal parking bays. I'll bet the speed limit is no more than 20, and a lot of traffic is traveling at 5-10. there, you can probably resolve all conflicts via eye contact.
Galesburg's is not only striped concentric, but the supplemental arrows seem to make it appear that, in order to exit the innermost of three lanes, one must explicitly perform a lane-change and yield to traffic in the middle lane. it seems like the only reason you would ever need to use the innermost lane is to make a left from the major onto the minor, or to go straight on the minor.
in that case, you need to merge over two lanes within one quadrant (twice, if going straight)... this seems less tricky than crossing four lanes of the major if it were just a simple intersection, but - in contraindication to how a turbine works - I would have absolutely no expectation of the two outer lanes (which can be viewed as the through lanes of the east-west road, just winding around a bit) yielding to me when I wanted to exit.
the inner lane, therefore, seems to function most analogously to a left entrance to a controlled expressway: I slow or stop, wait for traffic to my right to subside, then merge two lanes right, and exit: the "entrance" (if going straight on the minor), and "exit" maneuvers both fully require yielding. this is reinforced by the fact that only the side street gets yield signs.
I cannot tell how high speed the main road is... but it seems like a decent solution to avoid a traffic light, while giving north-south traffic an opportunity to not have to cross four lanes of major road in one burst.
This is why New Jersey's method is best: Shut your eyes, enter circle, and do whatever is necessary to come out alive.
Sure, the Jersey Circle tends to (not always) have people yield after they are in the circle, not entering the circle. And Jersey Circles tend to be on roads that are high volume, leading to congestion. But throughout the years, the Jersey Circles rarely had pavement lines within the circle and rarely had signage detailing who should yield. They worked...and worked well (as long as the volume of traffic didn't exceed capacity).
Sure, they *seem* unsafe, but accidents are low in a Jersey Circle, and most of them are of the typical side-swipe variety which still occur in a roundabout. Stand around one and you'll hear some horn-honking, but people generally are looking out for themselves, just like on any other stretch of roadway.
There was never debate about which lane one should be in when entering/leaving the circle. There was never debate about how long you should remain left, then get right.
Since there are so many configurations and ideas of how a roundabout should be stripped, a driver can encounter many varying options at consecutive roundabouts, which in itself leads to confusion because there's no consistancy. At the very most, post the Yield signs for motorists entering the roundabout, and paint some short skip lines through the middle of the travel portion of the roundabout to split the lanes. Motorists will figure out the rest.
Quote from: jeffandnicole on April 12, 2013, 11:20:48 AM
Sure, the Jersey Circle tends to (not always) have people yield after they are in the circle,
can you elaborate on this? who is yielding to whom? (and why not always?) are there any Jersey circles which have customs which are completely contradictory to how they are striped?
The roundabout at the east end of the recently rebuilt College Ave bridge over the Fox River here in Appleton is a hybrid multi-lane design (two lane major street with two two-lane streets branching off with unbalanced turn volumes).
http://goo.gl/maps/Wzm5l
The decision to go with it was after traffic studies as well as an engineer's report that stated that to go with a conventional signalized intersection would have required taking six additional houses and cost about a half-million dollars more than the roundabout.
It works very, very well - about four out of every five times that I drive through it, I get through with no delays, even at the peak afternoon commuter drive times.
BTW, this was the roundabout that was described in WisDOT public brochures on the matter over the past several years.
Mike
Quote from: agentsteel53 on April 12, 2013, 11:28:34 AM
Quote from: jeffandnicole on April 12, 2013, 11:20:48 AM
Sure, the Jersey Circle tends to (not always) have people yield after they are in the circle,
can you elaborate on this? who is yielding to whom? (and why not always?) are there any Jersey circles which have customs which are completely contradictory to how they are striped?
Jersey circles tend to favor the major road instead of who's already in the circle. They didn't use to be signed so that traffic pattern was because the major road had more traffic entering the circle. Now they seem to be signed, well only signed to show when you need to yield. And there are times when traffic in the circle yields to traffic entering the circle. I think the signage just clarified how the circle was typically functioning on its own.
Of the ones that are left I'm most familiar with are the Brooklawn circles. You can see that the one on the right has two examples of traffic in the circle yielding to traffic entering the circle.
http://goo.gl/maps/U5GCc
The circle on the left should have two instances of traffic in the circle yielding to traffic entering the circle since US 130 is the route that typically doesn't yield. But for some reason they haven't fully signed that circle.
Quote from: mgk920 on April 12, 2013, 01:26:00 PM
http://goo.gl/maps/Wzm5l
with regard to the road coming from the west: the overhead view shows it two-lane; the street view three-lane. which is it?
the overhead view shows some perfect turbine striping, with auxiliary arrows. I wanted to check the street view for approach signage, and that paints a different picture... probably excellent as well; I was just too lazy to surf back and forth on the street view to see anything more than a sign-per-lane gantry setup: left lane left turn only, center lane straight only, right lane right turn only. very logical.
Quote from: agentsteel53 on April 12, 2013, 01:42:25 PM
Quote from: mgk920 on April 12, 2013, 01:26:00 PM
http://goo.gl/maps/Wzm5l
with regard to the road coming from the west: the overhead view shows it two-lane; the street view three-lane. which is it?
the overhead view shows some perfect turbine striping, with auxiliary arrows. I wanted to check the street view for approach signage, and that paints a different picture... probably excellent as well; I was just too lazy to surf back and forth on the street view to see anything more than a sign-per-lane gantry setup: left lane left turn only, center lane straight only, right lane right turn only. very logical.
The Streetview imagery from Appleton is still the stuff that was shot in October of 2007, before the former two-lane bridge was replaced. The Streetview shows the old intersection configuration.
The new bridge opened in late October of 2009.
Their camera car was out and about here last summer, so new imagery should be uploaded at any time.
Mike
Quote from: BrianP on April 12, 2013, 01:35:35 PM
Quote from: agentsteel53 on April 12, 2013, 11:28:34 AM
Quote from: jeffandnicole on April 12, 2013, 11:20:48 AM
Sure, the Jersey Circle tends to (not always) have people yield after they are in the circle,
can you elaborate on this? who is yielding to whom? (and why not always?) are there any Jersey circles which have customs which are completely contradictory to how they are striped?
Jersey circles tend to favor the major road instead of who's already in the circle. They didn't use to be signed so that traffic pattern was because the major road had more traffic entering the circle. Now they seem to be signed, well only signed to show when you need to yield. And there are times when traffic in the circle yields to traffic entering the circle. I think the signage just clarified how the circle was typically functioning on its own.
Of the ones that are left I'm most familiar with are the Brooklawn circles. You can see that the one on the right has two examples of traffic in the circle yielding to traffic entering the circle.
http://goo.gl/maps/U5GCc
The circle on the left should have two instances of traffic in the circle yielding to traffic entering the circle since US 130 is the route that typically doesn't yield. But for some reason they haven't fully signed that circle.
Exactly. The Brooklawn Circles are perfect examples of almost everything one can find at a Jersey Circle. And down forget the curb cuts for the businesses that also enter and exit the circle. At the main Brooklawn Circle, there are a total of about 12 or 13 ways to enter that circle, and that doesn't include the curb cuts and driveways along the roads within 100' or so of the circle.
Quote from: NE2 on April 12, 2013, 12:14:24 AM
Quote from: Kacie Jane on April 11, 2013, 10:54:45 PM
Quote from: NE2 on April 11, 2013, 06:51:22 PM
http://www.wsdot.wa.gov/safety/roundabouts/#multi
And that page gives the answer, at least here in Washington. The answer isn't red or blue, it's whoever arrived at the roundabout first.
Huh? So when you enter a roundabout, you need to keep track of all the vehicles already in it, in case one of them decides to cut you off? Where is this written on the WSDOT page (which says blue is not the correct way to turn left)?
My argument would be that if people are entering the roundabout correctly, then there should be enough space between vehicles that conflicting movements -- even movements that conflict only because someone is using the roundabout improperly -- don't actually conflict.
In other words, if blue insists on turning left from the right lane, as long as he yields to all traffic in the roundabout (and not just the right lane), then they shouldn't have a problem because they've already let red go in front of them (or red is far enough behind them that blue isn't cutting red off).
Quote from: Kacie Jane on April 12, 2013, 03:26:23 PM
My argument would be that if people are entering the roundabout correctly, then there should be enough space between vehicles that conflicting movements -- even movements that conflict only because someone is using the roundabout improperly -- don't actually conflict.
this does not appear to be true. I have seen roundabouts which are plenty full, where a conflicting movement could very well lead to trouble.
I think that in practice, you're right. But if the roundabout is plenty full, and a car entering the roundabout squeezes in and causes a conflicting movement, then they're not properly obeying the sign (which at least in WA is always posted) that says yield to all traffic in roundabout.
But if the roundabout is so full that even the most patient drivers are forced to squeeze in without properly yielding, then it was probably a location that called for something more than a roundabout in the first place.
agentsteel53 , You are right exactly right about Monmouth. Its problems are in the past except.....when people used to Galesburg use it and treat it like that one. A real risk of rear end collision form stopping in the roundabout.
Galesburgs is just strange . It was once a square. A real joke. The current speeds are low It turns to 20 going into downtown and goes back to 30 heading out. The north south road is a major minor road in traffic terms. Monmouth roundabout users don't seem to have the same navigation problem.
The Indianapolis suburb of Avon has been putting up roundabouts over the past few years, three of them alone along Dan Jones Road, a north-south road that lies in between SR 267 and Ronald Reagan Parkway. The three roundabouts are all two lanes, but neither Dan Jones Roads or the roads it intersects are four lanes. The roadway on all sides of the roundabouts are four lanes but quickly go back to two lanes, making the second lane kind of pointless. Now I understand there's probably an intent to widen Dan Jones to four-lanes which would make the roundabouts more useful at two-lanes, but they can't even get the RR Pkwy finished, or widened, so that seems unlikely. So the question I always have when I pass thorugh one of these roundabouts is what the point of being in the right lane is since I just have to move back over. At least the Carmel roundabouts make more sense for the most part.
Here's an example at Dan Jones and 100 North (10th Street:)
https://maps.google.com/maps?q=Avon,+IN&hl=en&ll=39.777796,-86.379071&spn=0.004634,0.010568&sll=39.766555,-86.441277&sspn=4.74553,10.821533&t=k&hnear=Avon,+Hendricks,+Indiana&z=17
On the bright side, at least there are signs and road markers, Indiana's pretty good about that.
Quote from: Kacie Jane on April 12, 2013, 03:26:23 PM
Quote from: NE2 on April 12, 2013, 12:14:24 AM
Quote from: Kacie Jane on April 11, 2013, 10:54:45 PM
Quote from: NE2 on April 11, 2013, 06:51:22 PM
http://www.wsdot.wa.gov/safety/roundabouts/#multi
And that page gives the answer, at least here in Washington. The answer isn't red or blue, it's whoever arrived at the roundabout first.
Huh? So when you enter a roundabout, you need to keep track of all the vehicles already in it, in case one of them decides to cut you off? Where is this written on the WSDOT page (which says blue is not the correct way to turn left)?
My argument would be that if people are entering the roundabout correctly, then there should be enough space between vehicles that conflicting movements -- even movements that conflict only because someone is using the roundabout improperly -- don't actually conflict.
In other words, if blue insists on turning left from the right lane, as long as he yields to all traffic in the roundabout (and not just the right lane), then they shouldn't have a problem because they've already let red go in front of them (or red is far enough behind them that blue isn't cutting red off).
So what you actually mean is who arrives at the northwest corner first. I understand what you mean, but there's still potential for problems based on different speeds (what if red is a bike, already at the southwest corner when blue enters?).
Also, your argument falls apart completely if blue and red both enter from the northeast and blue makes a U-turn in the right lane of the roundabout. Then they can both enter the roundabout at the same time without any issues, and if their angular speed is identical they crash.
Well, I think the issue is that you're trying to determine who has the right of way when one of the maneuvers is illegal. To quote Donald Rumsfeld, The answer is that there is no answer.
Quote from: Kacie Jane on April 12, 2013, 10:10:52 PM
Well, I think the issue is that you're trying to determine who has the right of way when one of the maneuvers is illegal.
[disputed - see talk]
1. Kacie Jane is correct; you can't represent potential traffic conflicts accurately with a still image and lines; you're not thinking fourth dimensionally -- it doesn't matter that their paths cross because one of them is supposed to yield to the other (depending on the configuration) when they enter the circle. Even if they're both retarded and change lanes 2 or 3 times in the circle, they should have entered in such a way that they're no longer parallel.
2. I also agree with jeffandnicole regarding the Jersey circles. There are certain places in NJ in which things kept relatively ambiguous tend to work the best, for example the huge un-striped conglomerations on the turnpike after the toll plazas and right before the ramp split. The circles work because people's movements within a circle are caused by human reaction, and not by a function of math or due to common sense. What the red and blue lines do are not only dependent on each other, but also on all of the other cars (or lack or cars) that may or may not be in the circle at that time. Think of it like particle-wave duality -- these are not single cars going through a circle, it's a wave that is subject to interference from --and causes interference to-- itself in such a way that it's inefficient to tell drivers where to go using a static policy (striping, laws, etc). The shortest distance is always a straight line -- unless there's a car in the way. Since the "lanes" can't react to the cars in the circle, it's inefficient to statically stripe a circle, just as it would be inefficient to stripe the area immediately after a toll plaza -- the distribution of car flow is completely depending on what booths are open at that moment in time.
3. I don't care what anyone says the NJ traffic circle sign is AWESOME.
I should probably stop talking, as I feel like I'm digging myself a hole I can't get out of. But I come from a magical land where we seem to have developped this fascination with the roundabout and think it's a cure for all that ails us, but that's okay because at least when we overuse it, it's properly signed with the lane assignments clearly marked. Because I find the signage so clear, I've never paid too much attention to the pavement markings, but this one (http://goo.gl/maps/l0U3W) (the first one I thought of that's two lanes all the way around) seems to be well-striped according to the diagram Jake posted.
I do agree that poor striping may be an issue elsewhere. And poor signing as well, since NE2 mentioned in the original post that there's no sign specifically prohibiting blue's movement. And I don't know what laws elsewhere are regarding turning left from the right lane of a multi-lane roundabout.
But from a jaded NW Washingtonian's perspective, the answer to the original question is clear. Blue shouldn't be making that movement, in part because it conflicts with red's movement. But if he properly yields upon entering the roundabout, he shouldn't have a problem making his movement anyway.
Quote from: agentsteel53 on April 12, 2013, 09:40:11 AM
aren't most of your roundabouts striped that way? (well, flipped 180 degrees due to drive-on-left instead of drive-on-right)
In my experience, most of the roundabouts in the UK are unstriped.
Quote from: realjd on April 13, 2013, 06:51:06 AM
Quote from: agentsteel53 on April 12, 2013, 09:40:11 AM
aren't most of your roundabouts striped that way? (well, flipped 180 degrees due to drive-on-left instead of drive-on-right)
In my experience, most of the roundabouts in the UK are unstriped.
Though we typically work on a principle of implied common sense, so we don't need to be so prescriptive in our descriptive road markings... Also there's typically little room to mark lanes for the short distances involved!
Here's two lanes without marking it (http://goo.gl/maps/qsKZo). Also note that right-hand lane on the joining road has yielded to Mr Streetview, but the left-hand lane hasn't. This is because it's quite clear we aren't going off to where the old wall is - road position (and you'd be indicating left to turn off) says Mr Streetview is going to continue around the roundabout to at least the next exit. Also note that no one is stupid enough to turn right from the left lane, even though there's no markings saying they shouldn't - and it's not just because it is busy!
Whether there are signs saying so or not, this only shows why it is
not a good idea to use the
right lane when you intend to turn
left. Properly striped roundabouts can eliminate this issue. To use agentsteel53's illustration more clearly, I've redrawn the red and blue lines to match the OP.
Quote from: agentsteel53 on April 11, 2013, 05:47:30 PM
(https://www.aaroads.com/forum/proxy.php?request=http%3A%2F%2Fi1092.photobucket.com%2Falbums%2Fi410%2Fkphoger%2Frbouts_zps94b0e1b1.png&hash=31753a8767eb2718d91e0bef99ab3cc41ca93789)
Quote from: realjd on April 13, 2013, 06:51:06 AM
Quote from: agentsteel53 on April 12, 2013, 09:40:11 AM
aren't most of your roundabouts striped that way? (well, flipped 180 degrees due to drive-on-left instead of drive-on-right)
In my experience, most of the roundabouts in the UK are unstriped.
MUTCD presents multi-lane roundabout markings as an
option, not Guidance (recommended) or Standard.
The 2009 MUTCD has an entire chapter (Chapter 3C (http://mutcd.fhwa.dot.gov/htm/2009/part3/part3c.htm)) on roundabout markings, with 14 examples of possible lane marking treatments. Several are of the "turbine" type that gradually direct a driver from the inner to the outer lane.
Taking a look at some of those examples might be instructive in answering some of the questions brought up in this thread. The important takeaway is that the markings (and signs) should clearly indicate what lanes are appropriate for each possible turning movement, such that issues of a left turning vehicle in an outer lane should not cause conflicts if the roundabout is adequately marked. The image in the OP and some others aren't adequately marked, thus causing the ambiguity.
Quote from: Steve on April 13, 2013, 03:00:35 PM
MUTCD presents multi-lane roundabout markings as an option, not Guidance (recommended) or Standard.
Actually, the current MUTCD has a guidance statement (3C.02, p3) that says multi-lane roundabouts should have lane markings in the circulating roadway to guide drivers to the appropriate exit lane.
Quote from: roadfro on April 13, 2013, 05:56:29 PM
Quote from: Steve on April 13, 2013, 03:00:35 PM
MUTCD presents multi-lane roundabout markings as an option, not Guidance (recommended) or Standard.
Actually, the current MUTCD has a guidance statement (3C.02, p3) that says multi-lane roundabouts should have lane markings in the circulating roadway to guide drivers to the appropriate exit lane.
*hasn't worked on roundabout striping since pre-2009, sorry*