Crash prone 'modern roundabouts'

[kphoger]

I've never seen the problem at roundabouts to be a failure to yield. No, I've seen much more confusion arise when a driver can't STOP yielding. At some point, you have to grow some balls and GO already.

[Sykotyk]

I've never seen the problem at roundabouts to be a failure to yield. No, I've seen much more confusion arise when a driver can't STOP yielding. At some point, you have to grow some balls and GO already.

But that has nothing to do with an accident. A car doesn't get hit in the roundabout because a driver is timid to enter.

An accident occurs because a car enters when they're not supposed to.

The problem is, a roundabout should be treated in the same manner as a four-way stop. If it's just one car from one approach, you get to go unimpeded. If it's two cars, then the same process as a stop sign (vehicle to the right goes, if it's on-coming traffic, they can both go). if it's W and S that arrive, S gets to go first because they're on the right.

That's generally understood by the populus (though, there are many I've seen that don't understand when you get to go at a jammed four-way stop sign). The issue is when a roundabout is jammed with traffic stalled at 2, 3, or 4 approaches. The first car into the roundabout gives the impression to those behind them that they can 'tag along' and suddenly that entire approach clears the roundabout while the other approaches all have to wait. And that's when you get cars slightly behind the line racing to get up into the roundabout before another approach can start. And then the next approach begins to clear out in the same manner.

It should be one-at-a-time in a counter-clockwise fashion, just as a stop sign. This isn't the big traffic circles found in New England. These are much smaller and REPLACE stop-signed or signalized intersections. The circle is not a road in the manner of how a large traffic circle, generally found in the New England states, is basically entering an entirely new road, one that is one-way and forms a loop.

That's the problem I've come across. And it's especially true during rush hour when a roundabout is placed on a major thoroughfare at an intersection with a less used crossroad. The thoroughfare treats it like they get constant stream of traffic and the side roads have to wait. Rather than the car behind the car at a yield sign realizing they must wait until the first car at each other approach also clears the roundabout. And THEN they get to go. Same as a stop sign.

Instead, it's treated as "since the car in front of me is the only one in the roundabout, I can enter because I don't have to yield to anyone on my left". Which is true, but it makes entering the roundabout an aggressive act, rather than a defensive/regulated act.

[english si]

That doesn't even make sense to be signed at 55 mph.  Looks like 45 might be more appropriate.

Surely US drivers are capable of not driving at the speed limit if it is unsafe to do so there. Oh wait...

These are on a 70mph Dual Carriageway trunk road. (BTW, the UK doesn't allow reduced limit for one thing like a junction, preferring ample warning signs, rumble strips, and drivers to not be slaves to driving to the posted limit. Nor does it allow traffic signals on 70mph roads). AADT on the A43 is around 37000 in this area (between 36200 north of Brackley and 37800 south of the A421). Looking, it seems that each roundabout on the A43 (with the exception of the ones at the M40, where there was a terrible 'improvement' scheme that has now been reversed) seems to get about 8 collisions every 5 years, with perhaps 1 of them fatal. There's room for improvement, but the only way to do it is grade-separation (which, as well as expensive and gaining little in journey time savings, will increase the number of idiots driving 100mph along the road, undermining all the safety benefits as more people crash off, killing themselves).

[english si]

But that has nothing to do with an accident. A car doesn't get hit in the roundabout because a driver is timid to enter.

Do accident stats only include those on the circulatory carriageway, or also at approaches? A timid driver is likely to get driven into the back of. And they also create accidents around them - you even give an example of how: a not very assertive driver creates a queue, and when they go, the queue thinks its clear for them.

Better driver education would go a long way to improving US roundabout safety.

[kphoger]

But that has nothing to do with an accident. A car doesn't get hit in the roundabout because a driver is timid to enter.

Do accident stats only include those on the circulatory carriageway, or also at approaches? A timid driver is likely to get driven into the back of. And they also create accidents around them - you even give an example of how: a not very assertive driver creates a queue, and when they go, the queue thinks its clear for them.

Better driver education would go a long way to improving US roundabout safety.

Also...  A driver too timid to go from the entering left lane makes for an obstruction the right-lane driver might not be able to see around; said right-lane driver might take an unwarranted chance at entering the roundabout out of impatience.

Also...  What I've seen more often is drivers who become timid within the circulating roadway, sometimes coming to a full stop inside the roundabout.  This most certainly does increase the risk of accident.

[kalvado]

Also...  What I've seen more often is drivers who become timid within the circulating roadway, sometimes coming to a full stop inside the roundabout.  This most certainly does increase the risk of accident.

We have a roundabout with a crosswalk 10' from the outer circle. I've been there in both capacities - and as pedestrian, I am really scared since you are not seen until last second. You better wait until traffic gap.. and then someone hits their brakes and stops in the middle of the circle...  Hopefully they will not hit me when rear-ended...
As a driver, I am really scared of pedestrians in that crosswalk - whatever I do would be wrong, both stopping in the circle and  not yielding to crosswalker..

[english si]

We have a roundabout with a crosswalk 10' from the outer circle.

That's too close. Needs to be more like 30' - especially on the exit side of the roundabout.

When we have crossings next to roundabouts (normally one, maybe two, car lengths from it) in the UK, they aren't ones that give priority to pedestrians (though obviously road vehicles don't have the right to hit them), but we will have signalised crossings or zebras (where cars are meant to yield to pedestrians waiting to cross) if they are a bit further down the road and the visibility and stacking issues are sorted.

[jeffandnicole]

Also...  What I've seen more often is drivers who become timid within the circulating roadway, sometimes coming to a full stop inside the roundabout.  This most certainly does increase the risk of accident.

We have a roundabout with a crosswalk 10' from the outer circle. I've been there in both capacities - and as pedestrian, I am really scared since you are not seen until last second. You better wait until traffic gap.. and then someone hits their brakes and stops in the middle of the circle...  Hopefully they will not hit me when rear-ended...
As a driver, I am really scared of pedestrians in that crosswalk - whatever I do would be wrong, both stopping in the circle and  not yielding to crosswalker..

Have a link for that roundabout?

[kalvado]

We have a roundabout with a crosswalk 10' from the outer circle. I've been there in both capacities - and as pedestrian, I am really scared since you are not seen until last second. You better wait until traffic gap.. and then someone hits their brakes and stops in the middle of the circle...  Hopefully they will not hit me when rear-ended...
As a driver, I am really scared of pedestrians in that crosswalk - whatever I do would be wrong, both stopping in the circle and  not yielding to crosswalker..

Have a link for that roundabout?

https://www.google.com/maps/@42.689025,-73.8315784,71m/data=!3m1!1e3
southwestern leg crossing mostly - it is used by students walking between dorms and campus.

[jeffandnicole]

That's a standard design but it's way too close. College near me has one like that as well.  Moving it about 100 feet from the roundabout allows for a little storage room.

[kalvado]

That's a standard design but it's way too close. College near me has one like that as well.  Moving it about 100 feet from the roundabout allows for a little storage room.

If you look carefully, there is a foot path which cut across roundabout approach curve, saving maybe 10 feet. You really think that same people would walk 100 feet just because that is where crosswalk is marked?  Then you may be interested in buying that bridge on the interstate!
It is just the case when roundabout was built  for the sake of building a roundabout.  There were a lot of other improvements within that project, but they could be implemented without a circle - and probably at a lower cost.

[jeffandnicole]

What's preventing less from just crossing into the center right now?

There are methods to keep people using the crosswalks. Decorative fencing, for example.

(ugh...less should have been "peds"!!!

[Sykotyk]

What's preventing less from just crossing into the center right now?

There are methods to keep people using the crosswalks. Decorative fencing, for example.

Considering people have to extol energy to walk, making them walk further just makes the find a shortcut. Have you ever seen a grassy area near a building with a well worn foot path because people were too lazy to walk the extra 10-15-20 feet to stay on pavement? Same issue. Only way to stop them would be to line the entire thing with fencing, and that would last as long as the first tractor trailer that goes up and over the curb or drunk at night sideswipes it. And since it's decorative only, it won't stand up to the abuse. And unless its repaired/replaced quickly, it will look like a guady eyesore.

[johndoe]

The problem is, a roundabout should be treated in the same manner as a four-way stop.

if it's W and S that arrive, S gets to go first because they're on the right.

It should be one-at-a-time in a counter-clockwise fashion, just as a stop sign.

The thoroughfare treats it like they get constant stream of traffic and the side roads have to wait.

they must wait until the first car at each other approach also clears the roundabout. And THEN they get to go. Same as a stop sign.

"I can enter because I don't have to yield to anyone on my left". Which is true

Forgive me if this is harsh, but I don't think you understand roundabouts.  Everything I've quoted is wrong.  A roundabout is not a four-way stop.  Entering drivers yield to conflicting vehicles in the circulating roadway; it has nothing to do with the other approaches. 

[jeffandnicole]

The problem is, a roundabout should be treated in the same manner as a four-way stop.

if it's W and S that arrive, S gets to go first because they're on the right.

It should be one-at-a-time in a counter-clockwise fashion, just as a stop sign.

The thoroughfare treats it like they get constant stream of traffic and the side roads have to wait.

they must wait until the first car at each other approach also clears the roundabout. And THEN they get to go. Same as a stop sign.

"I can enter because I don't have to yield to anyone on my left". Which is true

Forgive me if this is harsh, but I don't think you understand roundabouts.  Everything I've quoted is wrong.  A roundabout is not a four-way stop.  Entering drivers yield to conflicting vehicles in the circulating roadway; it has nothing to do with the other approaches. 

His one-car-at-a-time idea would hopelessly jam up the roundabout approaches. It take a car a second or two to go thru an intersection. It would take a car several seconds to go thru a roundabout, especially if making a left or u-turn.

[Sykotyk]

The problem is, a roundabout should be treated in the same manner as a four-way stop.

if it's W and S that arrive, S gets to go first because they're on the right.

It should be one-at-a-time in a counter-clockwise fashion, just as a stop sign.

The thoroughfare treats it like they get constant stream of traffic and the side roads have to wait.

they must wait until the first car at each other approach also clears the roundabout. And THEN they get to go. Same as a stop sign.

"I can enter because I don't have to yield to anyone on my left". Which is true

Forgive me if this is harsh, but I don't think you understand roundabouts.  Everything I've quoted is wrong.  A roundabout is not a four-way stop.  Entering drivers yield to conflicting vehicles in the circulating roadway; it has nothing to do with the other approaches. 

How can anything you quoted be 'incorrect' when I specifically stated "should" in the very first line. It was my opinion.

The problem with roundabouts is people race to be the next one in, rather than following a set pattern on how to enter the roundabout. Wouldn't a four-way stop be just as dangerous if there were no set manner to enter other than 'whoever gets into the intersection first?'

[Sykotyk]

The problem is, a roundabout should be treated in the same manner as a four-way stop.

if it's W and S that arrive, S gets to go first because they're on the right.

It should be one-at-a-time in a counter-clockwise fashion, just as a stop sign.

The thoroughfare treats it like they get constant stream of traffic and the side roads have to wait.

they must wait until the first car at each other approach also clears the roundabout. And THEN they get to go. Same as a stop sign.

"I can enter because I don't have to yield to anyone on my left". Which is true

Forgive me if this is harsh, but I don't think you understand roundabouts.  Everything I've quoted is wrong.  A roundabout is not a four-way stop.  Entering drivers yield to conflicting vehicles in the circulating roadway; it has nothing to do with the other approaches. 

His one-car-at-a-time idea would hopelessly jam up the roundabout approaches. It take a car a second or two to go thru an intersection. It would take a car several seconds to go thru a roundabout, especially if making a left or u-turn.

How would it jam up the approaches anymore than they already are? More than one can be in a roundabout at the same time. But, only one approach at a time in rotation should get to go.

In a roundabout, there is no pattern. It's 'every man, woman, and child for themselves' and what I see at roundabouts is vehicles driving dangerously fast and cutting into the roundabout so they can get through it without waiting.  As for 'yielding' even that is onerous simply because how much space to yield is left up to the one at the yield sign. Yield to traffic in the roundabout would mean the entire roundabout. Or, 10 feet. Whichever doesn't damage their bumper.

And that's not even getting into two-lane or more roundabouts, where now you have merging traffic and lane-changing traffic to deal with, where the worst of it is on your right, the blindside of your vehicle.

Then we're not even discussing the elephant in the room, and that's just inattentive and ignorant drivers who don't know or are unable to handle a particular situation. A stop sign or traffic light has order and structure. A roundabout doesn't. Primarily because they weren't really taught to those who started driving 10-15 or more years ago. Where a yield sign generated delineated financial responsibility for an accident, rather than a steadfast traffic rule. Highway onramps a testament to that.

[jeffandnicole]

How would it jam up the approaches anymore than they already are? More than one can be in a roundabout at the same time. But, only one approach at a time in rotation should get to go.

they must wait until the first car at each other approach also clears the roundabout. And THEN they get to go. Same as a stop sign.

[kphoger]

Wouldn't a four-way stop be just as dangerous if there were no set manner to enter other than 'whoever gets into the intersection first?'

But that IS the only set manner to enter a four-way-stop. The only time yielding to the right comes in to play at all is when two cars get there at exactly the same time, which is NOT most of the time. And there are some jurisdictions where yielding to the right isn't even codified, but rather a common courtesy.

In other words, there is a set pattern on how to enter a four-way stop intersection, and that pattern is this: Whoever gets there first goes first; if you and the car to your right get there at the same time, then yield to the other driver (that last part may or may not be codified). Similarly, there is a set pattern on how to enter a roundabout: if nobody is imminently approaching on your left, then go on through; if someone is imminently approaching on your left, then yield.

If all four vehicles approach a roundabout at exactly the same time, then nobody has to wait at all: each can safely enter the roundabout because no other car is yet imminently approaching on the left. If all four vehicles approach a four-way stop at exactly the same time, then nobody quite knows who should go first, and then everyone has to wait one by one.

[Sykotyk]

Wouldn't a four-way stop be just as dangerous if there were no set manner to enter other than 'whoever gets into the intersection first?'

But that IS the only set manner to enter a four-way-stop. The only time yielding to the right comes in to play at all is when two cars get there at exactly the same time, which is NOT most of the time. And there are some jurisdictions where yielding to the right isn't even codified, but rather a common courtesy.

In other words, there is a set pattern on how to enter a four-way stop intersection, and that pattern is this: Whoever gets there first goes first; if you and the car to your right get there at the same time, then yield to the other driver (that last part may or may not be codified). Similarly, there is a set pattern on how to enter a roundabout: if nobody is imminently approaching on your left, then go on through; if someone is imminently approaching on your left, then yield.

If all four vehicles approach a roundabout at exactly the same time, then nobody has to wait at all: each can safely enter the roundabout because no other car is yet imminently approaching on the left. If all four vehicles approach a four-way stop at exactly the same time, then nobody quite knows who should go first, and then everyone has to wait one by one.

When there's already traffic at the intersection, that last line is exactly how it's done. If there's already two cars ahead of you and a line at the other three approaches, you simply wait your turn. Not trying to remember whether you got to the intersection before someone else and go in that order. You go in the sequential order that's already been started. Counter-clockwise, around and around until eventually the traffic is clear.

At a round-about, there is no traffic pattern or rule other than 'yield to traffic in circle' which leaves a wide breadth as to how much space to yield. You get people gunning it to be the next one in the circle, regardless which 'turn' would've been there's at a stop sign. And then you get followers, who continue with the person in front of them. Which effectively becomes a four-phase traffic light with random phases.

And technically, if you're to yield to traffic in the circle, you have to yield to all traffic in the circle, not just whether you can floor it and get out in time before getting T-boned. Including oncoming traffic. Again, if a roundabout is that congested, it should be cleared out similar to a four-way stop: traffic on the right goes first, counter-clockwise, until all the approaches are clear.

Modern roundabouts that are replacing intersections (small medians, not the large 100-200ft behemoths that I consider traffic circles or rotaries like in the northeast), work best on roads that handle intermittent traffic from all directions when traffic volumes generally don't clog up an intersection.

US 59 & US 169 in Garnett, Kansas is a decent example. Two roads with intermittent traffic. It's not steady from any one approach. It's better than signalized, and a lot better than a stop-sign. It works because the intersection never saw a pressing need for other action (four-lane with a median and at-grade ramp system with stop-signs to break up traffic). Most of the time, you'll approach that traffic circle and be the first to go through without impeding traffic from another direction.

You put that roundabout in a downtown, urban, or suburban setting, and suddenly you get traffic. The roundabout doesn't relieve traffic, it only relieves wait times for a signal. But, enough traffic forces its wait time back to a signalized intersection. One thing roundabouts do, though, is create 'steady flow' for business and sidestreet traffic.

Imagine you're pulling out of a business that's just down the road from a traffic circle in a congested area. You constantly have traffic to deal with. Where, before, in a signalized intersection, you have a light that will temporarily block the flow of traffic before the turn phase begins for the perpendicular approaches.

https://goo.gl/maps/AVixtAFGkg32

Brattleboro, VT exit from I-89 to VT/NH-9 & US5. Don't make the mistake of stopping at the second gas station south (the one not at the roundabout). You will have a bear of a time pulling out as you have, essentially, free-flowing freeway traffic exiting to either US5 or NH-9. Or, the through traffic on US-5. If there were a light, you would have occassional pauses to pull out to make the left back to either the highway, north on US-5 or east on NH-9.

Roundabouts/traffic circles have their place. But, a lot of them are being shoehorned into congested areas where they don't serve the need well.

And a lot of that has to do with how drivers handle them. It's a free-for-all, rather than a traffic-control-device. We've seen it for decades with the YIELD sign at the end of on-ramps. Drivers do not heed them. Hell, there's many drivers you'll come across absolutely irate if you don't yield to the on-ramp traffic. That lack of respect and legality to a yield sign has carried over to the roundabout. That yield sign might as well not exist with how little people respect it.

What they need is to remove the YIELD sign and replace it with a STOP sign and a white regulatory sign underneath that states something along the lines of, "For Traffic In Circle Only" similar in manner to how "Except Right Turn" gets placed under many stop signs where the through line turns right at an intersection.

People, overwhelmingly, respect stop signs compared to yield signs. The lack of enforcement for "Failure To Yield" at a yield sign, anywhere, is astounding. At a stop sign, it's much more enforced. Which leads to compliance.

We can have a million and one 'Don't Text and Drive' or 'Don't Drink and Drive' but not one 'Yield means Yield' campaigns.

[Sykotyk]

How would it jam up the approaches anymore than they already are? More than one can be in a roundabout at the same time. But, only one approach at a time in rotation should get to go.

they must wait until the first car at each other approach also clears the roundabout. And THEN they get to go. Same as a stop sign.

I'm glad you can operate the quote function. Again, 'How would it jam up the approaches anymore than they already are?' If a roundabout were so crowded to have traffic lined up at all four approaches, wouldn't you want traffic to be orderly, or are you content with 'every man for themselves'?

[jeffandnicole]

How would it jam up the approaches anymore than they already are? More than one can be in a roundabout at the same time. But, only one approach at a time in rotation should get to go.

they must wait until the first car at each other approach also clears the roundabout. And THEN they get to go. Same as a stop sign.

I'm glad you can operate the quote function. Again, 'How would it jam up the approaches anymore than they already are?' If a roundabout were so crowded to have traffic lined up at all four approaches, wouldn't you want traffic to be orderly, or are you content with 'every man for themselves'?

I would have them operate the way they operate now, which is generally fine.

[kalvado]

[ Again, 'How would it jam up the approaches anymore than they already are?' If a roundabout were so crowded to have traffic lined up at all four approaches, wouldn't you want traffic to be orderly, or are you content with 'every man for themselves'?

If you have all 4 - or, worse, just 1 leg of roundabout flooded with traffic - you are outside design parameters, and things no longer work. Roundabouts are designed to be a somewhat ordered anarchy, when resources (time in the circle) are not managed, but shared. If one leg grabs 100% of time...
My personal record is sitting 15 minutes waiting for a gap in traffic. After some event was over, circle was flooded with south-to-north bumper to bumper traffic, and I was sitting on the eastern approach without a chance to do anything. Traffic light downstream ensured entire line moved at, or below, 15 MPH, so no gaps at all. I still have to see something like that for general commute, but that is  a probable failure mode for the concept.

[kphoger]

If there's already two cars ahead of you and a line at the other three approaches, you simply wait your turn. Not trying to remember whether you got to the intersection before someone else and go in that order.

Of course not.  But reaching the tail of the line of cars is not the same thing as getting to the intersection.  At a four-way stop, the only thing influencing your decision to go or wait is what's happening at the other three stop signs at that time.  Likewise, the only thing influencing your decision to go or wait is what's happening on your immediate left at that time.  That's what a stop sign means, and that's what a yield sign means.

And special circumstances require special decision-making.  An eighteen-wheeler, for example, can either make for more people going ahead of their turn (because he's very slow and waves you on, or because traffic needs to clear the intersection for his wide turn) or more people having to wait longer (because their line through the intersection has cleared while the truck is still turning, even though they got to the intersection after the cars that are still blocked).  The even traffic mentioned just up-thread by @kalvado should have paused every so often, even within the circulating roadway, to let him in; that's how polite drivers operate at a similar situation at a four-way stop, and that's how they should operate at a roundabout.

Counter-clockwise, around and around until eventually the traffic is clear. * * * Again, if a roundabout is that congested, it should be cleared out similar to a four-way stop: traffic on the right goes first, counter-clockwise, until all the approaches are clear.

Actually, it's not that simple.  It's more efficient for each pair of opposing traffic to proceed at the same time, meaning NB and SB cars proceed through simultaneously, then EB and WB cars proceed through simultaneously, and so on.  In this scenario, four cars get through the intersection in only two "cycles" instead of four cycles.  However, this progression only works until, for example, SB is turning left and NB is turning right, then the sequence gets messed up.  There is no simple, perfect, optimal way of ordering the movements at a four-way stop, because different turning movements create different environments.

At a roundabout, it concerns me not one bit when the driver on the opposite side of the intersection got there or which direction he's going.  All that concerns me is what the driver immediately on my left is doing.

At a round-about, there is no traffic pattern or rule other than 'yield to traffic in circle' which leaves a wide breadth as to how much space to yield. * * * And technically, if you're to yield to traffic in the circle, you have to yield to all traffic in the circle, not just whether you can floor it and get out in time before getting T-boned. Including oncoming traffic.

No more breadth than a yield sign at a simple four-way intersection.  All a yield sign indicates is that you give way to approaching traffic presenting an imminent danger; anything less than imminent is not your concern, because your paths do not conflict.  "Yield to traffic in circle" signage is simply the agency's way of explaining to drivers how a roundabout works, not that they have to wait for the entire circle to clear or some such nonsense.

You get people gunning it to be the next one in the circle, regardless which 'turn' would've been there's at a stop sign. And then you get followers, who continue with the person in front of them. Which effectively becomes a four-phase traffic light with random phases.

These things happen at four-way stops too.  In neither intersection type, though, do followers make it "effectively become a four-phase traffic light with random phases", because those drivers are outliers and do not have any meaningful effect on the performance of the intersection.

Modern roundabouts that are replacing intersections (small medians, not the large 100-200ft behemoths that I consider traffic circles or rotaries like in the northeast), work best on roads that handle intermittent traffic from all directions when traffic volumes generally don't clog up an intersection.

I agree.  I should point out that there are some roundabouts in areas of steady traffic that perform quite well, such as the Skaggs roundabout in Branson, Missouri.  That one is a five-leg roundabout that sees much more traffic on three of its approaches than on the other two, and both local and tourist traffic is a steady flow.  It performs great, and was a welcome replacement of what was there previously.

What I think seriously does a roundabout in is heavy traffic volumes, especially when there are traffic signals nearby.  Traffic tailbacks extending through a roundabout are like death to the intersection. 

US 59 & US 169 in Garnett, Kansas is a decent example. Two roads with intermittent traffic. It's not steady from any one approach. It's better than signalized, and a lot better than a stop-sign. It works because the intersection never saw a pressing need for other action (four-lane with a median and at-grade ramp system with stop-signs to break up traffic). Most of the time, you'll approach that traffic circle and be the first to go through without impeding traffic from another direction.

Excellent example.  A similar four-way roundabout that functions great is the one on US-400 at Fredonia.  Pulling out onto 400 from the side road used to be a dangerous proposition, but now it's much safer without stoplights or stop signs.

You put that roundabout in a downtown, urban, or suburban setting, and suddenly you get traffic. The roundabout doesn't relieve traffic, it only relieves wait times for a signal. But, enough traffic forces its wait time back to a signalized intersection.

Without nearby traffic signals, it should still be no problem.  Again, I think the killer in urban settings is nearby traffic signals.  Red-light tailbacks reaching the circulating roadway render the roundabout inoperable.  I hadn't much considered roundabout tailbacks reaching the stoplight, but that sort of thing happens with two stoplights anyway.  It's easier to get traffic to not block a signalized intersection than it is to get traffic to not block a whole roundabout.

One thing roundabouts do, though, is create 'steady flow' for business and sidestreet traffic.

Imagine you're pulling out of a business that's just down the road from a traffic circle in a congested area. You constantly have traffic to deal with. Where, before, in a signalized intersection, you have a light that will temporarily block the flow of traffic before the turn phase begins for the perpendicular approaches.

This is true.  While it is risky business to plan on a break in heavy traffic due to signal timing (sometimes traffic is heavy enough that you never end up getting that gap you were hoping for), no such large gaps can be planned for with roundabouts.  This isn't a problem if traffic is light enough that small gaps emerge, but it does become a problem if traffic is heavy.  There's no easy way around this.

Roundabouts/traffic circles have their place. But, a lot of them are being shoehorned into congested areas where they don't serve the need well.

This is true.  But it's also true of stop signs and traffic signals, added to locations where a roundabout would serve the need nicely.

And a lot of that has to do with how drivers handle them. It's a free-for-all, rather than a traffic-control-device. We've seen it for decades with the YIELD sign at the end of on-ramps. Drivers do not heed them. Hell, there's many drivers you'll come across absolutely irate if you don't yield to the on-ramp traffic. That lack of respect and legality to a yield sign has carried over to the roundabout. That yield sign might as well not exist with how little people respect it.

As for yielding at an on-ramp merge...  Many jurisdictions don't even put yield signs at then end of the ramps.  Also, it is common courtesy to slow down or move over for merging traffic.  Basically, on-ramps are widely taken as more of a "form one lane" situation than a true yield situation, despite what signage might be present.  And, actually, this is a good thing:  having to come to a full stop upon merging onto a 65-mph highway is a recipe for disaster.

As for heeding yield signs in general, I agree that they are widely ignored, not just at on-ramps as discussed, but more dangerously at simple four-way intersections; drivers slow down so little for a simple yield intersection that, by the time a crossing vehicle comes into view, there's precious little time to actually stop.  But this is not what I've seen at roundabouts.  People approaching roundabouts are already slowing down due to additional signage and curve geometry, which makes them more ready to truly yield.  I honestly hardly ever see drivers blatantly ignoring yield signs at roundabout approaches the way I see them blatantly ignore them at simple four-way intersections.

What they need is to remove the YIELD sign and replace it with a STOP sign and a white regulatory sign underneath that states something along the lines of, "For Traffic In Circle Only" similar in manner to how "Except Right Turn" gets placed under many stop signs where the through line turns right at an intersection.

Disagree.  Trying to fix a few bad drivers' behavior through more imperative signs is not going to solve anything.  What would likely result is a great number of drivers stopping for no reason:  by the time they're read the little white placard, they've already come to a full stop.  And then you'd still be left with your stated dilemma of what "in circle" means.  Will they remain stopped till the whole thing clears?  Etc.

People, overwhelmingly, respect stop signs compared to yield signs. The lack of enforcement for "Failure To Yield" at a yield sign, anywhere, is astounding. At a stop sign, it's much more enforced. Which leads to compliance.

We can have a million and one 'Don't Text and Drive' or 'Don't Drink and Drive' but not one 'Yield means Yield' campaigns.

I'm not sure I've witnessed enough people running a yield sign with a police officer nearby to come to any conclusion about how often it's enforced.  And I'm pretty amazed that you have.  Generally, yield signs are used at low-volume intersections where running one doesn't usually put anyone in jeopardy and, in the case there is actual jeopardy, the chances of a cop being nearby are slim to none.  But whatever.

[Sykotyk]

I've seen it enough in a few places. And I've seen it cropping up at roundabouts. The definition of 'imminent' is the problem. Some drivers are a lot more brazen with their travel into the roundabout than others.

Yes, a STOP w/regulatory sign may cause some to stop without reason. But, there's enough scaredycats that do that as now with yield signs. But, it will slow down the people rolling through unsafely.

The uptick in accidents at these roundabouts is proving that drivers aren't driving properly through them. The issue whether the agencies responsible want to have their heads in the sand, or accept that some drivers simply bugger up the system. Both the timid and the brave.

The thing with signalized or 4-way, was that if you got a green light, your odds of not facing cross-traffic were next-to-nil. Sure, some ran lights. Either inattentive during the phase or the bastards who ran it just as their phase had ended, but it wasn't likely. In a 4-way, the traffic around you at least had to stop (unless, of course, inattentiveness at any point or trying to 'beat' someone through it). But, you had a better understanding of "if car from my left is cruising at 35mph up to a stop sign, and I just stopped at the stop sign, I may pause momentarily to make sure they, too, are stopping. At a yield situation, you're doing that while driving, and that other car may be thinking they can 'time' the roundabout to get through without stopping, or rather slowing down much, if at all.

Which comes down to the yield sign. It doesn't hold the weight in drivers' eyes as the stop sign does. It's the weak little brother to the stop sign.

Part of the allure of roundabouts is no more signals and the associated costs. But, flashing yellows at all approaches that can be turned to metered during heavy-volume situations would work best in major areas with sensors on the exits to show that the vehicle (or vehicles if a 4-way operating in tandem n/s e/w each) have cleared the roundabout.

But, then we'd be better off with a 4-way stop sign with a smaller geographic footprint.