Over 7000 roundabouts in America

[kalvado]

Meh.  NY 85 SB after becoming two lanes to cross the Thruway is not a freeway.

Somehow I think the use of the roundabouts might be a way to get people south of the Thruway to accept four lanes along NY 85, even if it isn't.

OT, I think I see a few makeshift exit ramp parts at some intersections in Voorheesville on GSV at places like Clipp Road and the vicinity of Helderhill Road.

The bypass has been a great improvement.  The light at Blessing Road was horrendous and almost seemed unnecessary; the roundabout there has been most welcome.  Getting through the lights on New Scotland was annoying and, although there were quite a number of fender benders due to human error at the get-go, I haven't seen an accident at the NY 85/NY 140 roundabout in a very long time (tradephoric likes to focus on the accident-prone transition period and ignore when accident dropoffs happen at those same sites).

So, I don't know how much the roundabouts were for convincing Bethlehem that four lanes were needed as much as it was built to address the congestion and to allow some commercial development (although I can't imagine that Shop Rite is doing very well from the traffic I see).

The Clipp Road thing is just a private pullout (you can see the property signs on the trees).  Same goes for Helderhill.

Bypass was a great improvement in terms of rerouting 85 and not dumping all that traffic on New Scotland.
In terms of development - I believe that SHopRite is still the only larger tenant in Vista Technology Campus.
Roundabouts... well, replacing "no turn on red" woth some merge lanes can also go a long way. And those roundabouts were at the top of crash lists for quite a while. Probably long enough so that total elimination of crashes for next 20 years wouldn't brake it even.
My bet  is everyone would be better off if instead of roundabouts, rehabilitation off northern stretch of 85 was funded back then. Would definitely save a few suspensions.

[D-Dey65]

The Clipp Road thing is just a private pullout (you can see the property signs on the trees).  Same goes for Helderhill.

Oh, I thought those were temporary Jersey Freeway-type ramps that were planned to be upgraded. My bad.


The one west of Helderhill looks like an on-ramp from nowhere.

[tradephoric]

The problem with the old thread and now, predictably this one, are the videos and stories handpicked to attempt to put roundabouts in a bad light. If someone drives at 60 mph strait through a roundabout the design and theory behind the intersection is not at fault. No one makes an argument that plowing through a red light means traffic light-controlled intersections are inherently dangerous. Pixel 2

The generalization has been that roundabouts are safe and traffic signals are dangerous.  However, studies published over the past couple years have found that there are safety issues with multi-lane roundabouts.  The multi-lane roundabouts analyzed in the Minnesota study saw a 6% increase in injury crashes compared to the conventional intersections they replaced. 

The generalization that all roundabouts are safe (whether they be single-lane or multi-lane) is largely based on the IIHS study back from 2000.  As I have mentioned before, only 5 roundabouts along a 2500 foot section of Avon Road in Colorado was analyzed for injury crashes - not to mention Avon Road is only signed for 25 mph.  Yet the safety statistics found in that IIHS study (ie. 35% reduction in all crashes, 76% reduction in injury crashes, 90% reduction in fatal crashes) has been cited countless times by agencies to justify the construction of complex 2x2 and 3x2 roundabouts throughout America... and those types of roundabouts have really exploded over the past decade.  Today there are about 50 triple-lane modern roundabouts whereas 20 years ago there were zero.  The truth is those triple-lane roundabouts have been somewhat of a disaster in this country.  Many triple-lane modern roundabouts have been downsized years after being constructed.  The roundabouts that haven't been downsized are the ones where you see 150+ crashes/year.  But roundabouts are safe and traffic signals are dangerous... after all that IIHS study is 'settled science'. 

[billpa]

* You never differentiate between single and multi-lane roundabouts until you're pressed.

* Your arguments would go down better with people like me if you did away with the ridiculous videos and stories of crashes 'related' ( usually just near ) to roundabouts which a cursory read reveal are actually caused by things like excessive speed and drunk driving.

* I never said anything negative about traffic-lighted intersections. My point is I could start a silly thread about traffic light junctions with news stories about crashes that occurred in them. It wouldn't prove much if the offending driver was wasted or driving at 50 mph when the light was red.

Pixel 2

[TheHighwayMan3561]

* Your arguments would go down better with people like me if you did away with the ridiculous videos and stories of crashes 'related' ( usually just near ) to roundabouts which a cursory read reveal are actually caused by things like excessive speed and drunk driving.

I'm pretty sure at least once he did fault a roundabout when a drunk speeder launched himself airborne through the center of a roundabout, saying the dude may have been safe if it was a standard signalized intersection - ignoring that whole drunk and speeding thing.

[silverback1065]

* You never differentiate between single and multi-lane roundabouts until you're pressed.

* Your arguments would go down better with people like me if you did away with the ridiculous videos and stories of crashes 'related' ( usually just near ) to roundabouts which a cursory read reveal are actually caused by things like excessive speed and drunk driving.

* I never said anything negative about traffic-lighted intersections. My point is I could start a silly thread about traffic light junctions with news stories about crashes that occurred in them. It wouldn't prove much if the offending driver was wasted or driving at 50 mph when the light was red.

Pixel 2

roundabouts trigger him so he finds random articles to confirmation bias him into hating them more.  numbers speak for themselves, the accidents they do have tend to be less severe than traditional ones.  a lot of accidents come from people who have no idea what they are doing in one, I can't tell you how many times people try to make a left turn from the right lane in a roundabout.  there is sufficient signage and pavement markings that make this inexcusable.   

[tradephoric]

* You never differentiate between single and multi-lane roundabouts until you're pressed.

I just did a forum search and I referred to "˜complex multi-lane' roundabouts in 24 separate posts.  I keep saying the phrase "complex multi-lane"  because it not only distinguishes between single-lane and multi-lane, but it also distinguishes between simplified 1x2 multi-lane roundabouts and the complex 2x2 or 2x3 types.  In one post I attempted to explain why I feel there is a fundamental crash problem at 2x2 roundabouts that you don't see at 1x2 types.   
 

Take a look at these two pictures below.  In both cases the yellow car assumes the blue car in the inner-most lane of the roundabout will continue circulating through the roundabout ("the circular road misconception" ).  With a 2x2 roundabout the assumption can lead to a crash when the blue car actually takes the red path.    However, with a 1x2 roundabout this assumption by the yellow driver doesn't lead to a crash since both paths the blue car can take is in conflict with the yellow car (so the yellow car is forced to wait regardless.. since it's tough to squeeze two cars into one lane).



This is a fundamental problem I see with 2x2 roundabouts.  How do you design 2x2 roundabouts so the driver in the yellow car knows that the blue car may actually be exiting the roundabout?  In too many cases the yellow car wrongfully assumes the blue car is going to continue circulating around the roundabout and pulls out... leading to a failure to yield crash.

[tradephoric]

* Your arguments would go down better with people like me if you did away with the ridiculous videos and stories of crashes 'related' ( usually just near ) to roundabouts which a cursory read reveal are actually caused by things like excessive speed and drunk driving.

I'm pretty sure at least once he did fault a roundabout when a drunk speeder launched himself airborne through the center of a roundabout, saying the dude may have been safe if it was a standard signalized intersection - ignoring that whole drunk and speeding thing.

The IIHS study from 20 years ago found that roundabouts reduce injury crashes by 76%.  Then a study from 2 years ago looking specifically at 2x2 multi-lane roundabouts found that injury crashes increased by 6% compared to the intersection they replaced.  Maybe i missed it, but i don't remember either study saying "drunk driving accidents" were ignored in the study.  If that's the case I don't really care if Bozo the clown walked into the middle of the roundabout, causing someone to swerve and crash.  According to these studies, a crash is a crash is a crash.  The ultimate question is do roundabouts reduce injury crashes compared to signalized intersections.  At the very least, there seems to be a subset of modern roundabouts (ie. 2x2 or 2x3 types) where the answer may be NO.

[kphoger]

numbers speak for themselves, the accidents they do have tend to be less severe than traditional ones.

↓  "Numbers" are saying more than just one thing.  ↓

a study from 2 years ago looking specifically at 2x2 multi-lane roundabouts found that injury crashes increased by 6% compared to the intersection they replaced.

[froggie]

For the study that tradephoric keeps referencing (yes I read through it), one could argue that the lack of multi-lane roundabouts studied (only 6) could be introducing a bias into the results because of the small sample size.  Very unlike the number of single-lane roundabouts studied (over 100) and unbalanced roundabouts (over 30).

It's also worth noting that, despite the small sample size of multi-lane roundabouts, none of them produced a fatality or serious injury.

[kalvado]

For the study that tradephoric keeps referencing (yes I read through it), one could argue that the lack of multi-lane roundabouts studied (only 6) could be introducing a bias into the results because of the small sample size.  Very unlike the number of single-lane roundabouts studied (over 100) and unbalanced roundabouts (over 30).

It's also worth noting that, despite the small sample size of multi-lane roundabouts, none of them produced a fatality or serious injury.

Frankly speaking, there are only that many studies of roundabouts in US. Europe seems to have a bigger pool of studies with way better understanding of do's and donot's.

[tradephoric]

For the study that tradephoric keeps referencing (yes I read through it), one could argue that the lack of multi-lane roundabouts studied (only 6) could be introducing a bias into the results because of the small sample size.  Very unlike the number of single-lane roundabouts studied (over 100) and unbalanced roundabouts (over 30).

The 6 multi-lane roundabouts analyzed in the Minnesota study provided 668 data points (197 crashes in the before condition; 471 crashes in the after condition).  In addition, the IIHS study that generic roundabout safety statistics are based on only analyzed 5 multi-lane roundabouts that included before/after injury crash data.  If you want to be critical of the small number of multi-lane roundabouts in the Minnesota study you should also be critical of the small number of multi-lane roundabouts analyzed in the IIHS study.

It's also worth noting that, despite the small sample size of multi-lane roundabouts, none of them produced a fatality or serious injury.

Yet they produced 7 more Level-C crashes and a whopping 270 more PDO crashes.  It's great that there were 0 Type-A crashes, but if we use FHWA's comprehensive crash costs by injury severity level it's still clear that the roundabouts had a higher social cost than the intersections they replaced.


http://www.dot.state.mn.us/trafficeng/safety/docs/roundaboutstudy.pdf

BEFORE ROUNDABOUT CRASH COSTS = $4,882,600
Fatality (K)           0 X $4,008,900 = $0
Disabling Injury (A)   3 X  $216,000 = $648,000
Evident Injury (B)   15 X $79,000 = $1,185,000
Possible Injury (C)   46 X $44,900 = $2,065,400
PDO (O)          133 X $7,400 =  $984,200

AFTER ROUNDABOUT CRASH COSTS = $6,546,900
Fatality (K)           0 X $4,008,900 = $0
Disabling Injury (A)   0 X  $216,000 = $0
Evident Injury (B)   15 X $79,000 = $1,185,000
Possible Injury (C)   53 X $44,900 = $2,379,700
PDO (O)          403 X $7,400 =  $2,982,200

[TheHighwayMan3561]

* You never differentiate between single and multi-lane roundabouts until you're pressed.

I just did a forum search and I referred to "˜complex multi-lane' roundabouts in 24 separate posts.  I keep saying the phrase "complex multi-lane"  because it not only distinguishes between single-lane and multi-lane, but it also distinguishes between simplified 1x2 multi-lane roundabouts and the complex 2x2 or 2x3 types.  In one post I attempted to explain why I feel there is a fundamental crash problem at 2x2 roundabouts that you don't see at 1x2 types.   
 

Take a look at these two pictures below.  In both cases the yellow car assumes the blue car in the inner-most lane of the roundabout will continue circulating through the roundabout ("the circular road misconception" ).  With a 2x2 roundabout the assumption can lead to a crash when the blue car actually takes the red path.    However, with a 1x2 roundabout this assumption by the yellow driver doesn't lead to a crash since both paths the blue car can take is in conflict with the yellow car (so the yellow car is forced to wait regardless.. since it's tough to squeeze two cars into one lane).



This is a fundamental problem I see with 2x2 roundabouts.  How do you design 2x2 roundabouts so the driver in the yellow car knows that the blue car may actually be exiting the roundabout?  In too many cases the yellow car wrongfully assumes the blue car is going to continue circulating around the roundabout and pulls out... leading to a failure to yield crash.

Correct me if I'm wrong, but doesn't "yield"  actually mean "yield"  and not "yield only if I'm going to get in the way" ? One of my pet peeves is cars with a stop/yield sign who turn into the right lane while I'm simultaneously in the left lane because I don't know if he's going to make a wide turn or slip on ice into me or some other stupid shit because he's too impatient to wait a few seconds. Conversely if I'm the one at the sign I don't know if he's going to change lanes abruptly or something either.

[kalvado]

Correct me if I'm wrong, but doesn't "yield"  actually mean "yield"  and not "yield only if I'm going to get in the way" ? One of my pet peeves is cars with a stop/yield sign who turn into the right lane while I'm simultaneously in the left lane because I don't know if he's going to make a wide turn or slip on ice into me or some other stupid shit because he's too impatient to wait a few seconds. Conversely if I'm the one at the sign I don't know if he's going to change lanes abruptly or something either.

I cannot find legal definition at the moment - but as far as I remember, "yield" means that other traffic should be able to move without changing speed or intentions as if yielding vehicle is not there.
SO a car going into a different direction, or into a different lane is OK - as long as turning into a different lanes is actually required (which is another pile of fine print)

[silverback1065]

if you reach a yield sign, you YIELD the r/w to opposing traffic. hence the name

[jakeroot]

if you reach a yield sign, you YIELD the r/w to opposing traffic. hence the name

Right but you don't need to yield to traffic that shouldn't interfere with you.

[Plutonic Panda]

if you reach a yield sign, you YIELD the r/w to opposing traffic. hence the name

Right but you don't need to yield to traffic that shouldn't interfere with you.

If only more people understood this!

[english si]

In one post I attempted to explain why I feel there is a fundamental crash problem at 2x2 roundabouts that you don't see at 1x2 types.

As I pointed out at the time, this particular crash problem only is as bad as it is because of the idea that it is a circular road is a fallacy - which comes from one influential, but idiotic, engineer.

In regards to using a signal indication when exiting a roundabout... that was actually being discouraged by the roundabout expert in the Minnesota webinar:

"We also would never tell a driver to use a right turn signal to exit a roundabout.  Again, that's a through movement and we don't want to create the impression that it's a right turn."

If the blue car's blinkers were being used to announce where it was going, then the yellow car's driver wouldn't be confused. Which is how it is meant to work in the UK...

This is a fundamental problem I see with 2x2 roundabouts.  How do you design 2x2 roundabouts so the driver in the yellow car knows that the blue car may actually be exiting the roundabout?  In too many cases the yellow car wrongfully assumes the blue car is going to continue circulating around the roundabout and pulls out... leading to a failure to yield crash.

Design it as an ACTUAL circular road, and so exiting the roundabout requires indication (using your blinkers) to follow the rules of the road (eg 186, which is the British rule governing these matters) as you are turning off it!

[kalvado]

if you reach a yield sign, you YIELD the r/w to opposing traffic. hence the name

Right but you don't need to yield to traffic that shouldn't interfere with you.

If only more people understood this!

Problem of many roundabouts is that there are a lot of situations where interference is not clear until traffic either passes (and you didn't have to yield), or you did have to yield - but it is a property-damage only now, don't worry.

And the thing is that the driver in a white car cannot see blue car blinkers. Not a problem if the circle is big enough so that there is time to pass.
But many supermicrocompact circles are squeezed into existing intersections, so white car has to wait until blue one actually exits.

[tradephoric]

And the thing is that the driver in a white car cannot see blue car blinkers. Not a problem if the circle is big enough so that there is time to pass.  But many supermicrocompact circles are squeezed into existing intersections, so white car has to wait until blue one actually exits.

The A roundabout pictured below has a central island diameter of about 80 feet while the B roundabout has a diameter of about 100 feet.  Even though the A roundabout is more compact, the design of "straight out" exits helps separate traffic between each leg of the roundabout.




And here's a redesign i made up of a crash prone triple-lane roundabout in Michigan.  The same idea applies here with separating legs of traffic with "straight out" exits.  Also designing the central island to be more "rectangular" than circular i believe could be beneficial.

[tradephoric]

The bypass has been a great improvement.  The light at Blessing Road was horrendous and almost seemed unnecessary; the roundabout there has been most welcome.  Getting through the lights on New Scotland was annoying and, although there were quite a number of fender benders due to human error at the get-go, I haven't seen an accident at the NY 85/NY 140 roundabout in a very long time (tradephoric likes to focus on the accident-prone transition period and ignore when accident dropoffs happen at those same sites).

Actual crash data would make any argument you are trying to make more powerful.  You personally not seeing a roundabout accident in a very long time just doesn't cut it.  Here is a list of the 20 most crash prone intersections in Michigan in 2017.

https://www.freep.com/story/news/local/michigan/2018/05/11/michigan-most-dangerous-intersections/602137002/

The triple-lane roundabouts at 18 1/2 and Van Dyke (constructed about 15 years ago now) is the #2 most crash prone intersection in Michigan... and it doesn't come close to carrying an extensive amount of traffic to justify that high ranking.  That just happens to be the roundabout i attempted to redesign in the previous post.  The other triple-lane roundabouts in Michigan are #4 and #5 on that list.  There use to be 7 triple-lane roundabouts in Michigan, but 4 of them were downsized to 2x2.  The 3 that remain have horrible crash rates. 

[Rothman]

Oh, so despite my very routine trips up and down those roundabouts, you think all the crashes I saw are just happening at the same rate at different times of the day?  That is less powerful, actually.  At least I have my observations.  You don't even have that in your rebuttal regarding NY 85.

I also suspect that since you were able to find crash statistics on the NY 85/NY 140 shortly after the roundabout opened and you touted it's high crash rate that your refusal to look into that particular data again may be evidence of data cherry picking to support your crusade.

[Paulinator66]

Actual roundabouts, or just little bitty islands in the middle of the intersections?

While travelling in Ireland last year there were roundabouts everywhere, as you would expect, but there was one intersection that was so small there was simply a 2 foot diameter circle painted in the middle of an otherwise normal looking American intersection.  I still drove around it though.

[abefroman329]

Actual roundabouts, or just little bitty islands in the middle of the intersections?

While travelling in Ireland last year there were roundabouts everywhere, as you would expect, but there was one intersection that was so small there was simply a 2 foot diameter circle painted in the middle of an otherwise normal looking American intersection.  I still drove around it though.

It's known as a mini-roundabout, and they're pretty common in the UK.  I think the principle is "yield to whoever is in the intersection before proceeding," since there's really no way to traverse the intersection in a circular fashion.

[kalvado]

Oh, so despite my very routine trips up and down those roundabouts, you think all the crashes I saw are just happening at the same rate at different times of the day?  That is less powerful, actually.  At least I have my observations.  You don't even have that in your rebuttal regarding NY 85.

I also suspect that since you were able to find crash statistics on the NY 85/NY 140 shortly after the roundabout opened and you touted it's high crash rate that your refusal to look into that particular data again may be evidence of data cherry picking to support your crusade.

Crash data is difficult to come by. It usually comes as "worst intersections in the area"
At that point, 85's circles made the list, so data was readily available. I don't know where to look for those numbers outside of querying DOT, police or someone else along those lines.
Traffic counts are there for everyone to look at (fun fact: data on I-81 viaduct area is no longer there); accidents are not.
Actually you may have a better idea where to start.