Crash prone 'modern roundabouts'

[kalvado]

What is known as the Suicide Circle, this roundabout is currently undergoing a big face-lift. I drive through it everyday now since I moved and this project is pretty expansive. It involves completely redoing the roundabout to more safer standards, turning a local business street (State) into a boulevard, and redoing the intersection of State street with Northwest Highway (US-14) to the south.

OG roads before construction: https://www.google.com/maps/@42.0527219,-87.9097305,376m/data=!3m1!1e3

Plan for the circle (Before and after): http://hbmengineering.com/blog/transportation-design/cumberland-circle-roundabout/

I suspect when you have a five-way busy spot, you only choose between bad and worse..
An interesting thing, though is that northbound N. Wolf to southbound north Broadway used to have a separate slip lane, but no such lane and only high angle turn in a new design.. If traffic along that movement warranted extra lane, it may become a hot spot.

[tradephoric]

According to the article below there have been 421 accidents at the Cumberland Circle between 2005 and 2011, with 10% of them involving injury.  So the circle has averaged about 60 total crashes and 6 injury crashes per year. 

Cumberland Circle reconstruction in Des Plaines beginning soon
https://www.dailyherald.com/news/20180330/cumberland-circle-reconstruction-in-des-plaines-beginning-soon

It will be interesting to see if the new roundabout design will help reduce the total number of crashes at the circle.  One of the biggest changes to the operation is that the circle will go from stop controlled at all legs to yield-control.   In addition, it appears the central island will have a larger diameter with the addition of the truck apron.  Will the larger diameter of the circle be beneficial or not?  I know some people on this thread have suggested that modern roundabouts should be stop controlled and that the circle itself should be largely void of pavement markings so that the drivers regulate themselves through the circle.  This is largely what you see at the Cumberland Circle yet it appears to have a significant number of crashes each year. 

I'm of the mindset that it doesn't seem to matter what design is tried at these multi-lane circles... big vs. small... pavement markings vs. no markings... stop controlled vs. yield controlled... drivers just seem to have trouble negotiating through these multi-lane circles without crashing into each other.  One of the biggest reasons i feel this way is because i have yet to find a 2x2 multi-lane roundabout in America that has a crash rate below 1.0 MEV (which is still higher than the average crash rate of a signalized intersection).  There are plenty of different multi-lane roundabout designs out there, yet the best performing multi-lane roundabouts in this country still have higher crash rates than just an average signalized intersection.  Then you have multi-lane roundabouts like the ones along 116th in Carmel that have crash rates 20x higher than a typical signalized intersection.    Multi-lane roundabouts just seem to equate to lots of crashes,  no matter what is tried.

[ET21]

The larger apron could be a result of the increased truck and bus usage on this circle. Dayton Freight Lines has a terminal just on the other side of Northwest Highway and Pace's north suburban garage is right down from the circle on Northwest Highway. Large semis tended to have to use both lanes to navigate the original circle. Plus the circle is one of two ways to access Golf Road, a busy east-west roadway.

I never had issues with the circle before construction began as I already knew how to use roundabouts as I always have to use one going over to a friends house in Sugar Grove on Dugan Road. But I can definitely say that drivers do not know how to use this circle. They'd dart last minute from the left lane to their exit which could either cause or almost cause accidents. They never understood to just make the circle again to come back around.

[kalvado]

The larger apron could be a result of the increased truck and bus usage on this circle. Dayton Freight Lines has a terminal just on the other side of Northwest Highway and Pace's north suburban garage is right down from the circle on Northwest Highway. Large semis tended to have to use both lanes to navigate the original circle. Plus the circle is one of two ways to access Golf Road, a busy east-west roadway.

I never had issues with the circle before construction began as I already knew how to use roundabouts as I always have to use one going over to a friends house in Sugar Grove on Dugan Road. But I can definitely say that drivers do not know how to use this circle. They'd dart last minute from the left lane to their exit which could either cause or almost cause accidents. They never understood to just make the circle again to come back around.

Are you sure you actually understand roundabout operation if you complain about traffic exiting from left lane?

[ET21]

The larger apron could be a result of the increased truck and bus usage on this circle. Dayton Freight Lines has a terminal just on the other side of Northwest Highway and Pace's north suburban garage is right down from the circle on Northwest Highway. Large semis tended to have to use both lanes to navigate the original circle. Plus the circle is one of two ways to access Golf Road, a busy east-west roadway.

I never had issues with the circle before construction began as I already knew how to use roundabouts as I always have to use one going over to a friends house in Sugar Grove on Dugan Road. But I can definitely say that drivers do not know how to use this circle. They'd dart last minute from the left lane to their exit which could either cause or almost cause accidents. They never understood to just make the circle again to come back around.

Are you sure you actually understand roundabout operation if you complain about traffic exiting from left lane?

I'm not complaining.... I'm just stating what I see when I enter it and it is one of the main causes of accidents with it

[kalvado]

The larger apron could be a result of the increased truck and bus usage on this circle. Dayton Freight Lines has a terminal just on the other side of Northwest Highway and Pace's north suburban garage is right down from the circle on Northwest Highway. Large semis tended to have to use both lanes to navigate the original circle. Plus the circle is one of two ways to access Golf Road, a busy east-west roadway.

I never had issues with the circle before construction began as I already knew how to use roundabouts as I always have to use one going over to a friends house in Sugar Grove on Dugan Road. But I can definitely say that drivers do not know how to use this circle. They'd dart last minute from the left lane to their exit which could either cause or almost cause accidents. They never understood to just make the circle again to come back around.

Are you sure you actually understand roundabout operation if you complain about traffic exiting from left lane?

I'm not complaining.... I'm just stating what I see when I enter it and it is one of the main causes of accidents with it

What I am specifically referring to is this phrase

But I can definitely say that drivers do not know how to use this circle. They'd dart last minute from the left lane to their exit which could either cause or almost cause accidents. They never understood to just make the circle again to come back around.

From the look at the map, it is pretty obvious that exiting  from left lane is a standard way of using this circle, look at traces from 5o'clock to 12 o'clock position on the image below. Many roundabouts are actually designed that way; new design renderings show just that as well.


So my question still stands - why do you think you  know how to use this circle?

[ET21]

Because I haven't been involved in such an accident after witnessing a few happen right in front of me due to this very movement. It's not rocket science to use a roundabout, but unfortunately it is to many motorists I encounter on my daily commute.

If you're assuming I'm full of shit why would I lie about something as trivial as knowledge of roundabout movements on an internet forum   

[jeffandnicole]

Because I haven't been involved in such an accident after witnessing a few happen right in front of me due to this very movement. It's not rocket science to use a roundabout, but unfortunately it is to many motorists I encounter on my daily commute.

If you're assuming I'm full of shit why would I lie about something as trivial as knowledge of roundabout movements on an internet forum   

It's pretty clear you do not understand how a roundabout works.

Once you've entered a roundabout, you're not supposed to change lanes.  Signage prior to the roundabout is supposed to inform you which lane you're in for the exit you want.  In many cases, on 2 lane roundabouts, the left lane entering the roundabout places you on the inside of the roundabout, but will guide you out of the roundabout at the appropriate time. 

For roundabouts such as the one pictured, it's not really a modern roundabout, but rather a traffic circle.  And honestly, they tend to have their own rules that aren't going to be found in any rulebook.  For those, you just do what the Romans do, rather than trying to inflict your opinion of how the circle should operate on everyone else.

[ET21]

Because I haven't been involved in such an accident after witnessing a few happen right in front of me due to this very movement. It's not rocket science to use a roundabout, but unfortunately it is to many motorists I encounter on my daily commute.

If you're assuming I'm full of shit why would I lie about something as trivial as knowledge of roundabout movements on an internet forum   

It's pretty clear you do not understand how a roundabout works.

Once you've entered a roundabout, you're not supposed to change lanes.  Signage prior to the roundabout is supposed to inform you which lane you're in for the exit you want.  In many cases, on 2 lane roundabouts, the left lane entering the roundabout places you on the inside of the roundabout, but will guide you out of the roundabout at the appropriate time. 

For roundabouts such as the one pictured, it's not really a modern roundabout, but rather a traffic circle.  And honestly, they tend to have their own rules that aren't going to be found in any rulebook.  For those, you just do what the Romans do, rather than trying to inflict your opinion of how the circle should operate on everyone else.

Thank you for clearing that up  I always just treated it as a roundabout, but your explanation makes sense. Long story short, hope this construction project will improve the flow 

[kalvado]

Because I haven't been involved in such an accident after witnessing a few happen right in front of me due to this very movement. It's not rocket science to use a roundabout, but unfortunately it is to many motorists I encounter on my daily commute.

If you're assuming I'm full of shit why would I lie about something as trivial as knowledge of roundabout movements on an internet forum 

Why, there is no lies. I am treating this as an honest mistake on your side. Fact that you didn't get into an accident doesn't tell you know the drill - it may also be your luck and skill of people around you..
But back to technical matters:
Exit from inner lanes is an essencial design feature of roundabouts.
Old facioned circles can be different, though. Still the circle we're talking about, while not a "modern roundabout", but it is clearly setup to allow exit from left lane on 2 out of 5 legs.
A such, I would take your complain for "exit from no-exit lane", or "exit from left lane where that is not allowed" - but a plain "exit from left lane", combined with confusion between traffic circle and roundabout (later is a special case of a circle in common terminology) raises some red flags.

I never had issues with the circle before construction began as I already knew how to use roundabouts as I always have to use one going over to a friends house in Sugar Grove on Dugan Road. But I can definitely say that drivers do not know how to use this circle. They'd dart last minute from the left lane to their exit which could either cause or almost cause accidents. They never understood to just make the circle again to come back around.

[kalvado]

Because I haven't been involved in such an accident after witnessing a few happen right in front of me due to this very movement. It's not rocket science to use a roundabout, but unfortunately it is to many motorists I encounter on my daily commute.

If you're assuming I'm full of shit why would I lie about something as trivial as knowledge of roundabout movements on an internet forum   

It's pretty clear you do not understand how a roundabout works.

Once you've entered a roundabout, you're not supposed to change lanes.  Signage prior to the roundabout is supposed to inform you which lane you're in for the exit you want.  In many cases, on 2 lane roundabouts, the left lane entering the roundabout places you on the inside of the roundabout, but will guide you out of the roundabout at the appropriate time. 

For roundabouts such as the one pictured, it's not really a modern roundabout, but rather a traffic circle.  And honestly, they tend to have their own rules that aren't going to be found in any rulebook.  For those, you just do what the Romans do, rather than trying to inflict your opinion of how the circle should operate on everyone else.

The old circle seems to be primarily driven between N. Wolf and Golf roads, and pavement marks - both white lines and tire wear lines - show that inner lane exits at those arm. Poor souls trying to take a different trajectory.. Indeed they have a choice of either suddenly exiting from left lane, or having their path crossed by someone exiting from inner lane (as designed). No surprise about nickname!

What is known as the Suicide Circle,

[tradephoric]

This newly built Walker roundabout has been a problem from day one.  Traffic backing up onto the freeway worse than before the roundabout was built has been reported by the Walker Police.  And according to the police there has been an average of 1 crash every 1.7 days since the roundabout opened.

See Walker's new I-12 roundabout in action; residents, police call it 'confusing'
https://www.theadvocate.com/baton_rouge/news/communities/livingston_tangipahoa/article_6d52d828-d611-11e7-9582-8f8dcc4fe95f.html

IT'S A TRAP | Walker roundabouts recording an accident once every two days
https://www.livingstonparishnews.com/news/it-s-a-trap-walker-roundabouts-recording-an-accident-once/article_9d856868-ac70-11e8-a38d-a7be895c7bfd.html

Looking at the aerial of the roundabout there are significant problems with the lane markings.  If they can't get simple pavement markings right my confidence of this roundabout design is low. 



   

[kalvado]

This newly built Walker roundabout has been a problem from day one.  Traffic backing up onto the freeway worse than before the roundabout was built has been reported by the Walker Police.  And according to the police there has been an average of 1 crash every 1.7 days since the roundabout opened.

See Walker's new I-12 roundabout in action; residents, police call it 'confusing'
https://www.theadvocate.com/baton_rouge/news/communities/livingston_tangipahoa/article_6d52d828-d611-11e7-9582-8f8dcc4fe95f.html

IT'S A TRAP | Walker roundabouts recording an accident once every two days
https://www.livingstonparishnews.com/news/it-s-a-trap-walker-roundabouts-recording-an-accident-once/article_9d856868-ac70-11e8-a38d-a7be895c7bfd.html

Looking at the aerial of the roundabout there are significant problems with the lane markings.  If they can't get simple pavement markings right my confidence of this roundabout design is low. 

Well, the top image in a first link shows something that looks like a roadwork on one of erroneous arrows. Maybe they will paint in over?....

[jeffandnicole]

This newly built Walker roundabout has been a problem from day one.  Traffic backing up onto the freeway worse than before the roundabout was built has been reported by the Walker Police.  And according to the police there has been an average of 1 crash every 1.7 days since the roundabout opened.

See Walker's new I-12 roundabout in action; residents, police call it 'confusing'
https://www.theadvocate.com/baton_rouge/news/communities/livingston_tangipahoa/article_6d52d828-d611-11e7-9582-8f8dcc4fe95f.html

IT'S A TRAP | Walker roundabouts recording an accident once every two days
https://www.livingstonparishnews.com/news/it-s-a-trap-walker-roundabouts-recording-an-accident-once/article_9d856868-ac70-11e8-a38d-a7be895c7bfd.html

Looking at the aerial of the roundabout there are significant problems with the lane markings.  If they can't get simple pavement markings right my confidence of this roundabout design is low. 

In this case, it's just a bad design all the way around.  Bad design, bad land markings, bad striping. Coming from the south, the lane marking show that you should use the left land going into the roundabout to make a left turn.  Except, there's no reason to make a left turn.  Most roundabouts aren't signed to show how to make a U-turn, which would be the only reason one would turn left in the roundabout from the south in this case.  In fact, there doesn't seem to be much need for a roundabout design at all, because the top loop doesn't serve any purpose expect to make that U-turn, which doesn't appear to be necessary.

The newspaper story's excuse that traffic will be better once the other roundabout is open doesn't seem very factual either, because there's no congestion going across the bridge.

Since this story was from 2017, I'd think the other roundabout has been opened by now.

[jakeroot]

The satellite imagery probably shows a point in time where the right lane was not open, so the left lane was painted to indicate that continuing back onto the freeway, as well as turning left, was permitted from that lane (whereas, in normal operation, only a left turn should be permitted, since that's supposed to be a double left).

That all said, the "path overlap" appears to be a pretty serious issue. Perhaps reducing the left turns to one lane instead of two would be better. Ultimately, the engineers should have aligned that off-ramp better. Or, they should have moved the roundabouts closer to the bridge, allowing the off-ramps to point straight at the roundabout, instead of coming in at an angle.

[tradephoric]

Minnesota truck drivers reveal their thoughts about the notorious roundabouts in Worthington, which has been the site of at least four confirmed truck tip-overs over the past year (all of which have been documented in this thread).  It just doesn't seem roundabout designers consider all the factors that truck drivers must deal with:

Risky roundabouts? Area truck drivers share thoughts about circular junctions
https://www.dglobe.com/news/traffic-and-construction/4494568-risky-roundabouts-area-truck-drivers-share-thoughts-about

"You're top heavy, so you hit that impact curb and it tips the truck,"  Schutte said.

Add in heavy winds, and these combined factors could easily cause the trailer to roll over, said Gary Abels, a Brewster semi driver and owner of Abels Transport. In addition to tipping, the truck apron can cause hang-up issues if the trailer has low ground clearance.

"My trailer is only four inches off the ground when it's heavy, so then I have to avoid the apron,"  Abels said.

On one occasion, Abels was forced to avoid Worthington roundabouts entirely. Delivering a planter to Worthington Ag Parts, he was not allowed to travel through the roundabout due to an oversized load, per state law.

"That's another issue,"  Abels said. "Trucks with oversized trailers can make normal turns, but they can't go through roundabouts, so how are we supposed to get into town if they build even more roundabouts?"

[jeffandnicole]

This roundabout in Trenton, NJ has a flat apron. https://goo.gl/maps/9AcB1PdPNa12  The result is that many people drive straight across it rather than properly go around it.

A long-time issue with truckers at normal intersections is they can't make the turn without cutting out into a same-direction lane or opposing lane of traffic.  Accidents have resulted with this as well. 

Oversized trailers must receive a permit and routing information prior to travel, so any issues with obstructions, including undersized height bridges, weight restricted bridges, and other obstacles, like roundabouts, are taken into account with the routing.  If these truckers are in areas where bridges aren't an issue, they're lucky.  Truckers in the NYC area will laugh at their issue with a little roundabout when they're dealing nonstop with the obstructions they face everyday.

[kalvado]

This roundabout in Trenton, NJ has a flat apron. https://goo.gl/maps/9AcB1PdPNa12  The result is that many people drive straight across it rather than properly go around it.

A long-time issue with truckers at normal intersections is they can't make the turn without cutting out into a same-direction lane or opposing lane of traffic.  Accidents have resulted with this as well. 

Oversized trailers must receive a permit and routing information prior to travel, so any issues with obstructions, including undersized height bridges, weight restricted bridges, and other obstacles, like roundabouts, are taken into account with the routing.  If these truckers are in areas where bridges aren't an issue, they're lucky.  Truckers in the NYC area will laugh at their issue with a little roundabout when they're dealing nonstop with the obstructions they face everyday.

After all it is about roundabouts niche.
They are not for truck-heavy roads, that's what you're saying. That actually came up a few times upstream - roundabouts good for cars, not for something bigger.
Fine with me.  That would quickly exclude any moderately busy road  - US/state fall out automatically, as well as anything close to freeway exits. Two lane to two lane at most...
If that is the limitation to be imposed on any roundabout construction - I think there is no need to ban them through act of Congress..

[tradephoric]

Van FLIES over roundabout in shocking video - three injured as police launch probe
https://www.express.co.uk/news/uk/1017199/norfolk-news-attleborough-a11-van-roundabout-video-norfolk-police

[kalvado]

Van FLIES over roundabout in shocking video - three injured as police launch probe
https://www.express.co.uk/news/uk/1017199/norfolk-news-attleborough-a11-van-roundabout-video-norfolk-police

This is what happens when stupid american drivers try to drive in UK! [ /irony]

[billpa]

Van FLIES over roundabout in shocking video - three injured as police launch probe

He was clearly driving at a safe and proper speed when the roundabout came out of nowhere and attacked him.

Pixel 2

[silverback1065]

Happy national Roundabout week!  best intersection type around! 

[kalvado]

Happy national Roundabout week!  best intersection type around! 

Why do you care? You should be taking a bus, or even better a train - the best transportation mode around!

[tradephoric]

The Pennsylvania Department of Transportation reviewed data for 11 roundabouts on state routes at intersections that were previously stop or signal controlled.  The results looked very good:

-   Fatalities were reduced by 100 percent (from two to zero);
-   Serious injuries were reduced by 100 percent (from seven to zero);
-   Minor injuries were reduced by 95 percent (from 19 to one);
-   Possible/unknown severity injuries were reduced by 92 percent (from 49 to four);
-   Crashes causing only property damage decreased by 2 percent (from 49 to 48); and
-   The total number of crashes dropped 47 percent (from 101 to 54).

PennDOT Data Shows Pennsylvania Roundabouts Reducing Crashes, Injuries and Fatalities
https://www.penndot.gov/pages/all-news-details.aspx?newsid=536[/quote]

The problem with the study is of the 11 roundabouts analyzed, all were simple single-lane roundabouts.  The fact is Pennsylvania hasn't built many multi-lane roundabouts.  I just hope the state doesn't fool themselves into thinking "multi-lane"  roundabouts will see similar crash reductions based on the results of 11 single-lane roundabouts.  The state just recently constructed one of the first multi-lane roundabout in Pennsylvania on State 222 and... surprise, surprise... it's seeing a lot more crashes than they expected.  Of course, the State 222 multi-lane roundabout wasn't included in their study since it just opened this year.  But based on the great results of the "single-lane"  roundabout study, officials have downplayed the increases in crashes on State 222, stating that "accidents will wane as people learn to navigate the new circle" .  I just feel like we have been here before... Pennsylvania should look closely at states like Michigan and Wisconsin if they want to see how large complex multi-lane roundabouts fair.  Here is a statement from PennDOT Secretary Leslie S. Richards:

"Our data shows that modern-day roundabouts reduce crash severity and injuries while improving traffic flow,"

No Leslie, your data shows that single-lane modern-day roundabouts reduce crash severity and injuries while improving traffic flow. It tells us nothing about how multi-lane roundabouts will perform in your state. PennDOT, don't start building complex multi-lane roundabouts willy-nilly based on the results of your little "single-lane" roundabout study. 

[jeffandnicole]

Pennsylvanians only drive in the left lane anyway.  It could be a 10 lane roundabout and they'll all be stacked in the left lane!