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[tradephoric]

There have been at least 6 trucks that have tipped over at Worthington, MN roundabouts since 2015.  Now they are going to refine the curbing to try to prevent these truck tip-overs.  Hopefully whatever they do helps.

Roundabout redesign will improve Worthington's traffic circles
https://www.dglobe.com/business/transportation/4885702-Roundabout-redesign-will-improve-Worthingtons-traffic-circles



August 7, 2015 - Names released in semi roundabout accident
https://www.dglobe.com/news/3813093-names-released-semi-roundabout-accident

October 27, 2017 - These little piggies almost didn't make it to market when a Minn. hog truck rolled
https://www.agweek.com/news/4350581-these-little-piggies-almost-didnt-make-it-market-when-minn-hog-truck-rolled

November 10, 2017 - Tanker hauling cream overturns in Worthington roundabout
https://www.dglobe.com/news/accidents/4356792-tanker-hauling-cream-overturns-worthington-roundabout

July 21, 2018 - A roundabout rollover
https://www.dglobe.com/news/accidents/4475427-roundabout-rollover

August 1, 2018 - Spilled grain in Worthington roundabout
https://www.dglobe.com/news/accidents/4479958-spilled-grain-worthington-roundabout

October 22, 2018 - Roundabout Accident Sends One To Hospital
https://kicdam.com/news/170071-roundabout-accident-sends-one-to-hospital/

[jakeroot]

Maybe if we built these rural roundabouts a bit bigger, we wouldn't even need to use truck aprons.

Exhibit A: this two-lane suburban roundabout in Snohomish County, WA.

[kalvado]

Maybe if we built these rural roundabouts a bit bigger, we wouldn't even need to use truck aprons.

Exhibit A: this two-lane suburban roundabout in Snohomish County, WA.

That requires qualified engineers understanding what they are doing; so nope, not gonna happen.

[DaBigE]

Maybe if we built these rural roundabouts a bit bigger, we wouldn't even need to use truck aprons.

Exhibit A: this two-lane suburban roundabout in Snohomish County, WA.

Bigger comes with a whole new set of problems.

Maybe if we built these rural roundabouts a bit bigger, we wouldn't even need to use truck aprons.

Exhibit A: this two-lane suburban roundabout in Snohomish County, WA.

That requires qualified engineers understanding what they are doing; so nope, not gonna happen.

On top of that, you have software firms that are trying to take the skilled engineer out of the equation. Programs like Torus allow just about anyone with meager CAD skills think they can design a roundabout. Garbage in, garbage out.

[kphoger]

Maybe if we built these rural roundabouts a bit bigger, we wouldn't even need to use truck aprons.

Exhibit A: this two-lane suburban roundabout in Snohomish County, WA.

Bigger comes with a whole new set of problems.

This.

For one thing, years ago, it was commonly stated that larger ICDs encourage drivers to go too fast through the roundabout.

[jakeroot]

Maybe if we built these rural roundabouts a bit bigger, we wouldn't even need to use truck aprons.

Exhibit A: this two-lane suburban roundabout in Snohomish County, WA.

Bigger comes with a whole new set of problems.

This.

For one thing, years ago, it was commonly stated that larger ICDs encourage drivers to go too fast through the roundabout.

Yeah, I know. Speed. Got it. The cause of all of our problems.

But people are going around larger roundabouts at what, maybe 30 mph? Instead of 15 or 20? Increasing the design speed to be closer to the approach limit might then allow you to remove the truck apron, and reduce the chance for tip-over.

I'm not saying our urban or suburban roundabouts need to be designed for 30+ mph circulating speeds, but these rural roundabouts are distant cousins at best. Different traffic; different needs; different environment.

[jeffandnicole]

Maybe if we built these rural roundabouts a bit bigger, we wouldn't even need to use truck aprons.

Exhibit A: this two-lane suburban roundabout in Snohomish County, WA.

That requires qualified engineers understanding what they are doing; so nope, not gonna happen.

Other than there are road markings, not much different than a traditional NJ traffic circle.

The NJ 70/72 circle is a great example.  And of the 5 roadways leading into it, 3 have 55 mph limits; the other 2 have 50 mph limits.

https://maps.app.goo.gl/fKfeKYQC8cHuvu3N9

[DaBigE]

Maybe if we built these rural roundabouts a bit bigger, we wouldn't even need to use truck aprons.

Exhibit A: this two-lane suburban roundabout in Snohomish County, WA.

Bigger comes with a whole new set of problems.

This.

For one thing, years ago, it was commonly stated that larger ICDs encourage drivers to go too fast through the roundabout.

Yeah, I know. Speed. Got it. The cause of all of our problems.

But people are going around larger roundabouts at what, maybe 30 mph? Instead of 15 or 20? Increasing the design speed to be closer to the approach limit might then allow you to remove the truck apron, and reduce the chance for tip-over.

I'm not saying our urban or suburban roundabouts need to be designed for 30+ mph circulating speeds, but these rural roundabouts are distant cousins at best. Different traffic; different needs; different environment.

You're suggesting to nearly double the "design" speed. Faster speeds = greater risk of severe injury, which is supposed to be one of the top selling points for roundabouts.

[kalvado]

Maybe if we built these rural roundabouts a bit bigger, we wouldn't even need to use truck aprons.

Exhibit A: this two-lane suburban roundabout in Snohomish County, WA.

Bigger comes with a whole new set of problems.

This.

For one thing, years ago, it was commonly stated that larger ICDs encourage drivers to go too fast through the roundabout.

Yeah, I know. Speed. Got it. The cause of all of our problems.

But people are going around larger roundabouts at what, maybe 30 mph? Instead of 15 or 20? Increasing the design speed to be closer to the approach limit might then allow you to remove the truck apron, and reduce the chance for tip-over.

I'm not saying our urban or suburban roundabouts need to be designed for 30+ mph circulating speeds, but these rural roundabouts are distant cousins at best. Different traffic; different needs; different environment.

You're suggesting to nearly double the "design" speed. Faster speeds = greater risk of severe injury, which is supposed to be one of the top selling points for roundabouts.

Which only means concept should be reviewed for feasibility as improving safety creates more safety hazards.

[webny99]

I actually think "everything's bigger in America" is the #1 reason roundabouts are less common in the US and don't work as well here as they do in the UK.

We expect big houses, big cars, big roads, big everything, and making some extra turns of your steering wheel, with precision, in the confined space that is a roundabout, runs totally contrary to the way we've developed as a country in the past two centuries.

[DaBigE]

I actually think "everything's bigger in America" is the #1 reason roundabouts are less common in the US and don't work as well here as they do in the UK.

We expect big houses, big cars, big roads, big everything, and making some extra turns of your steering wheel, with precision, in the confined space that is a roundabout, runs totally contrary to the way we've developed as a country in the past two centuries.

I disagree. Roundabouts are designed with the same sized vehicles as any other component of the American highway. The way I see far too many handle basic turns, we've gotten lazy. We fell in love with the traffic light. Most seek the "safety" of being told what to do and when. When human judgement comes into play is when crashes happen. The skill of the American driver has decreased with the addition of new distractions, shorter attention spans (thank you, Twitter), less rigorous drivers ed, and overconfidence in their vehicle's capabilities.

[webny99]

I agree, but I can agree without walking back, clarifying, or altering my original point. So I guess I disagree that there's a disagreement.

[jakeroot]

I'm not saying our urban or suburban roundabouts need to be designed for 30+ mph circulating speeds, but these rural roundabouts are distant cousins at best. Different traffic; different needs; different environment.

You're suggesting to nearly double the "design" speed. Faster speeds = greater risk of severe injury, which is supposed to be one of the top selling points for roundabouts.

Which only means concept should be reviewed for feasibility as improving safety creates more safety hazards.

Right. Maybe the design speed is increased, but speed does not exist in a vacuum. It has to be weighed against other hazards. By increasing the ICD, you can get rid of the truck apron, which may have its own benefits (perhaps outweighing the benefits of tighter circles). Remember that speed alone is not dangerous; it's suddenly coming to a stop that gets you. If roundabouts can be designed for high speed operation, why not? It certainly makes sense along roads with existing high speeds.

My understanding with designing low-speed roundabouts is that the low speeds decrease braking distance and improve reaction time, but both of these things seem to be the result of classic American "everyone sucks so make it as easy as possible" design philosophy. I generally defend this philosophy, but how can we be sure that emergency stops and reaction time concerns aren't symptoms related to the tightness of many of these circles? How do we know that reactionary/emergency movements wouldn't be reduced at roundabouts with larger ICDs? How likely might it be that larger roundabouts would have fewer truck tip-overs? Would larger roundabouts reduce judgement errors? Would we see fewer property-damage collisions (a major issue at roundabouts)?

I'm not asking these questions as though anyone has answers, but I steadfastly refuse to accept any design standards as perfect, especially when there are totally different designs all across the planet for the same situation. As an example, in Germany (p 7), it's accepted that rural roundabouts do not need aprons. The UK also does not seem to use them.

[kalvado]

I actually think "everything's bigger in America" is the #1 reason roundabouts are less common in the US and don't work as well here as they do in the UK.

We expect big houses, big cars, big roads, big everything, and making some extra turns of your steering wheel, with precision, in the confined space that is a roundabout, runs totally contrary to the way we've developed as a country in the past two centuries.

I disagree. Roundabouts are designed with the same sized vehicles as any other component of the American highway. The way I see far too many handle basic turns, we've gotten lazy. We fell in love with the traffic light. Most seek the "safety" of being told what to do and when. When human judgement comes into play is when crashes happen. The skill of the American driver has decreased with the addition of new distractions, shorter attention spans (thank you, Twitter), less rigorous drivers ed, and overconfidence in their vehicle's capabilities.

Thing is, driving is not an art or primary job for most people - it is a necessary evil to get from point A to point B. Don't expect people to practice that for the sake of art.
Moreover, engineering skill is recently lacking in US. Unlike driving, this is the primary job for many involved. And that is what is lacking. I am not sure if this is about too much twitter in design offices or lack of H-1B visas what hurts things....

[Rothman]

I don't see a lack of engineering skill in the U.S.

[jeffandnicole]

Maybe if we built these rural roundabouts a bit bigger, we wouldn't even need to use truck aprons.

Exhibit A: this two-lane suburban roundabout in Snohomish County, WA.

Bigger comes with a whole new set of problems.

This.

For one thing, years ago, it was commonly stated that larger ICDs encourage drivers to go too fast through the roundabout.

Yeah, I know. Speed. Got it. The cause of all of our problems.

But people are going around larger roundabouts at what, maybe 30 mph? Instead of 15 or 20? Increasing the design speed to be closer to the approach limit might then allow you to remove the truck apron, and reduce the chance for tip-over.

I'm not saying our urban or suburban roundabouts need to be designed for 30+ mph circulating speeds, but these rural roundabouts are distant cousins at best. Different traffic; different needs; different environment.

You're suggesting to nearly double the "design" speed. Faster speeds = greater risk of severe injury, which is supposed to be one of the top selling points for roundabouts.

You're thinking of a roundabout design as a one-size-fits-all design.  A roundabout in a rural area with little traffic may be able to obtain faster speeds than one in an urban area.

For the most part, a single lane roundabout's issue wouldn't be the speed of the roundabout, it would be the failure of people yielding prior to entering. 

I don't see a lack of engineering skill in the U.S.

Generally speaking, neither do I.  Most things are built well.  Yes there will be an occasional issue, and it will make a lot of news, and they will be investigated.  Don't expect most engineering issues in a foreign country to make much news in the US.

[DaBigE]

I actually think "everything's bigger in America" is the #1 reason roundabouts are less common in the US and don't work as well here as they do in the UK.

We expect big houses, big cars, big roads, big everything, and making some extra turns of your steering wheel, with precision, in the confined space that is a roundabout, runs totally contrary to the way we've developed as a country in the past two centuries.

I disagree. Roundabouts are designed with the same sized vehicles as any other component of the American highway. The way I see far too many handle basic turns, we've gotten lazy. We fell in love with the traffic light. Most seek the "safety" of being told what to do and when. When human judgement comes into play is when crashes happen. The skill of the American driver has decreased with the addition of new distractions, shorter attention spans (thank you, Twitter), less rigorous drivers ed, and overconfidence in their vehicle's capabilities.

Thing is, driving is not an art or primary job for most people - it is a necessary evil to get from point A to point B. Don't expect people to practice that for the sake of art.
Moreover, engineering skill is recently lacking in US. Unlike driving, this is the primary job for many involved. And that is what is lacking. I am not sure if this is about too much twitter in design offices or lack of H-1B visas what hurts things....

I never said it was an art, but you did hit on why we won't see meaningful crash reductions until we go to autonomous vehicles. Driving has become a necessary, mindless task. Too many drivers are glued to their smartphones when behind the wheel. As for engineering skill, I'll only agree that there is a shortage of skilled labor in the industry.

Maybe if we built these rural roundabouts a bit bigger, we wouldn't even need to use truck aprons.

Exhibit A: this two-lane suburban roundabout in Snohomish County, WA.

Bigger comes with a whole new set of problems.

This.
For one thing, years ago, it was commonly stated that larger ICDs encourage drivers to go too fast through the roundabout.

Yeah, I know. Speed. Got it. The cause of all of our problems.

But people are going around larger roundabouts at what, maybe 30 mph? Instead of 15 or 20? Increasing the design speed to be closer to the approach limit might then allow you to remove the truck apron, and reduce the chance for tip-over.

I'm not saying our urban or suburban roundabouts need to be designed for 30+ mph circulating speeds, but these rural roundabouts are distant cousins at best. Different traffic; different needs; different environment.

You're suggesting to nearly double the "design" speed. Faster speeds = greater risk of severe injury, which is supposed to be one of the top selling points for roundabouts.

You're thinking of a roundabout design as a one-size-fits-all design.  A roundabout in a rural area with little traffic may be able to obtain faster speeds than one in an urban area.

It has nothing to do with urban vs rural. It's a simple fact of physics. More velocity results in more force resulting in more injury. The point of conflict doesn't change just because you're in a rural setting.

[kalvado]

I don't see a lack of engineering skill in the U.S.

Two recent R1 projects - Washington ave ext and  7-787  interchange were rebuilt to original lane layout, if not to original blueprints. Some lane realignment was pretty obvious thing to do.I guess all engineering genius from R1 was absorbed by Exit3 project?

[DaBigE]

I don't see a lack of engineering skill in the U.S.

Two recent R1 projects - Washington ave ext and  7-787  interchange were rebuilt to original lane layout, if not to original blueprints. Some lane realignment was pretty obvious thing to do.I guess all engineering genius from R1 was absorbed by Exit3 project?

You can confirm there was no political and/or financial influence on those decisions? What was the intent of the project pavement rehab or reconstruction? Money may not have been available for the desirable reconstruction.

[Rothman]

I don't see a lack of engineering skill in the U.S.

Two recent R1 projects - Washington ave ext and  7-787  interchange were rebuilt to original lane layout, if not to original blueprints. Some lane realignment was pretty obvious thing to do.I guess all engineering genius from R1 was absorbed by Exit3 project?

I don't see how this shows lack of engineering skill.

[kalvado]

I don't see a lack of engineering skill in the U.S.

Two recent R1 projects - Washington ave ext and  7-787  interchange were rebuilt to original lane layout, if not to original blueprints. Some lane realignment was pretty obvious thing to do.I guess all engineering genius from R1 was absorbed by Exit3 project?

You can confirm there was no political and/or financial influence on those decisions? What was the intent of the project pavement rehab or reconstruction? Money may not have been available for the desirable reconstruction.

those were not minor pavement rehab, those were deep reconstructions. Lane realignment within existing footprint would be pretty straightforward no extra cost task.
In at least one of these projects,  traffic improvement was an objective as NYSDOT even took up an unbearable task of synchronizing traffic lights.  All 3 of them. Apparently, they gave up after realizing this is too much of engineering work to do. 

As for structural engineering.. I can only pray it works better than traffic engineering.
On a grand scheme of things,  professional growth comes with practice. If lane realignment becomes too much of a task to do, then what do you expect in terms of professional growth?

[Rothman]

I don't see a lack of engineering skill in the U.S.

Two recent R1 projects - Washington ave ext and  7-787  interchange were rebuilt to original lane layout, if not to original blueprints. Some lane realignment was pretty obvious thing to do.I guess all engineering genius from R1 was absorbed by Exit3 project?

You can confirm there was no political and/or financial influence on those decisions? What was the intent of the project pavement rehab or reconstruction? Money may not have been available for the desirable reconstruction.

those were not minor pavement rehab, those were deep reconstructions. Lane realignment within existing footprint would be pretty straightforward no extra cost task.
In at least one of these projects,  traffic improvement was an objective as NYSDOT even took up an unbearable task of synchronizing traffic lights.  All 3 of them. Apparently, they gave up after realizing this is too much of engineering work to do. 

As for structural engineering.. I can only pray it works better than traffic engineering.
On a grand scheme of things,  professional growth comes with practice. If lane realignment becomes too much of a task to do, then what do you expect in terms of professional growth?

I still don't know what you're getting at.  Both projects are fine as is.

[kalvado]

I don't see a lack of engineering skill in the U.S.

Two recent R1 projects - Washington ave ext and  7-787  interchange were rebuilt to original lane layout, if not to original blueprints. Some lane realignment was pretty obvious thing to do.I guess all engineering genius from R1 was absorbed by Exit3 project?

You can confirm there was no political and/or financial influence on those decisions? What was the intent of the project pavement rehab or reconstruction? Money may not have been available for the desirable reconstruction.

those were not minor pavement rehab, those were deep reconstructions. Lane realignment within existing footprint would be pretty straightforward no extra cost task.
In at least one of these projects,  traffic improvement was an objective as NYSDOT even took up an unbearable task of synchronizing traffic lights.  All 3 of them. Apparently, they gave up after realizing this is too much of engineering work to do. 

As for structural engineering.. I can only pray it works better than traffic engineering.
On a grand scheme of things,  professional growth comes with practice. If lane realignment becomes too much of a task to do, then what do you expect in terms of professional growth?

I still don't know what you're getting at.  Both projects are fine as is.

They are just so-so, ignoring traffic pattern changes over the decades, failing to use a chance to improve at a minimal cost (if any additional cost at all), and failing to reach some of published objectives - like synchronizing traffic lights.
Yes, it is a passing grade - work was performed using 20+ blueprints. WHo cares?

[Rothman]

I don't see a lack of engineering skill in the U.S.

Two recent R1 projects - Washington ave ext and  7-787  interchange were rebuilt to original lane layout, if not to original blueprints. Some lane realignment was pretty obvious thing to do.I guess all engineering genius from R1 was absorbed by Exit3 project?

You can confirm there was no political and/or financial influence on those decisions? What was the intent of the project pavement rehab or reconstruction? Money may not have been available for the desirable reconstruction.

those were not minor pavement rehab, those were deep reconstructions. Lane realignment within existing footprint would be pretty straightforward no extra cost task.
In at least one of these projects,  traffic improvement was an objective as NYSDOT even took up an unbearable task of synchronizing traffic lights.  All 3 of them. Apparently, they gave up after realizing this is too much of engineering work to do. 

As for structural engineering.. I can only pray it works better than traffic engineering.
On a grand scheme of things,  professional growth comes with practice. If lane realignment becomes too much of a task to do, then what do you expect in terms of professional growth?

I still don't know what you're getting at.  Both projects are fine as is.

They are just so-so, ignoring traffic pattern changes over the decades, failing to use a chance to improve at a minimal cost (if any additional cost at all), and failing to reach some of published objectives - like synchronizing traffic lights.
Yes, it is a passing grade - work was performed using 20+ blueprints. WHo cares?

The only issue I'm aware of along there was the intersection with New Karner and there was no funding to deal with that completely (i.e., the backup turning right onto New Karner from Wash. Ave. Ext. WB).

In terms of traffic signal synchronization, I wonder if that made it into the design approval document.  I imagine fiscal constraints came into play there as well, especially given the large share of local funds put on the project.

[kalvado]

I don't see a lack of engineering skill in the U.S.

Two recent R1 projects - Washington ave ext and  7-787  interchange were rebuilt to original lane layout, if not to original blueprints. Some lane realignment was pretty obvious thing to do.I guess all engineering genius from R1 was absorbed by Exit3 project?

You can confirm there was no political and/or financial influence on those decisions? What was the intent of the project pavement rehab or reconstruction? Money may not have been available for the desirable reconstruction.

those were not minor pavement rehab, those were deep reconstructions. Lane realignment within existing footprint would be pretty straightforward no extra cost task.
In at least one of these projects,  traffic improvement was an objective as NYSDOT even took up an unbearable task of synchronizing traffic lights.  All 3 of them. Apparently, they gave up after realizing this is too much of engineering work to do. 

As for structural engineering.. I can only pray it works better than traffic engineering.
On a grand scheme of things,  professional growth comes with practice. If lane realignment becomes too much of a task to do, then what do you expect in terms of professional growth?

I still don't know what you're getting at.  Both projects are fine as is.

They are just so-so, ignoring traffic pattern changes over the decades, failing to use a chance to improve at a minimal cost (if any additional cost at all), and failing to reach some of published objectives - like synchronizing traffic lights.
Yes, it is a passing grade - work was performed using 20+ blueprints. WHo cares?

The only issue I'm aware of along there was the intersection with New Karner and there was no funding to deal with that completely (i.e., the backup turning right onto New Karner from Wash. Ave. Ext. WB).

In terms of traffic signal synchronization, I wonder if that made it into the design approval document.  I imagine fiscal constraints came into play there as well, especially given the large share of local funds put on the project.

And I saw - with my own eyes - how intersection by wallmart was rebuilt without a slightest though. And I saw multiple iterations of synchronizations attempts along Washington - to the point I was ready to pull over to explain folks what is being done wrong...  That was an epic try, I should say.