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Author Topic: Crash prone 'modern roundabouts'  (Read 294317 times)

kalvado

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Re: Crash prone 'modern roundabouts'
« Reply #2225 on: August 22, 2019, 08:52:24 PM »

Using turn signals properly in a roundabout will help immensely.  Of course, some parts of the country have an even bigger problem with signalling!
you mean turning on emergency flashes to indicate left and right turn at the same time?
Any signal would be good, for most of the morons seen on the road.
Don't look into the mirror while driving, look out!
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tradephoric

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Re: Crash prone 'modern roundabouts'
« Reply #2226 on: August 22, 2019, 11:34:03 PM »

Modifications, including blinky signs, have been made to Hilliard's Main Street and Cemetery Road roundabout.

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tradephoric

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Re: Crash prone 'modern roundabouts'
« Reply #2227 on: August 23, 2019, 11:02:08 AM »

A new roundabout is being proposed at Orchard Lake Road and Ludden St in Oakland County, Michigan just south of the accident-prone roundabout at Orchard Lake & 14 Mile (which saw 144 crashes including 20 injury crashes in 2018 alone).  One of the cited problems in the article is that there are a lot of accidents caused by people turning left out of the driveways just south of the roundabout.  Now they plan to convert Orchard Lake to a divided boulevard and force drivers to turn right out of the driveways and use the new proposed roundabout to make their U-turn.

New roundabout, boulevard planned for Orchard Lake Road in Farmington Hills
https://www.hometownlife.com/story/news/local/farmington-hills/2019/08/22/another-roundabout-planned-orchard-lake-road-farmington-hills/2083910001/


In the news report, I just noticed they recently added some massive boulders in the central island of the 14 Mile & Orchard Lake roundabout.  A lot of deaths that occur at roundabouts are associated with single-car fixed object accidents and a boulder is a pretty big-ass fixed object… apparently 144 crashes and 20 injury crashes just isn’t enough of a problem already.
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thspfc

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Re: Crash prone 'modern roundabouts'
« Reply #2228 on: August 23, 2019, 08:54:39 PM »

Not sure what the thought process is for MDOT on that one.
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jakeroot

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Re: Crash prone 'modern roundabouts'
« Reply #2229 on: August 31, 2019, 01:17:39 AM »

I saw this aerial image of a new roundabout constructed in Spokane, WA, as part of a Costco development (original PDF here). What caught my eye was the median extensions visible on the bottom and right approaches (eastern and northern respectively), which are made of asphalt, plus the central island which was clearly extended after construction (notice the odd curving lines). It was clearly meant to incorporate additional circulating lanes; namely, a second eastern approach lane, and a third northern approach lane. While it was not constructed with such things, it clearly is meant to be modified as necessary for those things later on. If that third lane were built as (perhaps) originally planned, it would be the only roundabout in Washington with three circulating lanes.

There's no saying why it wasn't built this way to begin with, but I think WSDOT has had some issues with some of their larger roundabouts, in terms of crashes, so they might be trying to play more conservatively now than before.

(Google Maps location)



Here's some aerial video as well:

« Last Edit: August 31, 2019, 01:58:38 AM by jakeroot »
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motorola870

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Re: Crash prone 'modern roundabouts'
« Reply #2230 on: August 31, 2019, 07:25:22 AM »

I saw this aerial image of a new roundabout constructed in Spokane, WA, as part of a Costco development (original PDF here). What caught my eye was the median extensions visible on the bottom and right approaches (eastern and northern respectively), which are made of asphalt, plus the central island which was clearly extended after construction (notice the odd curving lines). It was clearly meant to incorporate additional circulating lanes; namely, a second eastern approach lane, and a third northern approach lane. While it was not constructed with such things, it clearly is meant to be modified as necessary for those things later on. If that third lane were built as (perhaps) originally planned, it would be the only roundabout in Washington with three circulating lanes.

There's no saying why it wasn't built this way to begin with, but I think WSDOT has had some issues with some of their larger roundabouts, in terms of crashes, so they might be trying to play more conservatively now than before.

(Google Maps location)



Here's some aerial video as well:

If someone is going to design such a mess of a roundabout is it really saving over a standard traffic signal? this looks like someone wanted to get creative and waste tax payer money. This has way too much right of way wasted. As much ROW they used this intersection could be been completely grade seperated! This is a case of pork spending and not being reasonable. I am in area where traffic circles are becoming more common but they will not place them on major roads. They are used in roads adjoining new shopping areas or residential areas where it makes more sense to do a circle than putting in a full fledged signal. If it were my decision if they actually think they needed that much right of way it would have just been smarter to make a 4 lane overpass and make service ramps to the Costco. Like is the Costco going to go anywhere? This roundabout is eventually likely to be signalized anyways.
« Last Edit: August 31, 2019, 07:39:45 AM by motorola870 »
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jeffandnicole

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Re: Crash prone 'modern roundabouts'
« Reply #2231 on: August 31, 2019, 07:36:28 AM »

If someone is going to design such a mess of a roundabout is it really saving over a standard traffic signal? this looks like someone wanted to get creative and waste tax payer money. This has way too much right of way wasted. As much ROW they used this intersection could be been completely grade seperated! This is a case of pork spending and not being reasonable.

It's not always about the money.  If so, we wouldn't even have interchanges or traffic lights to begin with.  As in most cases the cheapest option is the do nothing option, with the second option being a standard intersection with stop signs, they were willing to spend money.  Ultimately it comes down to what they believe will bring the most bang for the buck.

Also, if this is right outside a new shopping center, the developer may have paid to install the roundabout, which then IS the cheapest option long-term, because the town/city/county/state won't have to pay the electric for a traffic light in the future.
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motorola870

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Re: Crash prone 'modern roundabouts'
« Reply #2232 on: August 31, 2019, 07:42:41 AM »

If someone is going to design such a mess of a roundabout is it really saving over a standard traffic signal? this looks like someone wanted to get creative and waste tax payer money. This has way too much right of way wasted. As much ROW they used this intersection could be been completely grade seperated! This is a case of pork spending and not being reasonable.

It's not always about the money.  If so, we wouldn't even have interchanges or traffic lights to begin with.  As in most cases the cheapest option is the do nothing option, with the second option being a standard intersection with stop signs, they were willing to spend money.  Ultimately it comes down to what they believe will bring the most bang for the buck.

Also, if this is right outside a new shopping center, the developer may have paid to install the roundabout, which then IS the cheapest option long-term, because the town/city/county/state won't have to pay the electric for a traffic light in the future.
The footprint of the circle is not reasonable. It is mind blowing they actually thought a 3 lane inner circle would solve issues.
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DaBigE

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Re: Crash prone 'modern roundabouts'
« Reply #2233 on: August 31, 2019, 10:36:05 AM »

If someone is going to design such a mess of a roundabout is it really saving over a standard traffic signal? this looks like someone wanted to get creative and waste tax payer money. This has way too much right of way wasted. As much ROW they used this intersection could be been completely grade seperated! This is a case of pork spending and not being reasonable.

It's not always about the money.  If so, we wouldn't even have interchanges or traffic lights to begin with.  As in most cases the cheapest option is the do nothing option, with the second option being a standard intersection with stop signs, they were willing to spend money.  Ultimately it comes down to what they believe will bring the most bang for the buck.

Also, if this is right outside a new shopping center, the developer may have paid to install the roundabout, which then IS the cheapest option long-term, because the town/city/county/state won't have to pay the electric for a traffic light in the future.
The footprint of the circle is not reasonable. It is mind blowing they actually thought a 3 lane inner circle would solve issues.

With the amount of traffic that roundabout was designed to handle, a signalized option wouldn't be much smaller. Look at the impacts of an adjacent intersection.
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jakeroot

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Re: Crash prone 'modern roundabouts'
« Reply #2234 on: August 31, 2019, 02:21:29 PM »

I don't think roundabouts really are too much larger than some regular signalized intersections, especially when you take into account the fewer number of required "turn only" lanes. Where they "getcha" is with the slip lanes. At the "node", roundabouts are almost always larger (their primary advantage being narrower approach roads); when they start adding in slip lanes for right turns, the width of the "node" does get quite wide, quite quickly.

The chicanes on the approach, which are certainly wise given the 55-mph limit on Newport Highway, could have probably dipped left towards the oncoming lanes, and then curved right into the roundabout, instead of right, then left, and then right again into the roundabout. That could have saved on some ROW too. If they removed the slip lanes, that could have helped too. Fewer crosswalks that way too.

Also, if this is right outside a new shopping center, the developer may have paid to install the roundabout, which then IS the cheapest option long-term, because the town/city/county/state won't have to pay the electric for a traffic light in the future.

It was indeed funded by the developer. There's another roundabout just to the east that currently serves no purpose, except to incorporate more legs for other development later on.
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6a

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Re: Crash prone 'modern roundabouts'
« Reply #2235 on: August 31, 2019, 04:07:55 PM »

Modifications, including blinky signs, have been made to Hilliard's Main Street and Cemetery Road roundabout.


Yeah, they also put in speed bumps at the crosswalks. I always forget they’re there since there’s no warning whatsoever about their existence. Overall I’d say they did a decent job. The southern leg of the Scioto Darby one lost a lane, so eastbound traffic now has a dedicated right only lane.
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jamess

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Re: Crash prone 'modern roundabouts'
« Reply #2236 on: September 04, 2019, 11:56:28 AM »

Recently drove through NJ and passed what appeared to be a brand new roundabout, but they still had the circle lanes yield to entering traffic. Come on!

This bad boy:

https://goo.gl/maps/ePJh6ZJoR4dBQKh17

« Last Edit: September 04, 2019, 11:58:33 AM by jamess »
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tradephoric

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Re: Crash prone 'modern roundabouts'
« Reply #2237 on: September 04, 2019, 12:52:01 PM »

^That's actually an old traffic circle but was reconfigured recently to include slip lanes and truck aprons.  Looks like yield operation is the same to the old circle with traffic inside the circle yielding to traffic entering the circle.  That is definitely a traffic circle and not a modern roundabout. 
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jakeroot

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Re: Crash prone 'modern roundabouts'
« Reply #2238 on: September 04, 2019, 01:06:39 PM »

^^
It's not a modern roundabout, but you have to give credit to New Jersey for excellence striping and markings. Compared to the old layout, this should produce far fewer accidents.

Of course, I don't have any idea what kind of accidents the intersection was experiencing before. But a lot of those old circles had almost no markings, and drivers just sort of flying all over the place. I assume this would be a little better**

**despite this, I do support the idea of regular roundabouts not having markings. I've never been convinced that they are necessary at traditional modern roundabouts. But with an intersection the size of what we see above, it might be necessary.
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jeffandnicole

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Re: Crash prone 'modern roundabouts'
« Reply #2239 on: September 04, 2019, 01:12:47 PM »

Recently drove through NJ and passed what appeared to be a brand new roundabout, but they still had the circle lanes yield to entering traffic. Come on!

This bad boy:

https://goo.gl/maps/ePJh6ZJoR4dBQKh17



NJ has done this to a few traffic circles.  They incorporate many roundabout features but they stop short of calling it a roundabout.  Using the Brooklawn Circle for example, they go so far as to sign it as a traffic circle: https://goo.gl/maps/UpdFGGysnbbYS83T8 .

In response to Jackroot...I think the lane markings do help control traffic a bit more, and I imagine it does cut down on some sideswipe accidents.
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jamess

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Re: Crash prone 'modern roundabouts'
« Reply #2240 on: September 05, 2019, 10:11:47 AM »

Recently drove through NJ and passed what appeared to be a brand new roundabout, but they still had the circle lanes yield to entering traffic. Come on!

This bad boy:

https://goo.gl/maps/ePJh6ZJoR4dBQKh17



NJ has done this to a few traffic circles.  They incorporate many roundabout features but they stop short of calling it a roundabout.  Using the Brooklawn Circle for example, they go so far as to sign it as a traffic circle: https://goo.gl/maps/UpdFGGysnbbYS83T8 .

In response to Jackroot...I think the lane markings do help control traffic a bit more, and I imagine it does cut down on some sideswipe accidents.

Oddly, the circle across the tracks has no indication as to who yields in this spot:

https://goo.gl/maps/P9Lxsw3hHVnfAqMd6
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jeffandnicole

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Re: Crash prone 'modern roundabouts'
« Reply #2241 on: September 05, 2019, 10:31:26 AM »

Recently drove through NJ and passed what appeared to be a brand new roundabout, but they still had the circle lanes yield to entering traffic. Come on!

This bad boy:

https://goo.gl/maps/ePJh6ZJoR4dBQKh17



NJ has done this to a few traffic circles.  They incorporate many roundabout features but they stop short of calling it a roundabout.  Using the Brooklawn Circle for example, they go so far as to sign it as a traffic circle: https://goo.gl/maps/UpdFGGysnbbYS83T8 .

In response to Jackroot...I think the lane markings do help control traffic a bit more, and I imagine it does cut down on some sideswipe accidents.

Oddly, the circle across the tracks has no indication as to who yields in this spot:

https://goo.gl/maps/P9Lxsw3hHVnfAqMd6

Correct - that's a traditional NJ Traffic Circle.  Most didn't have any traffic control whatsoever.  If you were to continue around the circle, the next merge point has no signage either.  However, the 3rd leg on this circle does - traffic entering the circle yields to those already in the circle.  https://goo.gl/maps/KocSdGEAHqkqqwoS6

The next question...why was this circle not modified the same time the other circle, just on the other side of the overpass, was modified?  I do know that in a future project that will replace the overpass over a river just before your link, they are going to see if they address the severe flooding that occurs here quite often; possibly with some sort of seawall. At that time, maybe they'll modernize this circle, Jersey style!
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tradephoric

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Re: Crash prone 'modern roundabouts'
« Reply #2242 on: September 20, 2019, 05:53:09 PM »

An elderly couple was killed after their Toyota Prius crashed into the concrete roundabout at Highway 12 and 113 near Suisun City, California.  Retaining walls in the the central islands of roundabouts... specifically roundabouts in rural/suburban locations... doesn't seem necessary.



Crash at Highways 12/113 roundabout leaves 2 dead
https://www.dailyrepublic.com/all-dr-news/solano-news/suisun-city/crash-at-highways-12-113-roundabout-leaves-2-dead/comment-page-1/


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jakeroot

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Re: Crash prone 'modern roundabouts'
« Reply #2243 on: September 20, 2019, 10:56:25 PM »

An elderly couple was killed after their Toyota Prius crashed into the concrete roundabout at Highway 12 and 113 near Suisun City, California.  Retaining walls in the the central islands of roundabouts... specifically roundabouts in rural/suburban locations... doesn't seem necessary.

Hell of a start. Decorations should not kill people.
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Brian556

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Re: Crash prone 'modern roundabouts'
« Reply #2244 on: September 21, 2019, 12:24:16 AM »

An elderly couple was killed after their Toyota Prius crashed into the concrete roundabout at Highway 12 and 113 near Suisun City, California.  Retaining walls in the the central islands of roundabouts... specifically roundabouts in rural/suburban locations... doesn't seem necessary.

Hell of a start. Decorations should not kill people.

Decorations don't kill people. Dumb drivers kill themselves
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jakeroot

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Re: Crash prone 'modern roundabouts'
« Reply #2245 on: September 21, 2019, 02:03:02 AM »

An elderly couple was killed after their Toyota Prius crashed into the concrete roundabout at Highway 12 and 113 near Suisun City, California.  Retaining walls in the the central islands of roundabouts... specifically roundabouts in rural/suburban locations... doesn't seem necessary.

Hell of a start. Decorations should not kill people.

Decorations don't kill people. Dumb drivers kill themselves

Who's to say there wasn't a medical emergency? Fact is they'd still be alive if they didn't whack into that concrete median. Maybe another car could have killed them, but they didn't get far enough to find out.
« Last Edit: September 21, 2019, 02:05:20 AM by jakeroot »
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jeffandnicole

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Re: Crash prone 'modern roundabouts'
« Reply #2246 on: September 21, 2019, 06:07:43 AM »

An elderly couple was killed after their Toyota Prius crashed into the concrete roundabout at Highway 12 and 113 near Suisun City, California.  Retaining walls in the the central islands of roundabouts... specifically roundabouts in rural/suburban locations... doesn't seem necessary.

Hell of a start. Decorations should not kill people.

Decorations don't kill people. Dumb drivers kill themselves

Who's to say there wasn't a medical emergency? Fact is they'd still be alive if they didn't whack into that concrete median. Maybe another car could have killed them, but they didn't get far enough to find out.
An elderly couple was killed after their Toyota Prius crashed into the concrete roundabout at Highway 12 and 113 near Suisun City, California.  Retaining walls in the the central islands of roundabouts... specifically roundabouts in rural/suburban locations... doesn't seem necessary.

Hell of a start. Decorations should not kill people.

Decorations don't kill people. Dumb drivers kill themselves

Who's to say there wasn't a medical emergency? Fact is they'd still be alive if they didn't whack into that concrete median. Maybe another car could have killed them, but they didn't get far enough to find out.

Or maybe they would've killed innocent people in that other car.
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DaBigE

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Re: Crash prone 'modern roundabouts'
« Reply #2247 on: September 21, 2019, 04:55:09 PM »

An elderly couple was killed after their Toyota Prius crashed into the concrete roundabout at Highway 12 and 113 near Suisun City, California.  Retaining walls in the the central islands of roundabouts... specifically roundabouts in rural/suburban locations... doesn't seem necessary.

Hell of a start. Decorations should not kill people.

Decorations don't kill people. Dumb drivers kill themselves

Who's to say there wasn't a medical emergency? Fact is they'd still be alive if they didn't whack into that concrete median. Maybe another car could have killed them, but they didn't get far enough to find out.

What if they kept driving straight from the base approach of a T-intersection and ran into a building or the concrete stairs leading up to a building. Would you blame the building?
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jakeroot

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Re: Crash prone 'modern roundabouts'
« Reply #2248 on: September 21, 2019, 05:28:53 PM »

Or maybe they would've killed innocent people in that other car.

Still didn't get to find out. Wouldn't you rather take a chance than just kill anyone who loses control?

What if they kept driving straight from the base approach of a T-intersection and ran into a building or the concrete stairs leading up to a building. Would you blame the building?

Buildings serve a purpose...fucking concrete central islands do what exactly? Kill people who lose control?
« Last Edit: September 21, 2019, 07:11:17 PM by jakeroot »
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DaBigE

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Re: Crash prone 'modern roundabouts'
« Reply #2249 on: September 21, 2019, 11:47:05 PM »

Or maybe they would've killed innocent people in that other car.

Still didn't get to find out. Wouldn't you rather take a chance than just kill anyone who loses control?

I'm not trying to defend the placement of the concrete, but in order for it to kill someone, it isn't just losing control. Excessive speed plays a significant role. Look at the photo... there's plenty of warning. For crying out loud, there's two sets of overhead flashing lights. Even if the concrete wasn't there, a basic mounded central island might not have changed the ultimate outcome. Depending on speed (which we still don't know), they could have been sent flying.

Given the age of the occupants, there's no guarantee they would have survived hitting a breakaway street light. With age comes added frailty. Until the full report comes out, it could have been a medical condition before they ever hit anything. It could have been a heart attack when they crashed. Until we know the medical report and the speed they were traveling at saying the concrete killed them is only one hypothesis. Is placing vertical concrete in that location advisable? No. But it's not like the concrete randomly decided to spring up and yell "boo!"

What if they kept driving straight from the base approach of a T-intersection and ran into a building or the concrete stairs leading up to a building. Would you blame the building?
Buildings serve a purpose...fucking concrete central islands do what exactly? Kill people who lose control?

Ok, don't like that scenario, how about a power pole on the outside of a curve. Or, a big 80-year old oak tree. Either of those items don't come with as much warning. When does it become the driver's fault?
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