Crash prone 'modern roundabouts'

[kalvado]

I don't see the grim irony when someone hits the center of the roundabout at high speed, which would be more indicative of reckless/inattentive driving than a problem with the roundabout itself.  The driver could also have blown through a red light and hit another vehicle, possibly causing additional deaths.

Statistics is, of course, a long lost wizardry....

[tradephoric]

I don't see the grim irony when someone hits the center of the roundabout at high speed, which would be more indicative of reckless/inattentive driving than a problem with the roundabout itself.  The driver could also have blown through a red light and hit another vehicle, possibly causing additional deaths.

Ironic situations according to Alanis Morissette:
A 98 year old man who won the lottery and died the next day...
A death row pardon two minutes too late...
A "No Smoking" sign on your cigarette break...
A ribbon cutting at a roundabout and a fatal crash that same day...

[jakeroot]

I don't see the grim irony when someone hits the center of the roundabout at high speed, which would be more indicative of reckless/inattentive driving than a problem with the roundabout itself.  The driver could also have blown through a red light and hit another vehicle, possibly causing additional deaths.

Could have been a medical emergency too. In either case, why should they pay with their life?

[kalvado]

I don't see the grim irony when someone hits the center of the roundabout at high speed, which would be more indicative of reckless/inattentive driving than a problem with the roundabout itself.  The driver could also have blown through a red light and hit another vehicle, possibly causing additional deaths.

Could have been a medical emergency too. In either case, why should they pay with their life?

Frankly speaking, roundabout isn't the only scenario where loosing control at high speed can be fatal.
The goal of design is to minimize consequences of such mistakes - but individual accident isn't very meaningful without proper statistics.
One can certainly flirt with baessian approach and start making conclusions. But I have to agree with@tradephoric - it's ironic that first fatal crash is logged immediately after safety improvements are completed. Hopefully next one is decades away

[Rothman]

I don't see the grim irony when someone hits the center of the roundabout at high speed, which would be more indicative of reckless/inattentive driving than a problem with the roundabout itself.  The driver could also have blown through a red light and hit another vehicle, possibly causing additional deaths.

Could have been a medical emergency too. In either case, why should they pay with their life?

Medical emergency?  So, they're racing to the hospital?  I still don't see how that's the roundabout's fault.  Ambulance drivers also certainly don't throw all sense out the window when their sirens and lights are on.

Or, if you're saying he had some sort of medical issue while driving, again, if the roundabout wasn't there doesn't mean that he would have survived.

[jakeroot]

Or, if you're saying he had some sort of medical issue while driving, again, if the roundabout wasn't there doesn't mean that he would have survived.

Totally, that's why I'm all for being cautious of obstacles near high-speed roadways, as they can all cause serious injury or death. Like roundabouts.

[kalvado]

Or, if you're saying he had some sort of medical issue while driving, again, if the roundabout wasn't there doesn't mean that he would have survived.

Totally, that's why I'm all for being cautious of obstacles near high-speed roadways, as they can all cause serious injury or death. Like roundabouts.

That's exactly why high speed roads have a lot of engineering features to avoid bad outcomes - such as rumble strips, guardrails, medians, jersey barriers and what not.
Maybe we need to hire an engineer to design roundabouts properly? Looks like none are left on DOTs payroll...

[jeffandnicole]

I don't see the grim irony when someone hits the center of the roundabout at high speed, which would be more indicative of reckless/inattentive driving than a problem with the roundabout itself.  The driver could also have blown through a red light and hit another vehicle, possibly causing additional deaths.

Could have been a medical emergency too. In either case, why should they pay with their life?

Frankly speaking, roundabout isn't the only scenario where loosing control at high speed can be fatal.
The goal of design is to minimize consequences of such mistakes - but individual accident isn't very meaningful without proper statistics.
One can certainly flirt with baessian approach and start making conclusions. But I have to agree with@tradephoric - it's ironic that first fatal crash is logged immediately after safety improvements are completed. Hopefully next one is decades away

Maybe more ironic was per the article, safety improvements had been completed since the summer.  They just held a ribbon cutting ceremony that very day for no other reason than that's what politicians do.

[MASTERNC]

CalTRANS has a video on its new "turbo roundabout".  On one hand, I can see the issue with lane changes in the roundabouts (which I have witnessed personally, whether inadvertent or intentional).  On the other, seems some of these movements require a 90-degree turn across roundabout traffic.

https://www.youtube.com/watch?v=KHYo7Bl_zWg

[kalvado]

CalTRANS has a video on its new "turbo roundabout".  On one hand, I can see the issue with lane changes in the roundabouts (which I have witnessed personally, whether inadvertent or intentional).  On the other, seems some of these movements require a 90-degree turn across roundabout traffic.

https://www.youtube.com/watch?v=KHYo7Bl_zWg

This is a pretty standard 3-lane piece of shitty engineering. And good thing there is no snow so they can have those curbstones in the middle of the road. May sheer off some tires...
They say trucks are accounted for, but I have hard time thinking of a truck turning into an inner lane  with that radius.

[Rothman]

CalTRANS has a video on its new "turbo roundabout".  On one hand, I can see the issue with lane changes in the roundabouts (which I have witnessed personally, whether inadvertent or intentional).  On the other, seems some of these movements require a 90-degree turn across roundabout traffic.

https://www.youtube.com/watch?v=KHYo7Bl_zWg

This is a pretty standard 3-lane piece of shitty engineering. And good thing there is no snow so they can have those curbstones in the middle of the road. May sheer off some tires...
They say trucks are accounted for, but I have hard time thinking of a truck turning into an inner lane  with that radius.

Should have an apron.

[kalvado]

CalTRANS has a video on its new "turbo roundabout".  On one hand, I can see the issue with lane changes in the roundabouts (which I have witnessed personally, whether inadvertent or intentional).  On the other, seems some of these movements require a 90-degree turn across roundabout traffic.

https://www.youtube.com/watch?v=KHYo7Bl_zWg

This is a pretty standard 3-lane piece of shitty engineering. And good thing there is no snow so they can have those curbstones in the middle of the road. May sheer off some tires...
They say trucks are accounted for, but I have hard time thinking of a truck turning into an inner lane  with that radius.

Should have an apron.

There is an apron in the video. But just imagine a heavy 18-wheeler crawling across 3 lanes of traffic and mounting on an apron during the rush hour... Extra points for a tire blown on a curbstone while doing so.

[tradephoric]

Here's an article describing the new turbo roundabout in South Bay that Caltrans built. So after reading through these two paragraphs, did the total number of injury accidents rise or fall once the roundabout was built?

In the weeks following the opening of the roundabout, the intersection saw crashes at more than three times the rate than the year before it was built — jumping from about one accident approximately every eight days to one accident every two and a half days, on average.

None of the crashes since the addition of the roundabout have been fatal or led to serious injury. And while around one in every two accidents led to injury before the turbo roundabout was installed, that number has dropped to one in four, according to a Mercury News analysis.

https://www.mercurynews.com/2024/04/15/first-data-on-south-bays-new-turbo-roundabout-are-in-with-surprising-results-is-it-really-safer/

[tradephoric]

The roundabout at Auburn & Main in Rockford is being converted from a double-lane to a single-lane roundabout.  This is commonly the most crash-prone intersection in Rockford each year.  Post conversion to a single-lane roundabout I doubt it makes the top 10 list.   

Changes Coming To Auburn And Main Streets Roundabout In Effort To Reduce Crashes
https://www.rockrivercurrent.com/2024/05/17/rockford-to-change-auburn-and-main-streets-roundabout-to-reduce-number-of-crashes/

[tradephoric]

Why is this Milwaukee roundabout so difficult for drivers?
https://www.youtube.com/watch?v=PBdcr_u2mN4

[jeffandnicole]

Why is this Milwaukee roundabout so difficult for drivers?
https://www.youtube.com/watch?v=PBdcr_u2mN4

From what I saw, most of the issues are occurring as motorists are coming off the bridge, before the roundabout.

Taking a GSV look at it, there's a single, small roundabout warning sign as motorists approach the bridge.  There's no signage indicating what lane to be in.  As motorists come off the bridge, the visual effect shows a straightaway towards a traffic light and a street lined with buildings.  https://maps.app.goo.gl/pgxCmtrmLzaHKcKU7  Looking at past GSV images, there was chevron signage in place, but they've gone missing. 

So what's wrong with the roundabout?  The lack of signage, especially before the bridge, appears to be a major issue. The sightlines don't help.  Put up something that blocks the view and that would help considerably.  And speed on the approach road going over the bridge probably has a bit to do with it also.

[mrsman]

Why is this Milwaukee roundabout so difficult for drivers?
https://www.youtube.com/watch?v=PBdcr_u2mN4

From what I saw, most of the issues are occurring as motorists are coming off the bridge, before the roundabout.

Taking a GSV look at it, there's a single, small roundabout warning sign as motorists approach the bridge.  There's no signage indicating what lane to be in.  As motorists come off the bridge, the visual effect shows a straightaway towards a traffic light and a street lined with buildings.  https://maps.app.goo.gl/pgxCmtrmLzaHKcKU7  Looking at past GSV images, there was chevron signage in place, but they've gone missing. 

So what's wrong with the roundabout?  The lack of signage, especially before the bridge, appears to be a major issue. The sightlines don't help.  Put up something that blocks the view and that would help considerably.  And speed on the approach road going over the bridge probably has a bit to do with it also.

IMO, this roundabout seems to be more problem than solution.  It seems like there isn't that much traffic coming off the 5th street leg, so that leg can be closed.  (5th street does not operate north of Virginia).  Then we have a T-intersection with Virginia that can be converted back to a signalized intersection.

While this is really a problem of driver error and a lot of speeding, if there are so many significanct accidents occurring here, then there must be a problem of design.  The roundabout needs to go.

[tradephoric]

Phoenix roundabout ranked riskiest intersection in the county
https://www.youtube.com/watch?v=tGw2Kr20nbs

Maricopa county is going to circle back and study the roundabout that was built in 2002. From 2017-2021 there were 411 crashes at the 99th Avenue and Lower Buckeye Road roundabout. 

[tradephoric]

From 44 crashes a year before the roundabout to hundreds of crashes after.  The government in Lake Stevens Washington spent 70 million dollars building a set of roundabouts and made a problem 4X worse (when looking at total crashes).

[LilianaUwU]

Why do you have such a grudge against roundabouts? Did your hometown get an undeserving roundabout like mine did?

[NE2]

Are we still at this?

[jakeroot]

From 44 crashes a year before the roundabout to hundreds of crashes after.  The government in Lake Stevens Washington spent 70 million dollars building a set of roundabouts and made a problem 4X worse (when looking at total crashes).

The particularly irritating part of this whole area is that it was meant to be an underpass, but the plans were scrapped when it became apparent that the water table below the road was too high to allow for an underpass.

It should be remembered that WSDOT refused to raise the speed limits from 70 to 75 because it was predicted there would be 1.5-ish more deaths on the road per-year. Meanwhile, overall crashes are completely meaningless as long as no one is seriously injured. Which hey, fair enough, but can we not find a middle ground?

[epzik8]

From 44 crashes a year before the roundabout to hundreds of crashes after.  The government in Lake Stevens Washington spent 70 million dollars building a set of roundabouts and made a problem 4X worse (when looking at total crashes).

Christ, Washington and Maryland are like night and day with roundabouts. We've had them longer than almost any other U.S. state, and people here have them down to a T.

[jakeroot]

Why do you have such a grudge against roundabouts? Did your hometown get an undeserving roundabout like mine did?

I don't have any particular grudge towards multi-lane roundabouts, but you can't honestly deny that multi-lane roundabouts do have a lot more crashes than single-lane roundabouts.

tradephoric might have cherry-picked data over the last ten years, but I've yet to see anyone refute his data. In fact, based on how often multi-lane roundabouts have lane reductions, it seems clear to me that these large roundabouts are, in fact, very crash-prone. Even if people aren't dying and overall traffic congestion is reduced.

[LilianaUwU]

Why do you have such a grudge against roundabouts? Did your hometown get an undeserving roundabout like mine did?

I don't have any particular grudge towards multi-lane roundabouts, but you can't honestly deny that multi-lane roundabouts do have a lot more crashes than single-lane roundabouts.

Can't disagree, and it's not wrong since it's backed up with stats, but this is a 117-page thread about the same thing. I think I get it after 5 pages.