Crash prone 'modern roundabouts'

[kphoger]

As much as we love to say that life is "invaluable", there is a number to use - and it's not very high. Same with injuries, more granular data on injuries would be interesting to flatten into financial value.  Same with extent of car damage.

And, see, I've been assuming that, when a department is tasked with "fixing an intersection", the reason is primarily to reduce the number of deaths and serious injuries that are occurring there.  So, if they do that, then I figure it's a success—even if other types of crashes go up.  That is to say...

— Too many traffic fatalities are occurring here.  Fix that.
— There.  Fixed.  Installed a roundabout.  Fatalities have gone down.
— But non-fatal accidents have gone up.
— That's what they told us to fix.

[kphoger]

Last, but not the least for me personally... I do have to cross the road near roundabout these days (thanks to certain people messing with parking arrangements, but whatever). And it IS tough. I am paying attention, I do make eye contacts, I can move fast. But it's just a high risk exercise.

This is a great point kalvado makes.  Looking at the safety within 250 feet of an intersection (whether it be a traffic signal or a roundabout) is great, but how does the intersection impact safety a 1/4 mile down the road for a driver trying to pull out of their unsignalized sub street? There are several traffic signals in the county i live that cycle 24/7 to create gaps in traffic to allow drivers to more easily exit nearby sub streets. A free-flowing roundabout corridor could potentially lead to more injury accidents mid-block.

First of all, that sounds awfully hypothetical—which is surprising to hear from you, who are usually interested in actual statistics.  I'd love to see an actual study of this sort but, failing that, let's just leave it as pure imagination.

Secondly, I agree that free-flowing traffic exiting a roundabout makes it more difficult for cross-traffic nearby.  You mentioned vehicular traffic coming out from a side-street, but I was thinking even more about pedestrian traffic trying to cross at a point mid-block nearby—especially those not crossing at a marked (and actually yielded to by drivers) crosswalk.

[tradephoric]

First of all, that sounds awfully hypothetical—which is surprising to hear from you, who are usually interested in actual statistics.  I'd love to see an actual study of this sort but, failing that, let's just leave it as pure imagination.

I agree.  I have had the thought that roundabouts may lead to more accidents downstream due to the free-flowing nature of roundabouts leading to fewer gaps in traffic, but i haven't dwelled on it seeing that it is so difficult to quantify.  A study that attempts to look at the impact would probably have some pretty big holes in it.

[kalvado]

As much as we love to say that life is "invaluable", there is a number to use - and it's not very high. Same with injuries, more granular data on injuries would be interesting to flatten into financial value.  Same with extent of car damage.

And, see, I've been assuming that, when a department is tasked with "fixing an intersection", the reason is primarily to reduce the number of deaths and serious injuries that are occurring there.  So, if they do that, then I figure it's a success—even if other types of crashes go up.  That is to say...

— Too many traffic fatalities are occurring here.  Fix that.
— There.  Fixed.  Installed a roundabout.  Fatalities have gone down.
— But non-fatal accidents have gone up.
— That's what they told us to fix.

Are there a lot of intersections in roundabout throughput range where fatal accidents are more or less regular events, not one-off-in-decade?

[tradephoric]

The US95 and US-50 roundabout in Lyon County, Nevada has been the site of 3 fatal crashes since opening in May 2020.  It's been averaging 0.6 fatal crashes per year since opening.

Silver Springs man identified in fatal crash on US-50 in Lyon County
https://www.carsonnow.org/05/29/2024/silver-springs-man-identified-fatal-crash-us-50-lyon-county

Fallon Man Dies in Crash Near U.S. 50 Roundabout in Silver Springs
https://www.2news.com/fallon-man-dies-in-crash-near-u-s-50-roundabout-in-silver-springs/article_5bcf26bc-a38c-598c-beed-40bde873699b.html

NHP: Mechanical failure to blame for fiery Silver Springs crash
https://www.kolotv.com/2021/05/29/fiery-silver-springs-crash-was-fatal/

The question is how many fatal crashes per year does the deadliest intersection in all of America average?  Is it higher or lower than 0.60 fatal crashes per year?

[kalvado]

The US95 and US-50 roundabout in Lyon County, Nevada has been the site of 3 fatal crashes since opening in May 2020.  It's been averaging 0.6 fatal crashes per year since opening.

Silver Springs man identified in fatal crash on US-50 in Lyon County
https://www.carsonnow.org/05/29/2024/silver-springs-man-identified-fatal-crash-us-50-lyon-county

Fallon Man Dies in Crash Near U.S. 50 Roundabout in Silver Springs
https://www.2news.com/fallon-man-dies-in-crash-near-u-s-50-roundabout-in-silver-springs/article_5bcf26bc-a38c-598c-beed-40bde873699b.html

NHP: Mechanical failure to blame for fiery Silver Springs crash
https://www.kolotv.com/2021/05/29/fiery-silver-springs-crash-was-fatal/

The question is how many fatal crashes per year does the deadliest intersection in all of America average?  Is it higher or lower than 0.60 fatal crashes per year?

Purely statistically, if you have a pretty busy intersection with 50k/day traffic, 6 drivers are going to die that year in crashes. If we're talking about in-and-out commute where people pass same intersection twice a day, it's 25k people and 3 fatalities per year.
That doesn't mean all 3 are in the intersection, that is over 12k miles average US driver goes a year.
So 0.6 is really a very high number, meaning just commute through 5 such intersections totally exhausts fatality statistics.   

[kphoger]

I'm having a hard time finding data for fatal accidents in Wichita, but the stoplight at 21st & Woodlawn, which had the fourth-highest number of accidents in 2023 (but the top one that's not along Kellogg) had 36 total crashes that year.  Kellogg & Rock gets about 100 crashes per year.  I wish I could narrow these down by fatalities, though.

[tradephoric]

According to the NHTSA Fatality Analysis Reporting System, there were 15 intersections in the United States with 7 or more fatal crashes between 2000 and 2019.  The most dangerous intersection was Lalor Street & SR-129 in Mercer County New Jersey with 9 fatal crashes.  That comes out to 0.45 fatal crashes per year (9 fatal crashes/20 years of data) which is lower than the 0.6 fatal crashes per year at the US95 and US-50 roundabout in Lyon County, Nevada (3 fatal crashes/5 years of data). 

Five years of data seems adequate to start comparing fatal crash rates, and it's pretty wild that an argument can be made that the US95 and US-50 roundabout is the deadliest intersection in America (based on fatal crashes/year) especially since roundabouts are suppose to reduce fatal crashes by 90% according to the FHWA.


https://www.fanglawfirm.com/the-deadliest-intersections-in-the-united-states/

[Scott5114]

it's pretty wild that an argument can be made that the US95 and US-50 roundabout is the deadliest intersection in America

It's pretty wild because it's not a very good argument. Silver Springs is not even the most dangerous intersection in Nevada (NV-160 at El Capitan Way has double the number of fatalities).

Also US-95 and US-50 intersect in Fallon, not in Silver Springs, and there is no roundabout in Fallon.

[tradephoric]

It's pretty wild because it's not a very good argument. Silver Springs is not even the most dangerous intersection in Nevada (NV-160 at El Capitan Way has double the number of fatalities).

Source please.

Also US-95 and US-50 intersect in Fallon, not in Silver Springs, and there is no roundabout in Fallon.

There is a US-95 (in Fallon) and a US-95ALT (in Silver Srpings).  Admittedly i kept saying US-95 so i can see where the confusion came from.  Here are the exact coordinates of the deadly Nevada roundabout: 39.4162024,-119.2249773

[Scott5114]

Source please.

It says so in your source (if you scroll down there's a table with the deadliest intersection in each state).

[tradephoric]

It says so in your source (if you scroll down there's a table with the deadliest intersection in each state).

While the NV-160 at El Cappitan intersection may have been the deadliest intersection in Nevada at one point, it's no longer the case.  A traffic signal was installed at the intersection in 2016 and the number of fatalities have dropped.  Here's an aerial of the intersection from 2012.  I wouldn't want to cross that roadway without a traffic signal... it looks like a death trap.

[Scott5114]

I wouldn't want to cross that roadway without a traffic signal... it looks like a death trap.

Heh, the arterial I turn onto from my neighborhood looks exactly like Blue Diamond did then. It has never seemed particularly unsafe...but then my arterial doesn't carry anywhere near the amount of traffic that Blue Diamond does.

Physical road geometry is just one part of the equation.

[tradephoric]

Besides the US-95alt and US-50 roundabout in Silver Springs, are there any intersections in Nevada that have had 3 fatal crashes over the past 5 years?

[tradephoric]

The following website lists the 50 most dangerous intersections in Nevada between 2019 and 2023. There are 4 intersections on the list with 2 fatalities but none had 3. 

https://valientemott.com/firm-news/nevadas-most-dangerous-intersections/

A convincing case can be made that the US-95alt and US-50 roundabout in Silver Springs is the deadliest intersection in Nevada right now.  Here are news reports of the 3 fatal crashes at the roundabout since opening in 2020:

Silver Springs man identified in fatal crash on US-50 in Lyon County
https://www.carsonnow.org/05/29/2024/silver-springs-man-identified-fatal-crash-us-50-lyon-county

Fallon Man Dies in Crash Near U.S. 50 Roundabout in Silver Springs
https://www.2news.com/fallon-man-dies-in-crash-near-u-s-50-roundabout-in-silver-springs/article_5bcf26bc-a38c-598c-beed-40bde873699b.html

NHP: Mechanical failure to blame for fiery Silver Springs crash
https://www.kolotv.com/2021/05/29/fiery-silver-springs-crash-was-fatal/

[kphoger]

Silver Springs man identified in fatal crash on US-50 in Lyon County
https://www.carsonnow.org/05/29/2024/silver-springs-man-identified-fatal-crash-us-50-lyon-county

Traveling too fast for conditions, struck decorative rocks in central island.

Fallon Man Dies in Crash Near U.S. 50 Roundabout in Silver Springs
https://www.2news.com/fallon-man-dies-in-crash-near-u-s-50-roundabout-in-silver-springs/article_5bcf26bc-a38c-598c-beed-40bde873699b.html

Didn't slow down, hit decorative rocks in central island, and flipped.

NHP: Mechanical failure to blame for fiery Silver Springs crash
https://www.kolotv.com/2021/05/29/fiery-silver-springs-crash-was-fatal/

Truck's brakes failed, pushed vehicle into decorative rocks in central island, and caught fire.


Anyone else notice a common theme here?

[kalvado]

Silver Springs man identified in fatal crash on US-50 in Lyon County
https://www.carsonnow.org/05/29/2024/silver-springs-man-identified-fatal-crash-us-50-lyon-county

Traveling too fast for conditions, struck decorative rocks in central island.

Fallon Man Dies in Crash Near U.S. 50 Roundabout in Silver Springs
https://www.2news.com/fallon-man-dies-in-crash-near-u-s-50-roundabout-in-silver-springs/article_5bcf26bc-a38c-598c-beed-40bde873699b.html

Didn't slow down, hit decorative rocks in central island, and flipped.

NHP: Mechanical failure to blame for fiery Silver Springs crash
https://www.kolotv.com/2021/05/29/fiery-silver-springs-crash-was-fatal/

Truck's brakes failed, pushed vehicle into decorative rocks in central island, and caught fire.


Anyone else notice a common theme here?

Yes, a poorly designed intersection.

[Scott5114]

So what intersection design would have prevented these "driving too fast for conditions" collisions? It's not a signal-controlled intersection, because the same thing happens at those but worse.

I'd be interested in seeing what the crash history for Silver Springs looks like before the roundabout went in. Given the combination of "rural Nevada", "busy intersection at the transition from populated to unpopulated", and "at the bottom of a grade", I would expect it to be the same or higher.

Remember, in Nevada it is not unusual for rural drivers to straddle the centerline so they can exceed 100 mph more easily. Nobody finds anything wrong with this behavior because they're not around to see it. (And I bet if your daily drive involved US 50 you'd do it too.)

[kalvado]

So what intersection design would have prevented these "driving too fast for conditions" collisions? It's not a signal-controlled intersection, because the same thing happens at those but worse.

I'd be interested in seeing what the crash history for Silver Springs looks like before the roundabout went in. Given the combination of "rural Nevada", "busy intersection at the transition from populated to unpopulated", and "at the bottom of a grade", I would expect it to be the same or higher.

Remember, in Nevada it is not unusual for rural drivers to straddle the centerline so they can exceed 100 mph more easily. Nobody finds anything wrong with this behavior because they're not around to see it. (And I bet if your daily drive involved US 50 you'd do it too.)

It's a much bigger question of how society treats those who does a wrong step. Most fatal crashes would involve some highly unusual circumstances, often driver doing something stupid like driving drunk at 2-3x seed limit.
Another conceptually similar situation is drug overdose. Should ER doctors waste time on those patients, for example?

[Scott5114]

It's a much bigger question of how society treats those who does a wrong step. Most fatal crashes would involve some highly unusual circumstances, often driver doing something stupid like driving drunk at 2-3x seed limit.
Another conceptually similar situation is drug overdose. Should ER doctors waste time on those patients, for example?

I'd personally much rather someone doing three times the speed limit plow into a rock than fifteen people.

The only direction I can see approaching the roundabout with any appreciable grade is the approach from the north. If an out-of-control vehicle were to proceed from that direction, after passing the roundabout they'd be entering the populated part of Silver Springs.

[kalvado]

It's a much bigger question of how society treats those who does a wrong step. Most fatal crashes would involve some highly unusual circumstances, often driver doing something stupid like driving drunk at 2-3x seed limit.
Another conceptually similar situation is drug overdose. Should ER doctors waste time on those patients, for example?

I'd personally much rather someone doing three times the speed limit plow into a rock than fifteen people.

The only direction I can see approaching the roundabout with any appreciable grade is the approach from the north. If an out-of-control vehicle were to proceed from that direction, after passing the roundabout they'd be entering the populated part of Silver Springs.

So would you rather have an overdose patient die before going on a criminal path?

As for ooc vehicles, it may be a good idea to train the concept of more controlled crash instead of maximum delay with severe consequences. I can think of a few major accidents in recent years where controlled drive off-road could be a much lesser evil.

[tradephoric]

I'd personally much rather someone doing three times the speed limit plow into a rock than fifteen people.

What if the person is a bus driver carrying 15 people?  The recent Coptic roundabout tragedy in Kenya claimed the lives of 26 people when a bus traveling too fast overturned at the roundabout (and just like the US50 & US95Alt roundabout the grade is around 7%).  Unfortunately this wasn't the first mass causality event at the Coptic roundabout and leaders have finally decided to permanently remove the roundabout.
 
KeNHA to permanently remove Kisumu's 'deadly' coptic roundabout
https://www.the-star.co.ke/news/2025-09-27-kenha-to-permanently-remove-kisumus-deadly-coptic-roundabout

[kphoger]

I'd personally much rather someone doing three times the speed limit plow into a rock than fifteen people.

So would you rather have an overdose patient die before going on a criminal path?

He didn't say that, so don't put words in his mouth.

Everybody, all the time, holds beliefs in tension that may seem to be at odds with each other.  While it's worthwhile to talk about out the logical inconsistency of such things, it really is unfair to accuse someone of believing something he doesn't actually believe just because you find them logically equivalent.

[kalvado]

I'd personally much rather someone doing three times the speed limit plow into a rock than fifteen people.

So would you rather have an overdose patient die before going on a criminal path?

He didn't say that, so don't put words in his mouth.

Everybody, all the time, holds beliefs in tension that may seem to be at odds with each other.  While it's worthwhile to talk about out the logical inconsistency of such things, it really is unfair to accuse someone of believing something he doesn't actually believe just because you find them logically equivalent.

I am comparing situations without blaming anyone. They are somewhat similar, although  in very different areas. There are enough inconsistencies in this life, but at least trying to explain the difference is a good idea.

[kphoger]

I'd personally much rather someone doing three times the speed limit plow into a rock than fifteen people.

What if the person is a bus driver carrying 15 people?

If a bus driver carrying fifteen people plows into fifteen people instead of a rock, then that would be a total of thirty.  So, still better.