Crash prone 'modern roundabouts'

[kphoger]

75-year-old woman killed in one-car Gorham roundabout

http://www.wlbz2.com/news/local/fatal-crash-closes-rte-114-bypass-in-gorham/434022792

So is this now a 'crash prone modern roundabout'?

Any intersection where a fatal crash is involved warrants further analysis.  Most would agree that one fatal crash is worse than 100 property damage only crashes.

But that doesn't make it crash-prone, any more than one fatal T-bone at a stoplight makes that intersection crash-prone.

A single accident does not a trend make.

[kalvado]

75-year-old woman killed in one-car Gorham roundabout

http://www.wlbz2.com/news/local/fatal-crash-closes-rte-114-bypass-in-gorham/434022792

So is this now a 'crash prone modern roundabout'?

Any intersection where a fatal crash is involved warrants further analysis.  Most would agree that one fatal crash is worse than 100 property damage only crashes.

But that doesn't make it crash-prone, any more than one fatal T-bone at a stoplight makes that intersection crash-prone.

A single accident does not a trend make.

Most intersections go for decades without a fatal event. And pretty often a fatal event is a solid, often the only convincing, reason to seriously reconsider design.  So one fatal accident is indeed one too many.

[tradephoric]

The IIHS website concedes there is a potential crash problem at two-lane roundabouts.   It's buried deep in the Q&A section about how roundabouts affect safety... at the very bottom.  When a pro-roundabout organization alludes to the potential crash problem at two-lane roundabouts, you know it's legitimate.  Crash rates of 1 MEV - a common crash rate at signalized intersections — seems unattainable at these complex double-lane roundabouts. 



Most people can deal with a slight increase in crashes at roundabouts if they reduce injury and fatal crashes — although a sixfold increase in crashes is hardly a slight increase.  Do we really believe roundabouts reduce injury and fatal crashes as much as they say?  My concern is certain types of roundabouts have exceedingly high crash rates and they aren't reducing injury and fatal crashes as much as the experts lead us to believe.

[jeffandnicole]

75-year-old woman killed in one-car Gorham roundabout

http://www.wlbz2.com/news/local/fatal-crash-closes-rte-114-bypass-in-gorham/434022792

So is this now a 'crash prone modern roundabout'?

Any intersection where a fatal crash is involved warrants further analysis.  Most would agree that one fatal crash is worse than 100 property damage only crashes.

But that doesn't make it crash-prone, any more than one fatal T-bone at a stoplight makes that intersection crash-prone.

A single accident does not a trend make.

Most intersections go for decades without a fatal event. And pretty often a fatal event is a solid, often the only convincing, reason to seriously reconsider design.  So one fatal accident is indeed one too many.

There was over 30,000 fatals last year. Compared to the previous few decades, it was a good year.  That would mean by your suggestion above there are nearly 30,000 sections of road that need reconstructing in just one year alone.

I'm pretty sure you're just trolling right now with such thoughts that a fatal at a roundabout, without knowing a single other thing in regards to the incident, requires a reconstruction.

[kalvado]

Most intersections go for decades without a fatal event. And pretty often a fatal event is a solid, often the only convincing, reason to seriously reconsider design.  So one fatal accident is indeed one too many.

There was over 30,000 fatals last year. Compared to the previous few decades, it was a good year.  That would mean by your suggestion above there are nearly 30,000 sections of road that need reconstructing in just one year alone.

I'm pretty sure you're just trolling right now with such thoughts that a fatal at a roundabout, without knowing a single other thing in regards to the incident, requires a reconstruction.

Well, there are definitely a lot of areas which may need improvement, and often authorities are reactive, not proactive..
But indeed, I know nothing about the spot in question. Moreover, local elderly driver going at high speed to an  intersection sounds as some sort of driver issue. However, I am equally not going to downplay single fatal event as a non-issue. Because at a rate of fatal accidents we get, single one does form a trend. To put things in perspective - for a town of Gorham size, that may very well be the only one for the year.

[kphoger]

The IIHS website concedes there is a potential crash problem at two-lane roundabouts.   It's buried deep in the Q&A section about how roundabouts affect safety... at the very bottom.  When a pro-roundabout organization alludes to the potential crash problem at two-lane roundabouts, you know it's legitimate.  Crash rates of 1 MEV - a common crash rate at signalized intersections — seems unattainable at these complex double-lane roundabouts. 



Most people can deal with a slight increase in crashes at roundabouts if they reduce injury and fatal crashes — although a sixfold increase in crashes is hardly a slight increase. 

Wow, congratulations on finding that!  Is this the first bit of evidence that anyone but us armchair geeks is actually acknowledging the safety distinction between single- and multi-lane roundabouts?  And no, a sixfold increase is no slight increase.

Do we really believe roundabouts reduce injury and fatal crashes...

Without the pursuant qualifying phrase, the answer would be 'yes.'  Chipping away at the claimed benefits does not dispel the benefits entirely.  The problem several of us have with your posting new blurbs one after the other is that you seem to be trying to offer evidence that all roundabouts are crash-prone.  This is not the way to do it, and I for one miss seeing the actual statistics you used to compile and post, showing what trends are actually happening at what locations.  I realize that probably took a lot of time and work but, failing that, linking to random news stories (for all I know generated by daily googling "roundabout accident") is not a good substitution.

...as much as they say?  My concern is certain types of roundabouts have exceedingly high crash rates and they aren't reducing injury and fatal crashes as much as the experts lead us to believe.

But the answer to this seems to be 'yes.'  Especially if recent roundabout installation is increasingly favoring the types of roundabouts that have higher crash rates, I'd say it's a mathematical certainty that the numbers are wrong.

Most would agree that one fatal crash is worse than 100 property damage only crashes.

I'm sure everyone would agree that one fatal crash is worse than two property damage only crashes.  However, I'm not certain most would agree that one fatal crash is worse than 100 property damage only crashes.  1 to 100 is a pretty big leap, and I'd warrant that most people would need to employ some critical thinking before coming to an agreement or not.  There is a line somewhere, the point at which the number of property damage only crashes is as bad as one fatal crash, and that line is going to be different for everyone and it obviously has to be drawn somewhere by those in charge of deciding what type of intersection to build.



In other news, I noticed there were two separate car crashes on the same three-mile stretch of westbound Kellogg (in Wichita) within three hours of each other yesterday.  This is not evidence that all six-lane divided freeways are crash-prone.  But it might be evidence that this particular stretch of six-lane divided freeway is crash-prone.

[jakeroot]

For what it's worth, in 2010, ~.006% of collisions involved a fatality (5,149,000 collisions compared to 32,999 fatalities). This data comes from the wiki page on US road fatalities.

If the current trends indicate anything, it's that one fatality for every 16,666 crashes is too many (based on Vision Zero movements lately).

[kalvado]

this is fucking bullshit http://currentincarmel.com/carmel-mayor-instructing-police-to-ticket-drivers-for-not-using-turn-signals-in-roundabouts
you should signal in a roundabout, but when it was voted down by the city counsel, and state law is ambiguous to the issue, you shouldn't proceed with ticketing!

Well, dealing with court is a punishment by itself. So even if no revenue is collected, (and many would just plead guilty to a lesser one - that would allow to raise funds for further construction), mayor would get it his way...

[Brian556]

Video of car hitting roundabout:
https://www.facebook.com/ICSLTSIF/videos/1531549346856434/

[tradephoric]

Distracted driver crashes into building in center of roundabout
https://www.villages-news.com/distracted-driver-crashes-building-center-roundabout/

Of the roughly 5000 roundabouts in America, five of them have buildings constructed in the central island (give or take a few).... we are now down to four.  Imagine the insurance premiums we would have if 1 in 5 buildings had cars plow through them.  According to the IIHS, the roundabout must have been malfunctioning since it didn't force the driver to slow down before plowing into the building.

[lordsutch]

I'm pretty sure neither the IIHS nor FHWA (nor any transportation agency in the world, for that matter) recommends putting a building in the middle of a roundabout.

Then again, if it wasn't a roundabout, I guess cars would be crashing into the building all the time since it would literally be in the middle of the intersection.

[jakeroot]

According to the IIHS, the roundabout must have been malfunctioning since it didn't force the driver to slow down before plowing into the building.

You're an idiot.

[intelati49]

According to the IIHS, the roundabout must have been malfunctioning since it didn't force the driver to slow down before plowing into the building.

You're an idiot.

Not an idiot, just a blockhead.

A blockhead specialising in freaking out over isolated incidents.

But he does have a point for increased crash rates for multi lane roundabouts. It's just the consensus right now is that it needs more research. (not just a "random" person datamining)

[jeffandnicole]

Wow...this was in the Villages, FL, where I was just vacationing 2 weeks ago!  In fact, we stayed at our friends house about a mile from here.  It's a huge golf cart community (which the person driving would be better off doing for a while).  They have a countless number of multilane roundabouts in the community, but a building within the roundabout is extremely unusual (and I have no clue what the purpose of the building would've been for).

That said...this isn't the only roundabout within the community with a building in the middle.  https://goo.gl/maps/HHJrqc6PmUu

Since we're talking about roundabouts, and a golf cart community, they've even installed roundabouts for golf carts!  Not too far away from this accident scene is this one:  https://goo.gl/maps/2db3xjE7UgL2 , and elsewhere in the Villages is this one: https://goo.gl/maps/YEW4x4FaedQ2

[kphoger]

Distracted driver crashes into building in center of roundabout
https://www.villages-news.com/distracted-driver-crashes-building-center-roundabout/

Of the roughly 5000 roundabouts in America, five of them have buildings constructed in the central island (give or take a few).... we are now down to four.  Imagine the insurance premiums we would have if 1 in 5 buildings had cars plow through them.  According to the IIHS, the roundabout must have been malfunctioning since it didn't force the driver to slow down before plowing into the building.

Good thing the car didn't T-bone another vehicle!  ~or~  Good thing it was a roundabout!

[tradephoric]

According to the IIHS, the roundabout must have been malfunctioning since it didn't force the driver to slow down before plowing into the building.

You're an idiot.

If I claimed that a red light forces drivers to stop, then you could call me an idiot.  In reality people blow through red lights just like they blow through roundabouts.  Now we can argue the likelihood of someone blowing through a red light vs. someone blowing through a roundabout, but it doesn't change the fact that the IIHS premise of why roundabouts are safer is flawed. 

[kphoger]

it doesn't change the fact that the IIHS premise of why roundabouts are safer is flawed. 

Again, fallacy of equivocation.  The most commonsense reading of the word "force" in the IIHS context is not a literal one.

[lordsutch]

If I claimed that a red light forces drivers to stop, then you could call me an idiot.  In reality people blow through red lights just like they blow through roundabouts.  Now we can argue the likelihood of someone blowing through a red light vs. someone blowing through a roundabout, but it doesn't change the fact that the IIHS premise of why roundabouts are safer is flawed. 

I guess in the semantic sense, a curve on a roadway doesn't force (in the coercive sense) the driver to actually turn the steering wheel. But I think in common parlance you'd say the curve forces the driver to turn the wheel.

For example, my students in a class have to complete a presentation for a certain percentage of their grade. I will not literally drag them in front of the class at gunpoint and make them give a presentation on pain of death, but nonetheless I think the statement "I force my students to give a presentation in class" would be reasonably interpreted as "if they don't do it, there will be bad consequences for their grades."

Would you be satisfied if the verb "force to do X" was replaced with "strongly encourage a conscious, attentive driver to do X, given that failing to do so would subject one to a high risk of death, injury, and/or totaling one's vehicle"? Blowing through red lights and not following the course of the roadway (i.e. continuing straight ahead rather than turning) on entry to a roundabout would seem to fall into the same category there.

[tradephoric]

I guess in the semantic sense, a curve on a roadway doesn't force (in the coercive sense) the driver to actually turn the steering wheel. But I think in common parlance you'd say the curve forces the driver to turn the wheel.

For example, my students in a class have to complete a presentation for a certain percentage of their grade. I will not literally drag them in front of the class at gunpoint and make them give a presentation on pain of death, but nonetheless I think the statement "I force my students to give a presentation in class" would be reasonably interpreted as "if they don't do it, there will be bad consequences for their grades."

Would you be satisfied if the verb "force to do X" was replaced with "strongly encourage a conscious, attentive driver to do X, given that failing to do so would subject one to a high risk of death, injury, and/or totaling one's vehicle"? Blowing through red lights and not following the course of the roadway (i.e. continuing straight ahead rather than turning) on entry to a roundabout would seem to fall into the same category there.

A student could blow off your presentation assignment, giving you the middle finger as they walk out of class.  Or a suicidal person could purposely drive through the middle of a roundabout at 100 mph, launching 50 feet into the air after striking the central island curbing.  A passing grade and the preservation of life is usually enough encouragement to prevent these things from happening... but not always.  In the example of a suicidal individual, the tight circle of a roundabout actually encourages them to speed up, not slow down.  Taken literally, the idea that roundabouts "force" drivers to slow down is pure lunacy.

The public has been conditioned to believe that roundabouts are always the safest alternative.  The IIHS is perpetuating that myth by saying that roundabouts "force" drivers to slow down.  Only a fool would argue that red lights force drivers to stop, but it's somehow OK for the IIHS to argue that roundabouts force drivers to slow down?  Just try to convince the family members of the two men killed in Gainsville on Tuesday that the roundabout forced the driver to slow down. 

Roundabout crash kills two, police say
http://www.gainesville.com/news/20170502/roundabout-crash-kills-two-police-say

People are encouraged to slow down at a roundabout just like they are encouraged to stop at a red light.  Had the IIHS said that the tight circle of a roundabout only "encourages" drivers to slow down, then roundabouts would be at the same level as traffic signals - where if you ignore the encouragement a deadly crash can occur.  At that point who's to say what type of intersection is safer?  The IIHS didn't want that.

[DaBigE]

I guess in the semantic sense, a curve on a roadway doesn't force (in the coercive sense) the driver to actually turn the steering wheel. But I think in common parlance you'd say the curve forces the driver to turn the wheel.

For example, my students in a class have to complete a presentation for a certain percentage of their grade. I will not literally drag them in front of the class at gunpoint and make them give a presentation on pain of death, but nonetheless I think the statement "I force my students to give a presentation in class" would be reasonably interpreted as "if they don't do it, there will be bad consequences for their grades."

Would you be satisfied if the verb "force to do X" was replaced with "strongly encourage a conscious, attentive driver to do X, given that failing to do so would subject one to a high risk of death, injury, and/or totaling one's vehicle"? Blowing through red lights and not following the course of the roadway (i.e. continuing straight ahead rather than turning) on entry to a roundabout would seem to fall into the same category there.

A student could blow off your presentation assignment, giving you the middle finger as they walk out of class.  Or a suicidal person could purposely drive through the middle of a roundabout at 100 mph, launching 50 feet into the air after striking the central island curbing.  A passing grade and the preservation of life is usually enough encouragement to prevent these things from happening... but not always.  In the example of a suicidal individual, the tight circle of a roundabout actually encourages them to speed up, not slow down.  Taken literally, the idea that roundabouts "force" drivers to slow down is pure lunacy.

The public has been conditioned to believe that roundabouts are always the safest alternative.  The IIHS is perpetuating that myth by saying that roundabouts "force" drivers to slow down.  Only a fool would argue that red lights force drivers to stop, but it's somehow OK for the IIHS to argue that roundabouts force drivers to slow down?  Just try to convince the family members of the two men killed in Gainsville on Tuesday that the roundabout forced the driver to slow down. 

Where's the thread devoted to crash-prone railroad crossings? Lights, bells, and gates don't "force" you to stop, yet are arguably more dangerous/deadly than a roundabout. What's the solution when a crossing has passive warning devices (signs only)? Put up signals and gates...same silver-bullet crash fix mentality that roundabout installations have been claimed here to have been peddled to the public. The same suicidal person can blow-through a gate (hell, they're designed to break away) and smash right into a passing train, possibly into a car transporting hazardous materials.

ANYTHING, even "properly designed" when not used properly can have deadly consequences.

[kphoger]

Taken literally, ...

You seem to be the only one on here who does, though.

[tradephoric]

Ultimately, if the argument is roundabouts force drivers to slow down then by the same logic red lights force drivers to stop.  Of course neither argument is true.  People blow through red lights and get into deadly crashes and people blow through the center of roundabouts and get into deadly crashes.  Without knowing the rate of these deadly crashes for each intersection type, how can the IIHS claim that roundabouts are safer than traffic signals?  By arguing that roundabouts force drivers to slow down the IIHS completely downplaying the possibility of a driver blowing through the center of the roundabout at high speeds.   It's easy to argue that roundabouts are safer than traffic signals when you start with the premise that everyone traveling through a roundabout is driving slowly.  The problem is their whole premise is wrong (the double fatality crash at the Gainsville roundabout is evidence of this). 

[jeffandnicole]

The whole premise of Who Wants To Be A Millionaire is that the people on the show want to be a millionaire.  The premise is the contestants will answer 15 questions correctly and win a million dollars.  The problem is their whole premise is wrong (you can stop at any point and take home the money you already won).  Thus, all of television is incorrect and we should explode into a fireball of grass clippings.

[lordsutch]

We know the rate of deadly crashes at signalized intersections versus roundabouts: there's empirical data on the point, from jurisdictions all over the world. There's no need to base the safety claim on whether or not drivers actually are forced to slow down or whether or not they obey traffic signals; it can be derived from simple observation of fatality incidence over time, without a causal argument.

The argument you seem to be making, out of your infatuation with Dearborn-style evenly spaced grid streets with wide medians, signalized intersections, and "green wave" progression timing in every direction (a situation that obtains in the Detroit area and virtually nowhere else in the country, since most grids are irregular due to either the local geographic features or historical development patterns), is that since collisions are not completely preventable, it really doesn't matter what intersection design is used at a particular location since accidents are inevitable, and any effort to reduce crash fatality rates or severity should take a back seat to the potential efficiency of evenly-spaced arterial grids with Michigan lefts.

[kalvado]

We know the rate of deadly crashes at signalized intersections versus roundabouts: there's empirical data on the point, from jurisdictions all over the world. There's no need to base the safety claim on whether or not drivers actually are forced to slow down or whether or not they obey traffic signals; it can be derived from simple observation of fatality incidence over time, without a causal argument.

The argument you seem to be making, out of your infatuation with Dearborn-style evenly spaced grid streets with wide medians, signalized intersections, and "green wave" progression timing in every direction (a situation that obtains in the Detroit area and virtually nowhere else in the country, since most grids are irregular due to either the local geographic features or historical development patterns), is that since collisions are not completely preventable, it really doesn't matter what intersection design is used at a particular location since accidents are inevitable, and any effort to reduce crash fatality rates or severity should take a back seat to the potential efficiency of evenly-spaced arterial grids with Michigan lefts.

Well, anecdotal fact: we had a high traffic intersection replaced with roundabout nearby. After that traffic reduced due to relocation of some offices (not related to construction). Pre-construction documents showed 0 fatal accidents over 10 years. There was 1 in 5 years after construction
Is that a statistically significant trend? No, because 0 and 1 are within statistical error margin. You really need high volume data, which is pretty much impossible to collect without being able to access all raw statistics and probably changing report forms...

What Trade is doing by bringing individual crash reports is beyond me. But he mentioned significant number of high-crash rate sites... Which is statistically significant piece of information.
I didn't see proper statistics of fatal accidents. Claiming that "there are almost no fatalities" is clearly rebutted by Trade's  accident reports, though. It doesn't matter if accident is weird one-off. Almost all fatal accidents are such these days, and same situations contribute towards traffic light and stop/yield controlled locations.