Crash prone 'modern roundabouts'

[cjw2001]

Based on the Google Maps measurement tool, the retaining wall is a full 45 feet away from the inner curb of the roundabout.   The probability of screwing up and ending up against the retaining wall at normal speeds is extremely unlikely.  (The posted warning sign has an advisory speed of 15 mph, even at double that speed you would have to really work at it to end up in the center of the roundabout.  At least one of the fatal crashes that he quotes involved an intoxicated driver at extremely high speeds.  Normal drivers are not as risk here. 

https://www.google.com/maps/@39.9280968,-86.1268644,3a,75y,183.26h,90.9t/data=!3m6!1e1!3m4!1sZtBXbeeSszxK9vR7zeH4Vg!2e0!7i13312!8i6656

[tradephoric]

Stop blaming the roundabout and start blaming the person driving drunk at high speed.  The Carmel roundabouts have been a wonderful improvement to traffic flow in the area.   A driver going far in excess of speed limits and driving impaired is not an indictment of the roundabout, it's a failure of personal responsibility.  Get over it.

According to Jim Brainard, if you straightened all of the roundabouts in Carmel and strung them together, you'd have to drive about 10 ½ miles to reach the end.... or a little over 4 laps around Indianapolis Motor Speedway.  That's 10 ½ miles where drivers are not traveling in a straight line to get to their destination.  Also, according to the IIHS drivers encountering a roundabout are FORCED to slow down.  So even if nobody else is in the roundabout, Carmel drivers are guaranteed to experience several seconds of delays as they slow down to traverse the circle.  And we aren't even considering the "problem"  roundabouts that can take several minutes to traverse during rush hour.  CJW is conveniently ignoring those.  Drivers collectively driving 10 ½ miles out of their way... guaranteed delays at every roundabout drivers traverse... that doesn't sound like improved traffic flow. 

To be honest, I'm sure there was an improvement in traffic flow in Carmel after the roundabouts were built.   But could that be because the intersections the roundabouts replaced were woefully inadequate to carry the capacity of a ballooning Carmel population?  Here are some before/after pictures of roundabout location in Carmel.  Not surprising traffic flow improved when you compare these pictures... not to mention the fact the two major surface streets in Carmel were converted to grade-separated freeways over the past decade.

[kalvado]

Stop blaming the roundabout and start blaming the person driving drunk at high speed.  The Carmel roundabouts have been a wonderful improvement to traffic flow in the area.   A driver going far in excess of speed limits and driving impaired is not an indictment of the roundabout, it's a failure of personal responsibility.  Get over it.

According to Jim Brainard, if you straightened all of the roundabouts in Carmel and strung them together, you’d have to drive about 10 ½ miles to reach the end…. or a little over 4 laps around Indianapolis Motor Speedway.  That’s 10 ½ miles where drivers are not traveling in a straight line to get to their destination.  Also, according to the IIHS drivers encountering a roundabout are FORCED to slow down.  So even if nobody else is in the roundabout, Carmel drivers are guaranteed to experience several seconds of delays as they slow down to traverse the circle.  And we aren’t even considering the “problem” roundabouts that can take several minutes to traverse during rush hour.  CJW is conveniently ignoring those.  Drivers collectively driving 10 ½ miles out of their way… guaranteed delays at every roundabout drivers traverse… that doesn’t sound like improved traffic flow. 

To be honest, I’m sure there was an improvement in traffic flow in Carmel after the roundabouts were built.   But could that be because the intersections the roundabouts replaced were woefully inadequate to carry the capacity of a ballooning Carmel population?  Here are some before/after pictures of roundabout location in Carmel.  Not surprising traffic flow improved when you compare these pictures… not to mention the fact the two major surface streets in Carmel were converted to grade-separated freeways over the past decade.

And here you're not quite right. Roundabouts should be compared not with straight road, but either with 4-way stops or traffic signals. Both of those options include delays. You may include grade separated intersections as a no-delay option, but then you're talking about entirely different price range.

And yes, throughput of roundabouts at high traffic rate are yet another question waiting to be addressed.

[kphoger]

we (as a society) have a responsibility to create an environment whereby screwing up doesn't kill you.

Disagree.

I'd say we as a society have a responsibility to create an environment in which people don't assume that screwing up won't kill them.

Roundabouts should be compared ... with 4-way stops or traffic signals. Both of those options include delays.

Agree.

And yes, throughput of roundabouts at high traffic rate are yet another question waiting to be addressed.

Also agree.

[intelati49]

we (as a society) have a responsibility to create an environment whereby screwing up doesn't kill you.

Disagree.

I'd say we as a society have a responsibility to create an environment in which people don't assume that screwing up won't kill them.

Roundabouts should be compared ... with 4-way stops or traffic signals. Both of those options include delays.

Agree.

And yes, throughput of roundabouts at high traffic rate are yet another question waiting to be addressed.

Also agree.

I'll take the middle road (heh, unintentional) on this one. Yes, having a concrete wall unprotected in the middle of the road is dumb. But no, if you have good signage and clear sightlines it isn't much of a problem. (Don't have a reference to check the clear space numbers.)

Yes

Yes

I love this topic from a theoretical standpoint, but not every rollover crash and accident is a mark on roundabouts in general. The rash of crashes after the construction should be grounds for the engineer to go "Whoa, hold up, what's going on." Just don't call for the removal of everything at once.

[kalvado]

I love this topic from a theoretical standpoint, but not every rollover crash and accident is a mark on roundabouts in general. The rash of crashes after the construction should be grounds for the engineer to go "Whoa, hold up, what's going on." Just don't call for the removal of everything at once.

Another way of looking at it (and it is called "statistics") is to assume that shit happens, and crashes -  horrible or mundane - can happen at any point of the road, and are even more likely at the intersection.
However if some of those locations (or type of locations) stands out in terms of number of events, then...

[intelati49]

I love this topic from a theoretical standpoint, but not every rollover crash and accident is a mark on roundabouts in general. The rash of crashes after the construction should be grounds for the engineer to go "Whoa, hold up, what's going on." Just don't call for the removal of everything at once.

Another way of looking at it (and it is called "statistics") is to assume that shit happens, and crashes -  horrible or mundane - can happen at any point of the road, and are even more likely at the intersection.
However if some of those locations (or type of locations) stands out in terms of number of events, then...

Whoa, hold up

Get more data and start looking at it.

[tradephoric]

I love this topic from a theoretical standpoint, but not every rollover crash and accident is a mark on roundabouts in general.

When you crash head on into a retaining wall at 62 mph you are pretty much a goner - which is the circumstances behind the 2007 double-fatality crash at the 96th and Westfield roundabout.  At least you can survive a spectacular rollover crash.  Case in point watch this video of 100 spectacular NASCAR flips.  All of these drivers have one thing in common... they walked away from the crash.  And a lot of these crashes were from the early days of NASCAR where safety wasn't where it is today.

https://www.youtube.com/watch?v=a5xc8pDMA7c

[kalvado]

I love this topic from a theoretical standpoint, but not every rollover crash and accident is a mark on roundabouts in general.

When you crash head on into a retaining wall at 62 mph you are pretty much a goner - which is the circumstances behind the 2007 double-fatality crash at the 96th and Westfield roundabout.  At least you can survive a spectacular rollover crash.  Case in point watch this video of 100 spectacular NASCAR flips.  All of these drivers have one thing in common... they walked away from the crash.  And a lot of these crashes were from the early days of NASCAR where safety wasn't where it is today.

If you enter an traffic light controlled intersection at 62 MPH at a wrong time and live to tell that story - you may also buy a couple of lottery tickets.

[jakeroot]

we (as a society) have a responsibility to create an environment whereby screwing up doesn't kill you.

Disagree.

I'd say we as a society have a responsibility to create an environment in which people don't assume that screwing up won't kill them.

I think both go hand in hand. Improve driver confidence by creating a safer environment.

Of course, I wish that weren't true. I'd rather drivers were confident because they were well-taught, but the US seems incapable of implementing even a slightly difficult driving exam.

[tradephoric]

$1.1M project will change crash-prone Lee Road roundabout

A rendering GHD Incorporated created for the Livingston County Road Commission shows how the roundabout at Lee and Whitmore Lake roads in Green Oak Township will be reduced from three lanes to two lanes. (Photo: Submitted)

"We need to reduce the number of conflict points where people wander into other lanes and make quick adjustments inside the roundabout, because people turning from the wrong lane causes the majority of the crashes,"  Livingston County Road Commission Manager Mike Craine said.

"We are also improving pavement markings and signs, because it's a little confusing," Craine said.

"Most of the crashes on Lee Road happen in this roundabout, usually between 40 to 60 a year,"  traffic and safety engineer Mike Goryl said. "More lanes means more problems. Across the state, when you have three lanes in a roundabout, we see similar crash patterns."

http://www.livingstondaily.com/story/news/local/community/livingston-county/2018/01/08/1-1-m-project-change-crash-prone-lee-road-shrinking-3-lane-roundabout-lee-road-reduce-crashes-confus/988173001/

[jeffandnicole]

we (as a society) have a responsibility to create an environment whereby screwing up doesn't kill you.

Disagree.

I'd say we as a society have a responsibility to create an environment in which people don't assume that screwing up won't kill them.

I think both go hand in hand. Improve driver confidence by creating a safer environment.

Of course, I wish that weren't true. I'd rather drivers were confident because they were well-taught, but the US seems incapable of implementing even a slightly difficult driving exam.

The US has done a lot to eliminate distractions, including limiting the number of people permitted in a car with a new driver, longer probationary periods, etc.

But, if a 16 year old is taught to stop before entering the highway, immediately get in the left lane going 20 below the limit, or they don't have to slow down at a yield sign, they're still not going to be good drivers.

[kphoger]

I love this topic from a theoretical standpoint, but not every rollover crash and accident is a mark on roundabouts in general.

When you crash head on into a retaining wall at 62 mph you are pretty much a goner - which is the circumstances behind the 2007 double-fatality crash at the 96th and Westfield roundabout.  At least you can survive a spectacular rollover crash.  Case in point watch this video of 100 spectacular NASCAR flips.  All of these drivers have one thing in common... they walked away from the crash.  And a lot of these crashes were from the early days of NASCAR where safety wasn't where it is today.

If you enter an traffic light controlled intersection at 62 MPH at a wrong time and live to tell that story - you may also buy a couple of lottery tickets.

But the probability of entering a traffic light-controlled intersection at a wrong time is less than 100%.  The point is that the probability or hitting a retaining wall at a wrong time is exactly 100%.

[kalvado]

I love this topic from a theoretical standpoint, but not every rollover crash and accident is a mark on roundabouts in general.

When you crash head on into a retaining wall at 62 mph you are pretty much a goner - which is the circumstances behind the 2007 double-fatality crash at the 96th and Westfield roundabout.  At least you can survive a spectacular rollover crash.  Case in point watch this video of 100 spectacular NASCAR flips.  All of these drivers have one thing in common... they walked away from the crash.  And a lot of these crashes were from the early days of NASCAR where safety wasn't where it is today.

If you enter an traffic light controlled intersection at 62 MPH at a wrong time and live to tell that story - you may also buy a couple of lottery tickets.

But the probability of entering a traffic light-controlled intersection at a wrong time is less than 100%.  The point is that the probability or hitting a retaining wall at a wrong time is exactly 100%.

My message is somewhat different - sometimes you cannot avoid a problem when someone is determined to get into trouble. As someone said,

... a race between engineers striving to build bigger and better idiot-proof things, and the Universe trying to produce bigger and better idiots. So far, the Universe is winning.

Sometimes you cannot avoid a problem when someone is determined to get into trouble. But minimizing consequences is another possible strategy. No need to put a hard stop where it is less than needed, but sometimes running against concrete wall is better than flying over the edge into an abyss.
Roundabouts with all their "calming"  approaches, "visibility control", etc do not have room for adjustments and they remove many traditional hints for drivers helping them to become idiots. In other words, sometimes universe wins by coming up with idiots in engineering positions.

[tradephoric]

^^
Laughs aside, he's (Jim Brainard) basically dictator of the public works department in Carmel, IN. There's very little free thinking in that office, me thinks.

Wow you aren't kidding about not much free thinking.  A Carmel city counsel meeting has recently surfaced on youtube.

https://youtu.be/a3Cla9t9UZk

[jakeroot]

^^
Laughs aside, he's (Jim Brainard) basically dictator of the public works department in Carmel, IN. There's very little free thinking in that office, me thinks.

Wow you aren't kidding about not much free thinking.  A Carmel city counsel meeting has recently surfaced on youtube.

https://youtu.be/a3Cla9t9UZk

HA! Credit where credit's due...that's hilarious. Probably accurate too.

[webny99]

I would be interested in a brief summary of what, exactly, has kept this thread going for over 60 pages.
It's not a bad topic, but after a while, you'd have to start going in circles 

[jakeroot]

I would be interested in a brief summary of what, exactly, has kept this thread going for over 60 pages.
It's not a bad topic, but after a while, you'd have to start going in circles 

We do start to go in circles, but each time we do, some new piece of information comes up, or one of us changes their mind about something, etc. Keeps the conversation going.

Personally, in the roadgeek spectrum, traffic control is my main interest, so naturally, I could endlessly debate the pros and cons of roundabouts.

[DaBigE]

I would be interested in a brief summary of what, exactly, has kept this thread going for over 60 pages.
It's not a bad topic, but after a while, you'd have to start going in circles 

Some think roundabouts are evil and all should be tore out asap. Some think engineers who design them should lose their license to practice. Some think roundabouts are the only intersection control device modern traffic engineers/DOTs will consider. Some multilane roundabouts have seen a sharp increase in minor injury/fender-bender crashes for various reasons, including but not limited to: poor geometric design, improper signing/marking, over-designed/under-capacity (too many lanes), poor driving habits, lax driver education, too many drunks. Fatalities have occurred, but the overwhelming majority have been attributed to OWI, operating too fast, or a fixed object in the central island. For the past several (tens of?) pages, the only new "information" being posted in this thread is another report of a crash at a roundabout.

I think that about sums it up.

[jeffandnicole]

I would be interested in a brief summary of what, exactly, has kept this thread going for over 60 pages.
It's not a bad topic, but after a while, you'd have to start going in circles 

Tradephoric hates multi-lane roundabouts.

Kalvado hates all roundabouts.

[kalvado]

Kalvado hates all roundabouts.

You're cutting a corner here.
Kalvado hates, when things are done just for sake of doing it "cool" without understanding. Most roundabouts I saw are built because they are cool, without underlying understanding. Hence...

[tradephoric]

I would be interested in a brief summary of what, exactly, has kept this thread going for over 60 pages.
It's not a bad topic, but after a while, you'd have to start going in circles 

Simple really.  Agencies continue to build complex modern roundabouts.  As long as agencies continue to build them there will inevitably be more crash prone modern-roundabouts to cite.  To the chagrin of DaBigE, I'll continue to cite them.  Maybe if a roundabout hits 1,000 crashes in a year, people will finally start to question if these roundabouts are working. To get that number of crashes, they would probably have to design a 4x3 roundabout... but knowing the ignorance of these agencies they might just try to do it.  It will be the most crash prone intersection in the world, yet they will be claiming how safe it is! 

[webny99]

After a while, you'd have to start going in circles 

We do start to go in circles, but each time we do, some new piece of information comes up, or one of us changes their mind about something, etc. Keeps the conversation going.

Good response to a good pun
How, then, does reading this thread compare to continuously circling a roundabout?

Simple really.  Agencies continue to build complex modern roundabouts.  As long as agencies continue to build them there will inevitably be more crash prone modern-roundabouts to cite.  To the chagrin of DaBigE, I'll continue to cite them.  Maybe if a roundabout hits 1,000 crashes in a year, people will finally start to question if these roundabouts are working. To get that number of crashes, they would probably have to design a 4x3 roundabout... but knowing the ignorance of these agencies they might just try to do it.  It will be the most crash prone intersection in the world, yet they will be claiming how safe it is! 

Are all of your 1300 posts in this thread? It is theoretically possible, since there are 1600 replies 

Though multi-lane roundabouts can be annoying due to driver ignorance and hesitation, I fail to see how they are, functionally, any different from a standard one-lane roundabout.

[MNHighwayMan]

I fail to see how they are, functionally, any different from a standard one-lane roundabout.

I suspect you will learn, here, within the next day.

[kalvado]

Though multi-lane roundabouts can be annoying due to driver ignorance and hesitation

Age: 18

I hate to ask, but how long do you have your license, Mr. Experienced Driver?