Crash prone 'modern roundabouts'

[Rothman]

Seems to me that there might have been a reporting change between 2013 and 2014. Quite the big data jump without an explanation of all the contributing factors.

[7/8]

Seems to me that there might have been a reporting change between 2013 and 2014. Quite the big data jump without an explanation of all the contributing factors.

For the Homer Watson/Block Line roundabout, the increase in crashes is likely due to the opening of the Block Line Rd bridge on Nov 22nd, 2013:
http://www.therecord.com/news-story/4230728-new-block-line-road-bridge-opening-friday-in-kitchener/

The bridge, location shown below, provides a useful E-W link between Homer Watson and Courtland Rd/Fairway Rd

[tradephoric]

http://wishtv.com/2015/10/08/roundabouts-may-confuse-but-stats-back-up-their-safety/

My favorite quote(s):

And even if you make a mistake, because speeds are so slow, most wrecks don't involve serious injuries....[Carmel Mayor Jim Brainard] points out that because accidents and injuries are down in Carmel, insurance rates have dropped. He says the city doesn't have a full "jaws of life"  crew in its fire department anymore because they don't have the high speed impacts that they used to have and don't need them very often.

Total accidents and injury crashes have gone up in Carmel since that quote.  The number of injury crashes has risen 56% in Carmel over the past 6 years.  In addition the only two fatal crashes that occurred in Carmel in 2014 happened at roundabouts.  A lot of good it did not having a full "jaws of life"  crew.  Let's all give Jim Brainard a hand for making his city so safe.     

[epzik8]

Did anyone mention Maryland's Hampstead Bypass? I clinched Maryland Route 30 this month - I went straight from Reisterstown to Hanover, PA - and on the Hampstead Bypass, a car with a Pennsylvania plate whose driver was obviously headed to Hanover started to exit onto MD-482 east, then suddenly switched lanes right in front of me to stay on MD-30 north. It's a two-lane circle with the left lane in each direction at every circle intended for drivers staying on MD-30. Problem is, some drivers don't realize that and will then cut in front of you to avoid making a wrong turn onto 482 or Business 30 or whatever the cross street of that other circle is.

Honorable mention to the two-lane circle at U.S. 15 and MD-464 in Point of Rocks. Also to the pair of U.S. 15/U.S. 50 circles in Loudoun County, Virginia.

[7/8]

Manufacturers are designing bulky a-pillar in a quest to receive five star safety ratings.  Do bulky A-pillar designs reduce driver visibility and lead to drivers pulling out into the roundabout thinking it's clear when it's not?  The curves of a roundabout can make it easy for a vehicle to get lost in the a-pillar.


http://www.safespeed.org.uk/bike005.pdf

This is my biggest complaint about my current car, the Dodge Caliber. The pillars definitely reduce visibility. But I don't find them too bad with roundabouts; I find making left turns the worst, since pedestrians can easily "hide" behind them. I have to move head to see behind the pillars to make sure no one's there.

[AlexandriaVA]

Progress continutes. Carmel continues to build (http://fox59.com/2016/06/01/32-new-roundabouts-coming-to-carmel-timing-of-the-plan-outlined/)

"The vast majority of the money is going to improving our transportation system. Making it safer number one and then number two making it easier and quicker for people to get around," Mayor Jim Brainard said.

Mayor Brainard says the roundabouts make the city appealing.

"That's how we compete. That's how we attract business to the city of Carmel."

[tradephoric]

^The only two fatal crashes that occurred in Carmel in 2014 occurred at roundabouts.  What does Mayor Jim Brainard have to say about that?  Doesn't really fit into his PR campaign. 

[cjw2001]

^The only two fatal crashes that occurred in Carmel in 2014 occurred at roundabouts.  What does Mayor Jim Brainard have to say about that?  Doesn't really fit into his PR campaign.

It's time to stop blaming the roundabout for drunk and / or speeding drivers.   There will be impaired drivers regardless of the road topology.   The fact that these intersections were roundabouts had little to do with the incidents in question.

[AlexandriaVA]

^The only two fatal crashes that occurred in Carmel in 2014 occurred at roundabouts.  What does Mayor Jim Brainard have to say about that?  Doesn't really fit into his PR campaign.

What about 2015 crash data? My guess is that it doesn't support your position so you decided to omit it.

Yes, fine people of the heartland, roundabouts are fine and will not eat you or your children. There is more to driving than stoplights or four-way stops.

[tradephoric]

Alcohol was a factor in one of the fatal Carmel crashes in 2014. According to the NHTSA, there were 9,967 people killed in alcohol-impaired-driving crashes in 2014.  This accounted for 31 percent of all motor vehicle traffic fatalities in the United States that year.  The point is alcohol is a contributing factor to a LOT of fatal crashes; whether they happen at a roundabout, signalized intersection, or on the freeway.   

The national numbers on roundabouts suggest that they reduce fatal crashes by 90%.  These numbers obviously include fatal crashes involving alcohol.  If Carmel had 2 fatal crashes at their 100 roundabouts, you would expect to see roughly 20 fatal crashes throughout the rest of the city (Carmel does have its fair share of signalized intersections still.. someone just posted an article where 32 more roundabouts are planned, many of which will be replacing signalized intersections).

What about 2015 crash data? My guess is that it doesn't support your position so you decided to omit it.
Yes, fine people of the heartland, roundabouts are fine and will not eat you or your children. There is more to driving than stoplights or four-way stops.

You are suggesting that the 2014 Carmel crash data isn't statistically significant by itself.  Just think of the hundreds of thousands of miles driven on Carmel roads in 2014.  Yet the only fatal crashes happened at roundabouts which are supposedly the safest places to be driving.  How is it that nobody was killed by some drunk at a signalized intersection (yes, they still exist in Carmel!)?  Or could it be, just maybe, that roundabouts don't reduce fatal crashes as much as they want us to believe?

[AlexandriaVA]

I thought it was because roundabouts are too difficult for Midwesterners to negotiate (as in you don't drive over them, or stop and make a left or right hand turn, etc etc).

[kalvado]

What about 2015 crash data? My guess is that it doesn't support your position so you decided to omit it.
Yes, fine people of the heartland, roundabouts are fine and will not eat you or your children. There is more to driving than stoplights or four-way stops.

You are suggesting that the 2014 Carmel crash data isn't statistically significant by itself.  Just think of the hundreds of thousands of miles driven on Carmel roads in 2014.  Yet the only fatal crashes happened at roundabouts which are supposedly the safest places to be driving.  How is it that nobody was killed by some drunk at a signalized intersection (yes, they still exist in Carmel!)?  Or could it be, just maybe, that roundabouts don't reduce fatal crashes as much as they want us to believe?

Problem is that road statistics - especially accident statistics - and especially fatal accident data - is usually statistically insignificant to begin with. If you have a 10% accident reduction from 100 to 90, all you can say is that there is no statistically significant difference. No DOT would ignore the change, though.
  Some multiyear national trends may go better than error bars, but most of it is... well, if you don't have the data you like - you have to like the data you have.

[tradephoric]

I thought it was because roundabouts are too difficult for Midwesterners to negotiate (as in you don't drive over them, or stop and make a left or right hand turn, etc etc).

You might be onto something.  The Midwest states are highlighted yellow as defined by the US Census Bureau.  The pink circles represent roundabouts that have 3 circulating lanes on at least one approach.  These are some of the most complex roundabouts that have been built in the United States.  As you can see, the majority of the complex roundabouts are located in the Midwest (specifically Wisconsin & Michigan).  So are the roundabouts too difficult for Midwestern drivers, or are they just being asked to navigate roundabouts that are more complex than the rest of the country? 



One interesting note... most of the regions in Wisconsin now have a moratorium on designing roundabouts with 3 circulating lanes.  Other state agencies should look closely at how triple lane roundabouts have evolved in Wisconsin before deciding to build a triple lane roundabout of their own.  In addition, several of the triple lane roundabouts in Michigan have since been downsized to only two-lanes with other roundabout downsizing planned (ie. Lee Road Roundabout).

[AlexandriaVA]

I thought Midwesterners like wide roads, so it would follow that the roundabouts should be wide as well.

[jakeroot]

I thought Midwesterners like wide roads, so it would follow that the roundabouts should be wide as well.

That's a pretty good point. Wisconsin in particular seems to have a large number of divided highways, ripe for three lane roundabouts. Same for Michigan.

[jeffandnicole]

The national numbers on roundabouts suggest that they reduce fatal crashes by 90%.  These numbers obviously include fatal crashes involving alcohol.  If Carmel had 2 fatal crashes at their 100 roundabouts, you would expect to see roughly 20 fatal crashes throughout the rest of the city...

No you wouldn't. Two issues with this:

You're looking at national numbers.  You're only looking at averages.  Not every single city, town, state, etc is going to see the same reduction.  In some states, there may be no reduction, in other states there could be a 100% reduction.  The *average* is a 90% reduction (at least what we're told).

And two, you can't take the number and say what the rest of the city/state should have had. If there were 0 DUI accidents at the roundabout (let's say that happened in 2015 because you ignored that data), then 90% would equal 0 DUI deaths in the rest of the city as well.  Is that true?  Probably not.

[tradephoric]

And two, you can't take the number and say what the rest of the city/state should have had. If there were 0 DUI accidents at the roundabout (let's say that happened in 2015 because you ignored that data), then 90% would equal 0 DUI deaths in the rest of the city as well.  Is that true?  Probably not.

According to the Carmel, Indiana Police Department there was only 1 fatal crash in 2015 (and it did not occur at a roundabout).  I posted this data in chart form a few posts up, so I don't see how I'm "ignoring"  the data.  I gave you the source of the data and the number of fatalities that occurred in 2015 already (see Reply #552).  You were welcome to look up the data for yourself instead of relying on me.

There was another fatal roundabout crash in March of 2016:
http://www.indystar.com/story/news/crime/2016/03/18/driver-killed-carmel-roundabout-crash/81967984/

This was the first fatal crash to occur in Carmel in 2016.  So over a 27 month period, 3 of the 4 fatal crashes that occurred in Carmel happened at roundabouts.  Either the rest of Carmel's street network is incredibly safe, or their roundabouts are much more dangerous than the roundabouts analyzed in the national studies.  The third option is you can just try to discredit the numbers and make an ineffective argument that 27 months isn't statistically significant.

[jeffandnicole]

And two, you can't take the number and say what the rest of the city/state should have had. If there were 0 DUI accidents at the roundabout (let's say that happened in 2015 because you ignored that data), then 90% would equal 0 DUI deaths in the rest of the city as well.  Is that true?  Probably not.

According to the Carmel, Indiana Police Department there was only 1 fatal crash in 2015 (and it did not occur at a roundabout).  I posted this data in chart form a few posts up, so I don’t see how I’m “ignoring” the data.  I gave you the source of the data and the number of fatalities that occurred in 2015 already (see Reply #552).  You were welcome to look up the data for yourself instead of relying on me.

There was another fatal roundabout crash in March of 2016:
http://www.indystar.com/story/news/crime/2016/03/18/driver-killed-carmel-roundabout-crash/81967984/

This was the first fatal crash to occur in Carmel in 2016.  So over a 27 month period, 3 of the 4 fatal crashes that occurred in Carmel happened at roundabouts.  Either the rest of Carmel’s street network is incredibly safe, or their roundabouts are much more dangerous than the roundabouts analyzed in the national studies.  The third option is you can just try to discredit the numbers and make an ineffective argument that 27 months isn’t statistically significant.

The article stated he crashed into a concrete barrier in the middle of the roundabout.  As many other have pointed out in the past for similar accidents, that had nothing to do with a functionality failure of the roundabout. 

If anything, they need to figure out why drunks are flying thru roundabouts without turning.

[7/8]

I thought it was because roundabouts are too difficult for Midwesterners to negotiate (as in you don't drive over them, or stop and make a left or right hand turn, etc etc).

This reminds me that my grandad tried going "left" in a roundabout instead of going around the circle. The car in front of him had to stop, and the guy got out of his car and said "What are you doing?". My grandad said "I'm going over there!"

He now has poor vision in his left eye, so you'll be glad to hear he no longer has his licence.

[tradephoric]

The article stated he crashed into a concrete barrier in the middle of the roundabout.  As many other have pointed out in the past for similar accidents, that had nothing to do with a functionality failure of the roundabout. 

Use the same logic for someone who blows through a red light.  A driver blowing through a red light has nothing to do with the functionality failure of the traffic light.  But what is the point?  Ultimately, 3 out of 4 fatal crashes (75%) that have occurred in Carmel over a 27 month period happened at roundabouts.  This just doesn't jive with what we have all been told by the experts.

[jeffandnicole]

I missed the story where the experts told us how many fatals to expect in a 27 month period in Carmel.  Can you post that link?

[jakeroot]

Are drink/driving collisions statistically significant? I mean, we want to prevent fatal collisions; roundabouts almost certainly have a better fatality record than intersections, simply because there's little in the way of right angles. But is there really anything we can do to meaningfully prevent said collisions? Short of further development in self-driving technology.

[tradephoric]

It sounds like we want to ignore alcohol related fatalities in Carmel's roundabouts.  Fine, let's do that.  If you take out the roundabout fatalities that involved alcohol, you are still left with one fatal roundabout crash in 2014.  That means 50% of your fatalities in Carmel occurred at roundabouts over a 27 month period.  Carmel, the roundabout capital of the United States, where you are just as likely to die in a roundabout as anywhere else in the city. 

[cjw2001]

It sounds like we want to ignore alcohol related fatalities in Carmel's roundabouts.  Fine, let's do that.  If you take out the roundabout fatalities that involved alcohol, you are still left with one fatal roundabout crash in 2014.  That means 50% of your fatalities in Carmel occurred at roundabouts over a 27 month period.  Carmel, the roundabout capital of the United States, where you are just as likely to die in a roundabout as anywhere else in the city.

I live locally to the area and fear not for my safety.

And to add an interesting data point, just one hour ago I was driving through the roundabout near my house on the way home.  Because of the reduced number of conflict points I was able to pay 100% attention to the idiot driver arriving at a high rate of speed from the road to my right (I had already entered the roundabout).   I was easily able to stop and avoid the idiot who blew through the yield sign.   You will have idiot drivers with all types of intersections, from personal experience I find it far easier to avoid the idiots with a roundabout than with other types of intersections where the idiots are approaching from all directions.

Also this was a Westfield roundabout, not a Carmel roundabout.   The Carmel roundabouts tend to have much better designed approach roads to force the approaching drivers to slow.   Never the less since I was oriented with a clear view of the approaching car it was very easy for me to take action to avoid the collision.

[cjw2001]

For contrast, here is a story about a similar situation at a four way stop where the bus driver disregarded the stop sign and took out an SUV, sending the driver of the SUV to intensive care.  Likely would have been a far different result at a roundabout, where the bus driver would have had to slow somewhat and the SUV would have had a clear view of the approaching bus.