Crash prone 'modern roundabouts'

[kphoger]

License does little to improve driving skills.

Considering that the driver in question improperly changed lanes, and studying for a license involves learning when it's OK to change lanes and how to safely do that, I'd say your claim is baseless.

[kalvado]

License does little to improve driving skills.

Considering that the driver in question improperly changed lanes, and studying for a license involves learning when it's OK to change lanes and how to safely do that, I'd say your claim is baseless.

I see people using roundabout lanes incorrectly at least once a week.. I would say 1 out of 20-50 drivers does that. If you include failure to signal intentions (NY term for not using turn signal) - probably 1 out of 3-5. I doubt that many drivers are unlicensed...
And in NY the only thing you really need to know to pass a test - drunk driving is bad, BAD, BAD!!! Add a pinch of common sense (like "running over police officer who signals you to stop on green light" is probably an incorrect answer) , and you easily get passing grade.

[tradephoric]

Roundabout safety on Hilliard's radar
http://www.thisweeknews.com/news/20170221/roundabout-safety-on-hilliards-radar

According to a Mid-Ohio Regional Planning Commission (MORPC) study, the top 3 most crash prone intersections in Hilliard from 2013-2015 have been at modern roundabouts.  The Cemetery Road and Main Street roundabout had the highest number of accidents in Hilliard:  233 crashes during the three-year period.  Of course maybe 233 unlicensed drivers have been driving around the streets of Hilliard wreaking havoc. 

Here's a complete list of the 5 most crash prone intersections in Hilliard according to the MORPC study:
#1.  Cemetery Road and Main Street (roundabout) — 233 crashes including 7 minor injuries
#2.  Main Street and Scioto Darby Road (roundabout) — 141 crashes including 8 minor injuries
#3.  Davidson Road and Britton Parkway (roundabout) — 72 crashes including 7 minor injuries
#4.  Cemetery Road and Lyman Drive (traffic signal) — 58 crashes (doesn't mention how many injuries)
#5.  Cemetery Road and Britton Parkway (traffic signal) — 52 crashes (doesn't mention how many injuries)

[kphoger]

I see people using roundabout lanes incorrectly at least once a week.. I would say 1 out of 20-50 drivers does that. If you include failure to signal intentions (NY term for not using turn signal) - probably 1 out of 3-5. I doubt that many drivers are unlicensed...

Your argument is basically...
1. Some people drive incorrectly.
2. Most of them have licenses.
3. Therefore, licensing doesn't help people drive correctly.

That's the same logic as...
1. Some people get injured while riding a bicycle.
2. Most of them are wearing helmets.
3. Therefore, helmets do not protect cyclists from injury.

[kalvado]

I see people using roundabout lanes incorrectly at least once a week.. I would say 1 out of 20-50 drivers does that. If you include failure to signal intentions (NY term for not using turn signal) - probably 1 out of 3-5. I doubt that many drivers are unlicensed...

Your argument is basically...
1. Some people drive incorrectly.
2. Most of them have licenses.
3. Therefore, licensing doesn't help people drive correctly.

That's the same logic as...
1. Some people get injured while riding a bicycle.
2. Most of them are wearing helmets.
3. Therefore, helmets do not protect cyclists from injury.

Well, tell me how helmets affect broken leg statistics...

License guarantees some minimum skill level for new driver. Not a very high level, I would say. Then there is experience accumulated over years - insurance companies definitely think so, and there are some legal provisions - like certain experience required to supervise learning driver.

In this case we have a 32 year who was never licensed. Do you think there was no driving experience involved? I doubt so, more like someone who never got pulled over in the past 10 years. Abruptly changing lanes in roundabout is more of a sign of someone getting confused than someone not knowing the law...

[DaBigE]

I see people using roundabout lanes incorrectly at least once a week.. I would say 1 out of 20-50 drivers does that. If you include failure to signal intentions (NY term for not using turn signal) - probably 1 out of 3-5. I doubt that many drivers are unlicensed...

Your argument is basically...
1. Some people drive incorrectly.
2. Most of them have licenses.
3. Therefore, licensing doesn't help people drive correctly.

That's the same logic as...
1. Some people get injured while riding a bicycle.
2. Most of them are wearing helmets.
3. Therefore, helmets do not protect cyclists from injury.

Well, tell me how helmets affect broken leg statistics...

License guarantees some minimum skill level for new driver. Not a very high level, I would say. Then there is experience accumulated over years - insurance companies definitely think so, and there are some legal provisions - like certain experience required to supervise learning driver.

Sounds to me like we need more drivers' license and educational reform (along with a healthy dose of personal responsibility). When did ignorance become an acceptable excuse? When has that ever worked in fighting a traffic ticket?

In this case we have a 32 year who was never licensed. Do you think there was no driving experience involved? I doubt so, more like someone who never got pulled over in the past 10 years. Abruptly changing lanes in roundabout is more of a sign of someone getting confused than someone not knowing the law...

Agree to disagree. People are becoming lazier drivers overall.  Just about any big box parking lot will give a good example on how careless and lazy people are. But, like your statement, it's based on biased observation. Lane lines, like red lights seem to have a gray area of definition until someone crashes. Just on my drive to work this morning, it was mind-blowing how many people sneak through seconds after the light has turned red.

[jakeroot]

While I have swayed my view on roundabouts many times, there is one certainty that I cannot ignore: drunk drivers and idiots will always be a thing. While designing a roadway around those types of people is obviously not of utmost important to engineers, one of the main goals of an engineer is to design a road that is safe for all drivers. That does, unfortunately, mean designing for drunks and idiots. A road that is the most forgiving will likely produce the least amount of collisions. Roundabouts are not forgiving at all. If you don't react to them, you will crash. You have to turn the steering wheel, brake, (shift if necessary) and accelerate back out of it, while simultaneously maintaining lane position and following all relevant signage. It's very easy to do if you aren't an idiot or drunk, but if you are, it's definitely not as easy as sailing through a signal.

Now, with that in mind, here's where I think roundabouts are still quite good even when idiots and drunks are involved. A drunk or inattentive driver sailing through a red light has potentially fatal consequences. At the very least, any collision (likely of the t-bone variety) could be very severe, with life-threatening injuries almost a certainty. Roundabouts, as far as I know, have far fewer severe collisions, and overall less deaths even though most double-lane roundabouts have more collisions than the intersection that they replaced.

We basically have two options here: 1) accept the fact the double lane roundabouts produce more collisions, but are safer, or 2) revert back to large signals because roundabouts cause too many collisions, despite an overall reduction in severity and fatalities. It's almost to the point where it's more a factor of which control type produces more optimal traffic flow. Both signals and roundabouts have their ups and downs; neither is better than the other, IMO.

[kalvado]

People are becoming lazier drivers overall.  Just about any big box parking lot will give a good example on how careless and lazy people are. But, like your statement, it's based on biased observation. Lane lines, like red lights seem to have a gray area of definition until someone crashes. Just on my drive to work this morning, it was mind-blowing how many people sneak through seconds after the light has turned red.

Congratulations! You just achieved OLD FART rank!

The grass much greener and drivers much better those days, right?

[tradephoric]

Reconstruction of Jacaranda roundabout to start March 6
http://www.heraldtribune.com/news/20170222/reconstruction-of-jacaranda-roundabout-to-start-march-6

The city of Venice is spending $1.1 million dollars to reconstruct a roundabout that was built in 2011.  The roundabout at Jacaranda Boulevard and Venice Avenue is the highest crash prone intersection in the region and they believe the proposed changes (which includes realigning the splitter islands, bigger yield signs, and pavement marking changes) will cut down on the number of crashes.  Of course much of the roundabout will remain two-lanes, which seems to be the real culprit when you have these high crash rate roundabouts.

[DaBigE]

While I have swayed my view on roundabouts many times, there is one certainty that I cannot ignore: drunk drivers and idiots will always be a thing. While designing a roadway around those types of people is obviously not of utmost important to engineers, one of the main goals of an engineer is to design a road that is safe for all drivers. That does, unfortunately, mean designing for drunks and idiots. A road that is the most forgiving will likely produce the least amount of collisions.

Putting the Devil's Advocate hat on...
Where do we draw the line of "idiot" drivers? Even the crash cushions in front of freeway hazards have their design limits. Is it the idiot driving drunk in a Prius going 45 mph or an idiot drunk and hitting up on heroin behind the wheel of U-haul truck going 70 mph?

[kalvado]

We basically have two options here: 1) accept the fact the double lane roundabouts produce more collisions, but are safer, or 2) revert back to large signals because roundabouts cause too many collisions, despite an overall reduction in severity and fatalities. It's almost to the point where it's more a factor of which control type produces more optimal traffic flow. Both signals and roundabouts have their ups and downs; neither is better than the other, IMO.

Well, I would add some more statements: Properly designed intersection is better than poorly designed roundabout. Properly designed roundabout is better than poorly designed intersection.
Now my problem is that I see no good understanding of what makes roundabout properly designed, and I see no desire to learn.... Light controlled intersections are in business for .. hundred years, right? - and are pretty well understood...

[DaBigE]

People are becoming lazier drivers overall.  Just about any big box parking lot will give a good example on how careless and lazy people are. But, like your statement, it's based on biased observation. Lane lines, like red lights seem to have a gray area of definition until someone crashes. Just on my drive to work this morning, it was mind-blowing how many people sneak through seconds after the light has turned red.

Congratulations! You just achieved OLD FART rank!

The grass much greener and drivers much better those days, right?

Huh, so 33 equates to 'old fart'. Gotcha. Recent statistics for crashes where distracted driving was involved seem to differ with your assertion.

[kalvado]

People are becoming lazier drivers overall.  Just about any big box parking lot will give a good example on how careless and lazy people are. But, like your statement, it's based on biased observation. Lane lines, like red lights seem to have a gray area of definition until someone crashes. Just on my drive to work this morning, it was mind-blowing how many people sneak through seconds after the light has turned red.

Congratulations! You just achieved OLD FART rank!

The grass much greener and drivers much better those days, right?

Huh, so 33 equates to 'old fart'. Gotcha. Recent statistics for crashes where distracted driving was involved seem to differ with your assertion.

Some people are born as old farts, some remain young in their heart past 100 anniversary..
Relax, distracted driving was a pet issue 2 FHWA administrators ago...

[jakeroot]

While I have swayed my view on roundabouts many times, there is one certainty that I cannot ignore: drunk drivers and idiots will always be a thing. While designing a roadway around those types of people is obviously not of utmost important to engineers, one of the main goals of an engineer is to design a road that is safe for all drivers. That does, unfortunately, mean designing for drunks and idiots. A road that is the most forgiving will likely produce the least amount of collisions.

Putting the Devil's Advocate hat on...
Where do we draw the line of "idiot" drivers? Even the crash cushions in front of freeway hazards have their design limits. Is it the idiot driving drunk in a Prius going 45 mph or an idiot drunk and hitting up on heroin behind the wheel of U-haul truck going 70 mph?

I'm not sure I could define "idiot". The point is to design a forgiving roadway. I suppose someone who crashes on a road that was designed to be forgiving would be considered an idiot.

I do have one issue with forgiving roadways. They are very easy to drive on without paying attention. Americans are very relaxed drivers (except those who aren't). We prefer automatics. We build our cities in straight lines. Signals at crossroads, etc. The second you install a road feature that requires even a modicum of quick but difficult assessment, you may end up creating collisions that weren't there before.

Compared to single lane roundabouts, which are often low speed affairs and require almost no thinking other than "give way to the left", double lane roundabouts suffer because they are often installed along high speed roadways, and they require you to assess signage and pavement markings quickly, while simultaneously not crashing into the vehicle next to you. For most of us, this is no problem. But there are some drivers out there who are so incredibly dumb, so inattentive and lacking in skill...they can't handle quick thinking and *BAM* collision.

[kalvado]

I do have one issue with forgiving roadways. They are very easy to drive on without paying attention. Americans are very relaxed drivers (except those who aren't). We prefer automatics. We build our cities in straight lines. Signals at crossroads, etc. The second you install a road feature that requires even a modicum of quick but difficult assessment, you may end up creating collisions that weren't there before.

Compared to single lane roundabouts, which are often low speed affairs and require almost no thinking other than "give way to the left", double lane roundabouts suffer because they are often installed along high speed roadways, and they require you to assess signage and pavement markings quickly, while simultaneously not crashing into the vehicle next to you. For most of us, this is no problem. But there are some drivers out there who are so incredibly dumb, so inattentive and lacking in skill...they can't handle quick thinking and *BAM* collision.

Just brought up by your words:
Once upon a time, I was reading an article on interface on MTA ticket machines, ones selling fare cards for NYC subway.
The interface is minimalistic, and if you make a mistake, you need to start all over again. Why?
Well, because majority of customers use those machines quite often, know what to do, what to expect, and don't need fancy options.
Now for roads that is commuter vs out-of-towner dilemma. The only difference is that resetting after the *BAM* is a bit more difficult...

[jeffandnicole]

I do have one issue with forgiving roadways. They are very easy to drive on without paying attention. Americans are very relaxed drivers (except those who aren't). We prefer automatics. We build our cities in straight lines. Signals at crossroads, etc. The second you install a road feature that requires even a modicum of quick but difficult assessment, you may end up creating collisions that weren't there before.

Compared to single lane roundabouts, which are often low speed affairs and require almost no thinking other than "give way to the left", double lane roundabouts suffer because they are often installed along high speed roadways, and they require you to assess signage and pavement markings quickly, while simultaneously not crashing into the vehicle next to you. For most of us, this is no problem. But there are some drivers out there who are so incredibly dumb, so inattentive and lacking in skill...they can't handle quick thinking and *BAM* collision.

Just brought up by your words:
Once upon a time, I was reading an article on interface on MTA ticket machines, ones selling fare cards for NYC subway.
The interface is minimalistic, and if you make a mistake, you need to start all over again. Why?
Well, because majority of customers use those machines quite often, know what to do, what to expect, and don't need fancy options.
Now for roads that is commuter vs out-of-towner dilemma. The only difference is that resetting after the *BAM* is a bit more difficult...

Traffic reports are the same way.  They cater to the local motorist that uses the roads every day.  If a one-time visitor is going thru the city and doesn't know the nickname, they're not worried about it.

Current, local example:  When they say 'No delays on the Delaware River Bridges', they are clearly excluding the PA/NJ Turnpike Bridge situation.  Randomly listening to the radio, they do tend to mention the Turnpike Bridge closure more often on the weekend, when motorists not in their weekday routine may need to be a little more alert about unusual situations.

[kalvado]

Traffic reports are the same way.  They cater to the local motorist that uses the roads every day.  If a one-time visitor is going thru the city and doesn't know the nickname, they're not worried about it.

Current, local example:  When they say 'No delays on the Delaware River Bridges', they are clearly excluding the PA/NJ Turnpike Bridge situation.  Randomly listening to the radio, they do tend to mention the Turnpike Bridge closure more often on the weekend, when motorists not in their weekday routine may need to be a little more alert about unusual situations.

And the question is about the price of mistake: 30 seconds reset for MTA, hour in traffic for report (and thank you so much, Waze!), and possible injury in accident..

[DaBigE]

While I have swayed my view on roundabouts many times, there is one certainty that I cannot ignore: drunk drivers and idiots will always be a thing. While designing a roadway around those types of people is obviously not of utmost important to engineers, one of the main goals of an engineer is to design a road that is safe for all drivers. That does, unfortunately, mean designing for drunks and idiots. A road that is the most forgiving will likely produce the least amount of collisions.

Putting the Devil's Advocate hat on...
Where do we draw the line of "idiot" drivers? Even the crash cushions in front of freeway hazards have their design limits. Is it the idiot driving drunk in a Prius going 45 mph or an idiot drunk and hitting up on heroin behind the wheel of U-haul truck going 70 mph?

I'm not sure I could define "idiot". The point is to design a forgiving roadway. I suppose someone who crashes on a road that was designed to be forgiving would be considered an idiot.

I do have one issue with forgiving roadways. They are very easy to drive on without paying attention. Americans are very relaxed drivers (except those who aren't). We prefer automatics. We build our cities in straight lines. Signals at crossroads, etc. The second you install a road feature that requires even a modicum of quick but difficult assessment, you may end up creating collisions that weren't there before.

Compared to single lane roundabouts, which are often low speed affairs and require almost no thinking other than "give way to the left", double lane roundabouts suffer because they are often installed along high speed roadways, and they require you to assess signage and pavement markings quickly, while simultaneously not crashing into the vehicle next to you. For most of us, this is no problem. But there are some drivers out there who are so incredibly dumb, so inattentive and lacking in skill...they can't handle quick thinking and *BAM* collision.

Semantics aside, where's the limit on forgiving roadway? As you said, and I would agree, there are dangers to forgiving roadways too. Roads that are too straight and have no intersecting traffic can lull drivers to sleep or increase the temptation to play with their electronic devices. In many cases, we're talking about potentially designing for what are illegal behaviors...further graying the definition of a forgiving roadway.

[kalvado]

Semantics aside, where's the limit on forgiving roadway? As you said, and I would agree, there are dangers to forgiving roadways too. Roads that are too straight and have no intersecting traffic can lull drivers to sleep or increase the temptation to play with their electronic devices. In many cases, we're talking about potentially designing for what are illegal behaviors...further graying the definition of a forgiving roadway.

A well-known effect: once you improve technical safety, more relaxed attitude takes most of those gains back - not all of them. We have cars much more forgiving than they were years ago - ABS, seatbelt, airbags, crash mode test (keeping survivable volume intact). Partially taken back by higher speeds...

There is an urban legend that there were less accident with those working on high-rise structures before safety harness became mandatory (look at old pictures of NYC skyscraper construction to see how it was back then) - because people relied on themselves, not on layers of safety.  Not sure how true that is, and definitely such a story wouldn't buy you any points with EHS..

[kphoger]

Roundabouts are not forgiving at all. If you don't react to them, you will crash. You have to turn the steering wheel, brake, (shift if necessary) and accelerate back out of it, while simultaneously maintaining lane position and following all relevant signage. It's very easy to do if you aren't an idiot or drunk, but if you are, it's definitely not as easy as sailing through a signal.

Almost all of those points are also true for single-lane roundabouts, yet what I think tradephoric has brought out over the course of this thread is that single-lane or hybrid single/double-lane roundabouts do better at safety.  I really do think it comes down to the number of circulating lanes.  As I had illustrated further up-thread are are non-sideswipe conflict points on a standard 2x2 roundabout.  With a single-laner, an approaching driver only has to watch for one lane of cross traffic, but with two lanes there's a lot more at play.  Now, I don't know if this is actually what has contributed to the crash rates tradephoric has illustrated, but the fact seems to be that there's something inherent in the complexity of a 2x2 that makes it more dangerous.

Now, some of this is bound to be a lack of familiarity and education in the USA compared to, say, the British isles.  With greater familiarity and education as to how a large roundabout works, it's likely that the number of these crashes would be reduced.  But there's a fine balance between designing for what should happen and what does happen.

In this case we have a 32 year who was never licensed. Do you think there was no driving experience involved? I doubt so, more like someone who never got pulled over in the past 10 years. Abruptly changing lanes in roundabout is more of a sign of someone getting confused than someone not knowing the law...

But driver's education is about more than just knowing the law.  It's about being familiar with something before you encounter it, so you know what to do when the time comes.  For example, I grew up in a small town.  In driver's ed class, we had to drive 30 miles away for freeway driving and we had to drive out of state for "city" driving–which was a town of 8000 people.  My intuition about how to use a dual left-turn lane was incorrect, and so I was taught in class what the proper thing to do is.  Then, when I moved to the Chicago area and actually encountered dual left-turn lanes, I was able to put my knowledge to use.  Similarly, this driver might have had 15 years of driving experience, but that doesn't mean he had any experience at all with multi-lane roundabouts.  Now, I highly doubt multi-lane roundabout navigation was taught in driver's ed 15 years ago, but it should be.  Licensing does matter.

[kalvado]

But driver's education is about more than just knowing the law.  It's about being familiar with something before you encounter it, so you know what to do when the time comes.  For example, I grew up in a small town.  In driver's ed class, we had to drive 30 miles away for freeway driving and we had to drive out of state for "city" driving–which was a town of 8000 people.  My intuition about how to use a dual left-turn lane was incorrect, and so I was taught in class what the proper thing to do is.  Then, when I moved to the Chicago area and actually encountered dual left-turn lanes, I was able to put my knowledge to use.  Similarly, this driver might have had 15 years of driving experience, but that doesn't mean he had any experience at all with multi-lane roundabouts.  Now, I highly doubt multi-lane roundabout navigation was taught in driver's ed 15 years ago, but it should be.  Licensing does matter.

Well, I don't think I heard much about roundabout at the time I got the license, and my first roundabout was navigated probably 10 years after getting the card. More than enough time to forget everything I read - even if it was in the manual at that time.
I don't think I ever read anything about dual-left lanes, but few spots we got around have (quite  helpful) dashed  lines painted on pavement...

Yet again - no sane person, licensed or not, would change lanes (or perform any other maneuver)  if they see it could lead to crash and injury of another driver (at least during peace time). Guy just didn't see a motorcycle - and that does happen now and then, roundabouts or not.  Had at least one close call myself - no consequences other than angry horn from the rider, lucky me.
Now, what it adds up to from my perspective:  roundabout with plenty of points requiring attention - and easy to miss small vehicle in another lane; lane curvature not helping to use side mirrors; getting in a wrong lane - meaning going to miss the turn and trying last second correction.... Easy situation for an expensive mistake. I can see myself being prone to such mistake - with many years of driving with valid license.  And yes, roundabout is a contributing factor.   Could same thing happen in regular intersection? Who knows, those intersection also have their fair share of problems...

[cjw2001]

It looks like they are using HAWK signals to meter traffic at the 136th and Keystone Parkway roundabout in Carmel.  Maybe i'm confused, but they aren't going to use traffic signals?  Here some news articles regarding the changes.

Here is a good picture of the new HAWK signal in action.  There are two sets of signals, one pictured here for eastbound traffic at the intersection where northbound ramp traffic from Keystone Parkway enters from the right.   The other set is just before the end of that same ramp.  I've driven by the area many times since these went live, but I've yet to see them in action as they only trigger when traffic has backed up.  Think these are mainly activating during the morning (and possibly the evening) rush hour.

[kalvado]

It looks like they are using HAWK signals to meter traffic at the 136th and Keystone Parkway roundabout in Carmel.  Maybe i'm confused, but they aren't going to use traffic signals?  Here some news articles regarding the changes.

Here is a good picture of the new HAWK signal in action.  There are two sets of signals, one pictured here for eastbound traffic at the intersection where northbound ramp traffic from Keystone Parkway enters from the right.   The other set is just before the end of that same ramp.  I've driven by the area many times since these went live, but I've yet to see them in action as they only trigger when traffic has backed up.  Think these are mainly activating during the morning (and possibly the evening) rush hour.

And is it just me - or there is a perfect proof that roundabouts cannot handle high traffic? Yes, they are good in case traffic numbers a low, probably few hundred VPH... But I really want to see formalized guidelines...

[jeffandnicole]

It looks like they are using HAWK signals to meter traffic at the 136th and Keystone Parkway roundabout in Carmel.  Maybe i'm confused, but they aren't going to use traffic signals?  Here some news articles regarding the changes.

Here is a good picture of the new HAWK signal in action.  There are two sets of signals, one pictured here for eastbound traffic at the intersection where northbound ramp traffic from Keystone Parkway enters from the right.   The other set is just before the end of that same ramp.  I've driven by the area many times since these went live, but I've yet to see them in action as they only trigger when traffic has backed up.  Think these are mainly activating during the morning (and possibly the evening) rush hour.

And is it just me - or there is a perfect proof that roundabouts cannot handle high traffic? Yes, they are good in case traffic numbers a low, probably few hundred VPH... But I really want to see formalized guidelines...

Hundreds if not thousands of roundabouts, and because there's a traffic volume issue at one you say they all can't handle high volumes?

[kalvado]

And is it just me - or there is a perfect proof that roundabouts cannot handle high traffic? Yes, they are good in case traffic numbers a low, probably few hundred VPH... But I really want to see formalized guidelines...

Hundreds if not thousands of roundabouts, and because there's a traffic volume issue at one you say they all can't handle high volumes?

Question is about numbers. I didn't see actual published performance datato be used as design inputs. Looks like they are not as high as people want them to be.