Crash prone 'modern roundabouts'

[jakeroot]

The roundabout certainly sealed his fate. At least there is some hope with a signal.

I mean, seriously, if you're going full-speed towards a roundabout and your brakes just fail, what do you do? Best I can assume is to drive off the road, but that's sure to be one hell of a crash too.

[kalvado]

The roundabout certainly sealed his fate. At least there is some hope with a signal.

I mean, seriously, if you're going full-speed towards a roundabout and your brakes just fail, what do you do? Best I can assume is to drive off the road, but that's sure to be one hell of a crash too.

Crash looks mechanically survivable to me. It is a major fire that made it much worse. I assume rock installations in the center punctured gas tank from below.
And then there is an option of engine braking - at least for the truck.

[tradephoric]

Of the roundabouts with multiple fatalities that i have found, there are either rocks or a retaining wall in the central island:

96th/Westfield roundabout in Carmel, IN

(3 fatalities at roundabout... all fatal crashes involved drivers striking the retaining wall in the central island)

Big Tree/South Park Ave. roundabout in Hamburg, NY

(SUV struck rocks in central island, flipped and caught fire)

Highway 95A and U.S. 50 roundabout in Silver Springs, Nevada

(both fatal crashes involved drivers striking the rocks in the central island)

[TheHighwayMan3561]

The roundabout certainly sealed his fate. At least there is some hope with a signal.

What's the difference between this and, say, coming up behind a traffic jam on the freeway and the truck behind you can't stop? The traffic in front of you "sealed your fate".

In this particular example, I think blaming the roundabout in any way is a straw man. If it happened at a red light, no one would suggest the red light was at fault.

[Scott5114]

Maybe people shouldn't drive tractor-trailers with failing brakes? Just a thought.

[kalvado]

Maybe people shouldn't drive tractor-trailers with failing brakes? Just a thought.

While we're on this... People shouldn't commit crimes, start fires or get sick. Eliminating police, firefighters and healthcare should save a lot of money, so that actual engineers may be hired by DOTs.

[Rothman]

Maybe people shouldn't drive tractor-trailers with failing brakes? Just a thought.

While we're on this... People shouldn't commit crimes, start fires or get sick. Eliminating police, firefighters and healthcare should save a lot of money, so that actual engineers may be hired by DOTs.

A great example of a non sequitur.

[kalvado]

Maybe people shouldn't drive tractor-trailers with failing brakes? Just a thought.

While we're on this... People shouldn't commit crimes, start fires or get sick. Eliminating police, firefighters and healthcare should save a lot of money, so that actual engineers may be hired by DOTs.

A great example of a non sequitur.

Just missing a totally obvious link. But looks like I still need to explain.

It is easy to say "people shouldn't ..". But shit still happens - and a lot of things are done in anticipation that shit will happen and will hit the fan. 
Seatbelts, airbags, energy absorbing hoods - just examples engineered into most modern cars. Medians, shoulders, guardrails   on the road. Emergency exits, fire extinguishers, entire 911 system, so on so on.
Any engineer who actually earned a high school diploma should be able to ask "what would happen to my design if things go wrong?" Saying "people shouldnt..." is naiive at best, and should become outright criminal for PE holder.
Whoever designed that roundabout with a crash-enhancement island, apparently, failed to ask that question. Probably same person who thinks 4 second amber is excessive on traffic lights, though. And I don't believe people who deployed such designs and failed to learn from mistakes  should be ever allowed another chance.

[tradephoric]

Someone started a youtube channel devoted to capturing the many crashes that occur at the Milwaukee Roundabout at Walker's Point.  Here is just some example of what you can expect to see on the channel:

(recut) The first car takes out a light pole, the second car takes out a police car - Crash #030
https://www.youtube.com/watch?v=ZnE61T0fQcc

Is this the second time that poor tree got ran over? - Crash #037
https://www.youtube.com/watch?v=I8w_j1lFG9U

How high did that wheel bounce? - Crash #034
https://www.youtube.com/watch?v=4wceIogDHko

It caught fire before it even landed - Crash #023
https://www.youtube.com/watch?v=00FH-OFFinA

Motorcycle comes in hot and wipes out at the roundabout. Crash #007
https://www.youtube.com/watch?v=0WF8pPZ9HBA

They fail to yield and T-Bone a minivan! Crash #011
https://www.youtube.com/watch?v=k5IPkiVToWg

[jamess]

We should have a companion thread, "Crash Prone Signalized Intersections"

We could post dozens of videos a day.

[tradephoric]

We should have a companion thread, "Crash Prone Signalized Intersections"

We could post dozens of videos a day.

Go for it!  But keep in mind the crashes i just posted took place at the same Milwaukee roundabout over the course of a few months.  You should record what you believe is the most dangerous signalized intersection in your town for a few months and post all the crazy crashes.  Then we can compare all the crash carnage that occurred at each.

[tradephoric]

At least 3 drivers lost their wheel while approaching this roundabout.  Gotta love the drivers who run off to retrieve their wheel!

https://www.youtube.com/watch?v=L1rEMYtI6Rg
https://www.youtube.com/watch?v=4wceIogDHko
https://www.youtube.com/watch?v=ZJ8ujdtc9PM

[CoreySamson]

Consider this a soliloquy about driving on a roundabout for the first* time...

I'm scared about merging onto a roundabout (haven't yet).

My second roundabout (first was the one directly south of it) I merged onto a couple months ago was extremely intimidating. I was trying to get from NB Hermann Park Drive to Montrose, but there was an immense amount of traffic going at least 25 mph (due to the oval shape of the roundabout, they didn't have to slow down as much, plus they had no obligation to stop or yield) coming from Main St NB around the roundabout, meaning I was stopped for at least a minute trying to find an opening to get onto it (the angle at which the traffic was coming at wasn't helping, either). When I was able to get into it, I was essentially forced to exit onto Main St NB, as I was in the right lane entering the roundabout and could not merge left without causing an accident due to the amount of cars and the difference between our speeds. Luckily it didn't really affect the route I planned in the long run.

Navigating that roundabout realized my fear of merging onto one. It very much ranks in my top 5 scariest moments while driving, somewhere between trying to navigate I-35 in Austin for the first time at night and almost getting sideswiped by a speeding car I didn't see on a slip lane. I don't know if it's because of Houston drivers or because of the geometry of the roundabout, but that event was scary. If I had been less conservative and tried to force my way onto Montrose, I could've caused a pretty bad accident.

(* Technically second, but the first one wasn't busy and only had two legs)

[LilianaUwU]

(* Technically second, but the first one wasn't busy and only had two legs)

A roundabout with two legs? What's the point of that?

[CoreySamson]

(* Technically second, but the first one wasn't busy and only had two legs)

A roundabout with two legs? What's the point of that?

Apparently it's relatively common. The one I'm talking about also serves a parking lot.

[Scott5114]

Consider this a soliloquy about driving on a roundabout for the first* time...

I'm scared about merging onto a roundabout (haven't yet).

My second roundabout (first was the one directly south of it) I merged onto a couple months ago was extremely intimidating. I was trying to get from NB Hermann Park Drive to Montrose, but there was an immense amount of traffic going at least 25 mph (due to the oval shape of the roundabout, they didn't have to slow down as much, plus they had no obligation to stop or yield) coming from Main St NB around the roundabout, meaning I was stopped for at least a minute trying to find an opening to get onto it (the angle at which the traffic was coming at wasn't helping, either). When I was able to get into it, I was essentially forced to exit onto Main St NB, as I was in the right lane entering the roundabout and could not merge left without causing an accident due to the amount of cars and the difference between our speeds. Luckily it didn't really affect the route I planned in the long run.

Navigating that roundabout realized my fear of merging onto one. It very much ranks in my top 5 scariest moments while driving, somewhere between trying to navigate I-35 in Austin for the first time at night and almost getting sideswiped by a speeding car I didn't see on a slip lane. I don't know if it's because of Houston drivers or because of the geometry of the roundabout, but that event was scary. If I had been less conservative and tried to force my way onto Montrose, I could've caused a pretty bad accident.

(* Technically second, but the first one wasn't busy and only had two legs)

That isn't a modern roundabout, it's a traffic circle. Roundabouts aren't controlled by stop signs, and the circulatory road doesn't have yield signs, both of which this example has.

Also, it's on you for not being in the correct lane approaching the circle. If you want to turn left, you should be in the left lane approaching a multi-lane roundabout, the same way as you would be if you were approaching any other intersection. Roundabouts aren't designed for you to change lanes inside of them.

[jakeroot]

I still maintain that there is a significant disconnect between how some drivers see roundabouts, and how engineers see roundabouts.

To an engineer, the modern roundabout is simply an intersection that has been twisted around a central island. Besides this, rules are the same: left turns from the left lane, right turns from the right lane, and so on.

But, to some drivers (very few, those who aren't familiar with roundabouts or cannot remember how they work), that doesn't seem to translate too well. To some, I still feel like roundabouts are actually seen as a one-way circle where, regardless of the total number of lanes, exiting cannot physically be done from the inside lanes, markings be-damned, and that perpetual circulation using the outside lane would be completely fine.

[mukade]

Hamilton County, Indiana has about 250 roundabouts, and the one that has had the most accidents is at Olio Road, Southeastern Parkway, and 136th St in Fishers. I love roundabouts, but I avoid this one unless I have no other option. That said, I would still rather have this as a roundabout than as a traffic light.

From my perspective as a driver is that 1) it carries a very high volume of traffic for a roundabout, 2) the traffic patterns at certain times of day cause long waits for some approaches, (much of it caused by the lack of traffic control on Olio Rd. to the south) 3) lanes rules are inconsistent and confusing. Supposedly work will be done in the next year or two to make it safer, but I believe that work will focus on pavement markings and signage improvements.

I would be interested what the opinions of the professionals are on what could be done to make this one safer.. 

Google Maps: https://www.google.com/maps/@39.9881723,-85.9194422,17.81z
Article: http://www.fisherstos.com/the-most-dangerous-roundabout-in-hamilton-county-is-in-fishers/

[bwana39]

I still maintain that there is a significant disconnect between how some drivers see roundabouts, and how engineers see roundabouts.

To an engineer, the modern roundabout is simply an intersection that has been twisted around a central island. Besides this, rules are the same: left turns from the left lane, right turns from the right lane, and so on.

But, to some drivers (very few, those who aren't familiar with roundabouts or cannot remember how they work), that doesn't seem to translate too well. To some, I still feel like roundabouts are actually seen as a one-way circle where, regardless of the total number of lanes, exiting cannot physically be done from the inside lanes, markings be-damned, and that perpetual circulation using the outside lane would be completely fine.

I honestly prefer sitting at a RED Light to doing a roundabout.

While they lessen T-bone accidents, they increase fender benders dramatically.

If you don't go through the same roundabout all the time, there is too much thinking required.

[Scott5114]

If a roundabout is more thinking than you're comfortable with doing, you need to turn in your keys, because you're not competent to drive a motor vehicle.

[LilianaUwU]

If a roundabout is more thinking than you're comfortable with doing, you need to turn in your keys, because you're not competent to drive a motor vehicle.

I mean, I don't even have a license and I can understand a roundabout. (My field of interests might be biased towards roads, though, which would explain it.)

[Tom958]

That isn't a modern roundabout, it's a traffic circle. Roundabouts aren't controlled by stop signs, and the circulatory road doesn't have yield signs, both of which this example has.

It's not a traffic circle, either. It's a regular divided boulevard with one unusually large island put there for decorative purposes. If people misperceive it as a circle, roundabout or otherwise, then maybe the left turn access to Montrose that you were trying to get to should be closed off.

Also, it's a good idea to realize that sometimes it's better to abort a questionable move such as zipping across three lanes of Main Street traffic, do what's safest, and attempt to learn something from it. CoreySamson did it eventually, but better drivers will decide to do it more promptly. As it happens, turning right on Main, easing leftward. then turning left on Bissonet to get to Montrose is only a block longer and a lot safer if there's any traffic. Probably should make that the default route from Hermann Park to Montrose. Headed the other way, maybe Bissonet to Fannin or Caroline to Hermann Park.

[jakeroot]

If a roundabout is more thinking than you're comfortable with doing, you need to turn in your keys, because you're not competent to drive a motor vehicle.

I generally agree, although signals are probably a hair easier to quickly process than a roundabout.

[Tom958]

Hamilton County, Indiana has about 250 roundabouts, and the one that has had the most accidents is at Olio Road, Southeastern Parkway, and 136th St in Fishers. I love roundabouts, but I avoid this one unless I have no other option. That said, I would still rather have this as a roundabout than as a traffic light.

From my perspective as a driver is that 1) it carries a very high volume of traffic for a roundabout, 2) the traffic patterns at certain times of day cause long waits for some approaches, (much of it caused by the lack of traffic control on Olio Rd. to the south) 3) lanes rules are inconsistent and confusing. Supposedly work will be done in the next year or two to make it safer, but I believe that work will focus on pavement markings and signage improvements.

I would be interested what the opinions of the professionals are on what could be done to make this one safer.. 

Google Maps: https://www.google.com/maps/@39.9881723,-85.9194422,17.81z
Article: http://www.fisherstos.com/the-most-dangerous-roundabout-in-hamilton-county-is-in-fishers/

I'm not a professional, but...

The biggest problem I see here is with the overlapping paths of eastbound and southbound traffic. As a counterexample, look at the part of the circle where eastbound and northbound traffic cross. There's a small, rhombus-shaped overlap zone within which... eastbound traffic has two lanes, and it can see it has two lanes because of the solid lane lines both before and after the overlap zone and the dotted chicken feet lines within it. Northbound traffic can see that it has two lanes because of the solid lines; the chicken feet are barely visible because of the angle at which they cross the field of view. The paths of northbound and eastbound traffic cross; there is no weaving. This condition occurs four times at most four-leg multilane roundabouts and thus is familiar to Hamilton Countians.

For southbound and eastbound traffic at this roundabout, though, the overlap zone is too long due to the need to accommodate 136th Street. Rather than crossing as usual, eastbound and southbound traffic are forced into a two-lane bottleneck on the circular roadway, making it impossible for both movements to have two unobstructed lanes. The designers gave the two lanes to southbound traffic and a nasty surprise to eastbound traffic.

That article is interesting and very well-written and informative. To me, it's obvious that the accident that caused that huge discussion was caused by the driver who continued around the circle in the right lane in defiance of the pavement markings. However, I think it's likely that the culprit had reason to believe that s/he was in the right due to common practice in the plentiful multilane roundabouts throughout the area.

So, how to fix it? Removing the 136th Street leg is probably necessary but not sufficient. The exit to southbound Olio Road needs to be moved outboard far enough to create the same sort of rhombus-shaped overlap zone as is found in four locations at typical four-leg roundabouts. A less-expensive alternative might be to install overhead signage that makes it abundantly clear to eastbound traffic that only the left lane leads to eastbound Southeastern Parkway. 

[Scott5114]

If a roundabout is more thinking than you're comfortable with doing, you need to turn in your keys, because you're not competent to drive a motor vehicle.

I generally agree, although signals are probably a hair easier to quickly process than a roundabout.

Oh, I'll happily concede the point, and go so far as to say that, unlike a roundabout, as long as stoplights work properly and everyone follows them, they require near-zero thought from the driver. But there are a great deal of things that a driver can be asked to do that require way more thinking than a roundabout does, most of them require faster thinking than a roundabout does, and most of them have way more catastrophic outcomes if the wrong decision is made. Timing a merge in heavy, fast traffic with no acceleration lane is far more mentally taxing than a roundabout, because you have to parse the traffic flow and make sure you're clear ahead and behind you and do it at 70 mph instead of at a dead stop like at a roundabout.

So if you don't like roundabouts because "too much thinking is required", then too much thinking is required of you to drive a car, full stop. Take the bus.