Crash prone 'modern roundabouts'

[SEWIGuy]

The fact that "ten dead" is the worst crash since the 80s is a testament to how much driver training actually occurs in Australia.

Pretty good for a "third world country."

[tradephoric]

EPPD say high speed crash killed two men, injured seven in the Upper Valley
https://kvia.com/news/top-stories/2023/06/18/2-dead-multiple-seriously-injured-in-upper-valley-crash/

2 dead and 7 injured after the driver of a Cadillac CTS hit a landscape boulder at the County Club Rd/Memory Dr. roundabout in El Paso over the weekend. 

[kphoger]

EPPD say high speed crash killed two men, injured seven in the Upper Valley
https://kvia.com/news/top-stories/2023/06/18/2-dead-multiple-seriously-injured-in-upper-valley-crash/

2 dead and 7 injured after the driver of a Cadillac CTS hit a landscape boulder at the County Club Rd/Memory Dr. roundabout in El Paso over the weekend. 

But is it crash-prone?

[tradephoric]

I asked ChatGPT if modern roundabouts should be designed with fixed objects in the central island.  By no means am i claiming this is a great answer (reasons given are almost laughable) but I ultimately agree that fixed objects inside the central island of a roundabout are not desired in most circumstances. 

No, roundabouts should not be designed with fixed objects in the central island. The design principles of roundabouts prioritize safety, efficiency, and smooth traffic flow, and introducing fixed objects in the central island goes against these principles.

Here are some reasons why roundabouts are typically designed without fixed objects in the central island:

Safety: Fixed objects obstruct the visibility of drivers and increase the risk of collisions. Roundabouts are intended to provide clear sightlines and unobstructed views, allowing drivers to see approaching traffic and make informed decisions. Fixed objects can create blind spots and hinder drivers' ability to navigate the roundabout safely.

Traffic flow: Roundabouts are designed to keep traffic moving smoothly with minimal interruptions. Fixed objects can disrupt the flow by causing drivers to slow down, maneuver unpredictably, or hesitate. This can lead to congestion and increase the potential for accidents.

Pedestrian access: Roundabouts often have designated pedestrian crossings or paths within or around them. Placing fixed objects in the central island can impede pedestrian access and make it more challenging for pedestrians to navigate safely.

Emergency vehicle access: Roundabouts are designed to accommodate emergency vehicles, which require clear and unobstructed paths to respond quickly to emergencies. Fixed objects in the central island can hinder the movement of emergency vehicles, delaying their response times.

However, it's worth noting that there may be some exceptions or variations in roundabout designs in specific locations. Local traffic authorities and transportation engineers consider various factors, including traffic volume, available space, and specific site requirements when designing roundabouts. While it's generally preferred to avoid fixed objects in the central island, there may be instances where carefully designed and placed objects are deemed acceptable.

[tradephoric]

Here's a much better response discussing the issue of fixed objects in roundabouts.  This was published on the ASCE website.

Central question

The issue of what to put or not put in the roundabout's central island is debated among traffic engineers. In the mini-roundabouts, the central island is paved precisely so that vehicles – especially large trucks – can drive across the island when necessary. But for larger roundabouts, the central island is often raised several inches or more above the grade of the road and can feature either landscaping or other objects, including sculptures, monuments, and even fountains. Such visual obstructions can "make the drivers focus on the road in front of them instead of looking across the roundabout,"  says Hu.

It can be especially useful to block the view across the central island at night, when the headlights of vehicles approaching the roundabout might give drivers on the opposite side of the circular intersection the false notion that the road continues straight, notes Brian Walsh, P.E., the state traffic design and operations engineer at the Washington State Department of Transportation and the chair of the Transportation Research Board Standing Committee on Roundabouts and Other Intersection Design and Control Strategies.

That is why his department has created design guidance to encourage raising the elevation of some central islands with hill-like mounds – parabolic shapes made from river rocks and other natural materials – to heights of 6 ft or more to block the views of the headlights on approaching vehicles. Together with reflective signage and even illumination of the central island, the approach should help nighttime drivers "realize there's something in the middle there, so they make better decisions on slowing down as they approach and deflecting or going around,"  Walsh explains. "We want them to see that there's (something) in the tangent road, that it isn't straight."  The geometry ahead of the roundabout intersection can also help drivers see the curvilinear elements of the roundabout intersection.

Other traffic engineers contend that the central island should not have fixed objects such as statues or other hard structures because drivers – admittedly, not always sober or fully in control of their vehicles – are "having very serious collisions"  with such obstacles in roundabouts, says Lalani. Instead, he recommends that there should only be "forgiving things"  in the central island, such as low bushes that can be driven over or things that can be easily knocked aside.

With respect to fixed objects within the central island, the context of the site matters, says Johnson. Fixed objects should be avoided in roundabouts located along high-speed roads – which he defines as roadways with posted speeds of 45 mph or higher. They are less of a concern along low-speed roads where "the probability of hitting the central island is much lower – and so it might be acceptable to risk putting in, for example, a statue or other fixed object"  that may be used to represent the local culture, history, or art, Johnson explains.

[kalvado]

I asked ChatGPT if modern roundabouts should be designed with fixed objects in the central island.  By no means am i claiming this is a great answer (reasons given are almost laughable) but I ultimately agree that fixed objects inside the central island of a roundabout are not desired in most circumstances. 

No, roundabouts should not be designed with fixed objects in the central island. The design principles of roundabouts prioritize safety, efficiency, and smooth traffic flow, and introducing fixed objects in the central island goes against these principles.

Here are some reasons why roundabouts are typically designed without fixed objects in the central island:

Safety: Fixed objects obstruct the visibility of drivers and increase the risk of collisions. Roundabouts are intended to provide clear sightlines and unobstructed views, allowing drivers to see approaching traffic and make informed decisions. Fixed objects can create blind spots and hinder drivers' ability to navigate the roundabout safely.

Traffic flow: Roundabouts are designed to keep traffic moving smoothly with minimal interruptions. Fixed objects can disrupt the flow by causing drivers to slow down, maneuver unpredictably, or hesitate. This can lead to congestion and increase the potential for accidents.

Pedestrian access: Roundabouts often have designated pedestrian crossings or paths within or around them. Placing fixed objects in the central island can impede pedestrian access and make it more challenging for pedestrians to navigate safely.

Emergency vehicle access: Roundabouts are designed to accommodate emergency vehicles, which require clear and unobstructed paths to respond quickly to emergencies. Fixed objects in the central island can hinder the movement of emergency vehicles, delaying their response times.

However, it's worth noting that there may be some exceptions or variations in roundabout designs in specific locations. Local traffic authorities and transportation engineers consider various factors, including traffic volume, available space, and specific site requirements when designing roundabouts. While it's generally preferred to avoid fixed objects in the central island, there may be instances where carefully designed and placed objects are deemed acceptable.

Doctor Google suggested some meds for me, but I don't trust PE ChatGPT that much....

[tradephoric]

Two accidents in two days at same roundabout in The Villages
https://www.villages-news.com/2023/05/01/two-accidents-in-two-days-at-same-roundabout-in-the-villages/

Both accidents involved drivers going through the central island and hitting a tree.

Wayne Dennis Lender, 72, of 2187 Dorst Lane, was driving a white 2023 Cadillac CTS four-door at 9 p.m. Saturday traveling east on Warm Springs Avenue when his vehicle jumped the curb, hit a tree and flipped onto its roof in the roundabout at Fenney Way, according to an accident report from the Wildwood Police Department. When emergency personnel arrived at the scene, the vehicle was in the middle of the roundabout.

The previous day, 22-year-old Kirsten Michelle Carroll of Bushnell was injured in a single-vehicle crash at the same roundabout. She was driving a silver 2017 Nissan Altima eastbound on Warm Springs Avenue at 10:46 p.m. Friday when her car crashed into a tree in the middle of the roundabout. The airbags deployed in her vehicle and she suffered a possible broken leg as well as lacerations to her face and arms, the accident report said. She was transported by ambulance to UF Health-Leesburg Hospital.

[Rothman]

Two accidents in two days at same roundabout in The Villages
https://www.villages-news.com/2023/05/01/two-accidents-in-two-days-at-same-roundabout-in-the-villages/

Both accidents involved drivers going through the central island and hitting a tree.

Wayne Dennis Lender, 72, of 2187 Dorst Lane, was driving a white 2023 Cadillac CTS four-door at 9 p.m. Saturday traveling east on Warm Springs Avenue when his vehicle jumped the curb, hit a tree and flipped onto its roof in the roundabout at Fenney Way, according to an accident report from the Wildwood Police Department. When emergency personnel arrived at the scene, the vehicle was in the middle of the roundabout.

The previous day, 22-year-old Kirsten Michelle Carroll of Bushnell was injured in a single-vehicle crash at the same roundabout. She was driving a silver 2017 Nissan Altima eastbound on Warm Springs Avenue at 10:46 p.m. Friday when her car crashed into a tree in the middle of the roundabout. The airbags deployed in her vehicle and she suffered a possible broken leg as well as lacerations to her face and arms, the accident report said. She was transported by ambulance to UF Health-Leesburg Hospital.

Pfft.  So, old people can't handle roundabouts.

[kalvado]

Two accidents in two days at same roundabout in The Villages
https://www.villages-news.com/2023/05/01/two-accidents-in-two-days-at-same-roundabout-in-the-villages/

Both accidents involved drivers going through the central island and hitting a tree.

Wayne Dennis Lender, 72, of 2187 Dorst Lane, was driving a white 2023 Cadillac CTS four-door at 9 p.m. Saturday traveling east on Warm Springs Avenue when his vehicle jumped the curb, hit a tree and flipped onto its roof in the roundabout at Fenney Way, according to an accident report from the Wildwood Police Department. When emergency personnel arrived at the scene, the vehicle was in the middle of the roundabout.

The previous day, 22-year-old Kirsten Michelle Carroll of Bushnell was injured in a single-vehicle crash at the same roundabout. She was driving a silver 2017 Nissan Altima eastbound on Warm Springs Avenue at 10:46 p.m. Friday when her car crashed into a tree in the middle of the roundabout. The airbags deployed in her vehicle and she suffered a possible broken leg as well as lacerations to her face and arms, the accident report said. She was transported by ambulance to UF Health-Leesburg Hospital.

Pfft.  So, old people can't handle roundabouts.

If you add "but we should be building them anyway", that may qualify as a hate crime in NY

[tradephoric]

Pfft.  So, old people can't handle roundabouts.

One of the drivers was a 22-year old woman.

[tradephoric]

TRAFFIC ALERT | Tanker hauling milk rolls at Walker roundabout
https://www.wzzm13.com/article/traffic/tanker-hauling-milk-rolls-at-walker-roundabout/69-139fc2d1-63d2-47b8-9f83-6468732bb443

This crash happened on June 15th, 2023.  I'm familiar with this roundabout as I took before/after footage of the roundabout.

[kphoger]

So, old people can't handle roundabouts.

I learned this when they installed roundabouts in Branson.

Especially old people from Arkansas...

[kalvado]

TRAFFIC ALERT | Tanker hauling milk rolls at Walker roundabout
https://www.wzzm13.com/article/traffic/tanker-hauling-milk-rolls-at-walker-roundabout/69-139fc2d1-63d2-47b8-9f83-6468732bb443

This crash happened on June 15th, 2023.  I'm familiar with this roundabout as I took before/after footage of the roundabout.

Call me when a truck carrying chocolate spills it. Or something else I may like. Milk isn't worth it...

[Rothman]

Pfft.  So, old people can't handle roundabouts.

One of the drivers was a 22-year old woman.

Okay, so people who aren't paying attention to where they're driving while driving can't handle roundabouts.

[tradephoric]

4 vehicles involved in serious head-on crash in Kalamazoo County roundabout
https://www.fox17online.com/news/local-news/kzoo-bc/kalamazoo/4-vehicles-involved-in-head-on-crash-in-kalamazoo-county-roundabout

Reported driver was traveling SB before being involved in a head on crash at the roundabout.  Drivers traveling SB approaching the roundabout are going up a hill which is obstructing the view of the roundabout.  It just looks like you are traveling on a straight 45 mph 4-lane road.

[Rothman]

4 vehicles involved in serious head-on crash in Kalamazoo County roundabout
https://www.fox17online.com/news/local-news/kzoo-bc/kalamazoo/4-vehicles-involved-in-head-on-crash-in-kalamazoo-county-roundabout

Reported driver was traveling SB before being involved in a head on crash at the roundabout.  Drivers traveling SB approaching the roundabout are going up a hill which is obstructing the view of the roundabout.  It just looks like you are traveling on a straight 45 mph 4-lane road.

Pfft.  Looking further on GSV, visual obstruction is not an issue here.  You also then have adequate signage.

Driver error.  Again.

[SEWIGuy]

This topic has gone from "crash prone modern roundabouts" to "crashes at roundabouts."

[kphoger]

This topic has gone from "crash prone modern roundabouts" to "crashes at roundabouts."

Exactly.

|tradephoric|:  Do you not even care if these roundabouts are crash-prone anymore?

[tradephoric]

The Sprinkle Road & I-94 roundabout is crash prone.  In 2019 it was the 5th most crash prone roundabout in Michigan with 71 crashes and 2 injuries and the most crash prone roundabout outside of SE Michigan.  In 2020 total crashes went down to 33 but injuries tripled to 6 (and was still the most crash prone roundabout in the state outside of SE Michigan).

Sprinkle Road Roundabout Makes Dubious Top Ten List
https://wkfr.com/sprinkle-road-roundabout-makes-dubious-top-ten-list/

[tradephoric]

There are more visual clues for NB drivers that a roundabout is approaching as opposed to SB drivers.

NB drivers approaching the roundabout


SB drivers approaching the roundabout

 

[kalvado]

There are more visual clues for NB drivers that a roundabout is approaching as opposed to SB drivers.

NB drivers approaching the roundabout


SB drivers approaching the roundabout

can you do everyone a favor and paste google maps link?

[kphoger]

can you do everyone a favor and paste google maps link?

https://goo.gl/maps/iVL3vJCTd3X63rRF6

I gotta say, it would be easy to miss.  Just a yellow diamond warning sign, and then the roundabout is at the crest of the hill.

[HighwayStar]

I think I identified my least favorite roundabout implementation on a recent trip.
While driving Arizona 260 and 89A to Jerome I was subjected to something like 12 roundabouts in 17 miles while driving what was obstinately a highway. Much of the route had speed limits of 55 or 45 and every mile or two I had to slow down to screech through a roundabout with some minor road that likely had a fraction of the traffic.

I'm not a roundabout fan generally, but this had to be the worst implementation I have ever seen. Breaking up a major highway where I should be able to set the cruise at 65 and just go where I am going with a dozen of these stupid things. Canceling the cruise, slow down, speed up, etc. Its irritating, definitely wastes gasoline, and seems to serve no other purpose than be cheap and trendy compared to some proper interchanges. 

[Rothman]

The Sprinkle Road & I-94 roundabout is crash prone.  In 2019 it was the 5th most crash prone roundabout in Michigan with 71 crashes and 2 injuries and the most crash prone roundabout outside of SE Michigan.  In 2020 total crashes went down to 33 but injuries tripled to 6 (and was still the most crash prone roundabout in the state outside of SE Michigan).

Wasn't the roundabout completed in 2016?  A fuller set of data would tell a better story, especially if crashes have continued to drop off.

Then again, how many times have we called you out on cherry picking data and you've just ignored us?

[tradephoric]

Wasn't the roundabout completed in 2016?  A fuller set of data would tell a better story, especially if crashes have continued to drop off.

Then again, how many times have we called you out on cherry picking data and you've just ignored us?

Every year the 18 1/2 Mile & Van Dyke roundabout in Sterling Heights shows up on the list of intersections with the most crashes in Michigan.  In 2021 there were 168 total crashes and 17 injuries.  That roundabout was completed in 2005.  After nearly two decades, drivers are still having trouble with that roundabout.  You can blame it on driver error, but as the complexity of these roundabouts increase it can become increasingly difficult for drivers to navigate safely.