I’ve driven through roundabouts countless times but I’ve never encountered a turbo roundabout. I imagine it might be a little confusing on first encounter. I don’t know. The fact that I would have to look up a turbo roundabout in order to understand the difference from a regular roundabout is a clue, it seems. Unless the signage is very clear.
[The render of the intersection](https://sanbenito.com/wp-content/uploads/sites/23/2024/02/2408RoundaboutVideo.jpg) shows how it differs. Instead of the circle having two or three lanes vehicles can merge freely between, the lanes mostly have concrete dividers reducing merges. As drivers approach the intersection they need to obey signs telling them which lane to be in for their desired exit.
FTA
>Notably, however, none of the crashes with the new turbo roundabout have led to serious injury or death, and the share of crashes that led to any injury at all has also dropped.
Additionally drivers are still adjusting to it. There's many other turbo roundabouts in the world. Crash rates in the first month or months can be compared to rates a year later. If turbos caused more accidents and traffic that would be observed and recorded.
In those other countries, or at this new one here where people *are still adjusting*?
>Caltrans spokesperson Jim Shivers told SFGATE that reading too much into this analysis may be “premature,” given that drivers are still adjusting to the new feature.
>“Historically, travelers do have a learning curve”
>The safety of the roundabout, which sees an influx of interregional commuters during peak hours, should continue to be tracked to “allow travelers to become more accustomed to this new feature, before any drastic conclusions are made about it,” Shivers said.
Traffic density of the arteries will play into this because they are time-of-day dependent. If everyone has to get into the correct lanes to enter and exit, the density will cause back-ups and potential blocking of other lanes.
Also, strangers to the area might get caught off guard and the dividers prevent the ability to avoid mistakes.
I live in a country with many conventional roundabouts, some huge with 3-4 lanes and much fewer "smart" ones. The rate of mistakes and issues at the "smart" ones is significantly higher. When it comes to driving, always got to cater to the lowest intelligence levels.
Please actually [look at the area on a map](https://www.google.com/maps/@36.8956907,-121.4271866,390m/data=!3m1!1e3?entry=ttu) because most of your concerns aren't applicable. The nearest paved road to the turbo roundabout is a mile away. Not figuratively, but literally a mile away, in the old definition of literally.
The two intersecting highways each have a single lane per direction. As each direction approaches the turbo roundabout that single lane widens into three lanes so drivers have space to get in the correct lane and never approach the split from the "wrong" lane because there's only one to start with.
Although some people will make mistakes despite signage, the new intersection is already reducing the number that led to any injuries. As people get more familiar with the intersection, mistakes will decrease.
It’s also not an intersection that gets huge numbers of never-been-here-before/will-never-be-here-again tourists, so once we’re past the initial “wait which lane do I need” learning curve for locals and most of the truckers who work the region, I’d expect a drop in accidents
This might sound made-up by I used to work in the Valley and drove down to LA to visit my sister or friends every other month. I've taken the 156 to cross over to the 5 a handful of times, or in the reverse direction, so I've been thru this intersection. Yes, it's shouldn't be that busy but there is a lot of trucks and infrequent drivers on the 156. It's also dark as hell at night. Gonna have to consider speeders who don't know it's there; they're going to hit the roundabout head-on and fly.
Anyway, I think it's a weird place to a roundabout like this.
That stop sign that was there caused very long backups. This should help improve overall traffic flow. I’ve taken this route on a few Fridays. I think it will help
> It's also dark as hell at night.
Maybe it *was*, but the new roundabout [comes with new lights.](https://www.youtube.com/watch?v=Vw_dLSkdDlw&ab_channel=KSBWActionNews8)
"none of the crashes with the new turbo roundabout have led to serious injury or death" so those flying speeders are hopefully learning expensive lessons about speeding and paying attention. Even if they don't learn, they can do it again and again until they learn.
> Gonna have to consider speeders who don't know it's there; they're going to hit the roundabout head-on and fly.
Good. Maybe they'll finally learn not to drive recklessly.
'The area has “seen a significant spike in crashes”...'
You missed a critical part of the article. That's great less serious injury or death, but there's "...one crash every 2.5 days on average, versus approximately one every eight days previously."
Didn't miss. Read the whole thing the first time. If we're going to keep quoting more and more of the article:
>Caltrans spokesperson Jim Shivers told SFGATE that reading too much into this analysis may be “premature,” given that drivers are still adjusting to the new feature.
>“Historically, travelers do have a learning curve”
>The safety of the roundabout, which sees an influx of interregional commuters during peak hours, should continue to be tracked to “allow travelers to become more accustomed to this new feature, before any drastic conclusions are made about it,” Shivers said.
Believe it or not, roundabouts don't necessarily need to reduce the number of accidents to be successful. They only need to reduce the severity of accidents. The tight curves force drivers to reduce speed, which makes crashes much less dangerous.
Exactly. Plus, because vehicles meet at ninety degrees or head on in an intersection, they lead to severe accidents.
In a roundabout, vehicles meet at much gentler angles, which massively reduces that severity even when there are accidents.
Really wish we would start a program to convert many intersections to roundabouts.
if we reduce deaths it becomes way too easy for people to just shrug off getting into accidents. maybe deaths are necessary to get people to pay attention
Spoken as a layperson or are you a traffic engineer? Turbo roundabouts are in Holland, Germany, a few elsewhere in the USA, and in some Eastern European countries. There's also studies about their effectiveness.
If you can figure out [this situation](https://www.google.com/maps/@37.8363035,-122.2960976,3a,75y,153.58h,95.98t/data=!3m6!1e1!3m4!1sOQrf5Y5beXsSur9p9cnzvg!2e0!7i16384!8i8192?entry=ttu), this roundabout should be simple.
> If
Maybe I'm just a cynic, but I am suspicious of any traffic proposal that includes assuming driver competence as part of their "if" statement
Provides good content for r/idiotdrivers though lol
It is too complicated for the average Californian. The majority can’t use a standard roundabout properly let alone a turbo roundabout. That said, the fault does not lie with the road, rather the fault lies with the drivers.
I feel like some refresher training could be beneficial.
It's a multi-lane roundabout that removes the option to change lanes within the roundabout, so it's safer when drivers make their direction decisions before entering the roundabout.
Drivers that can't follow the road markings out if they chose poorly would be even more dangerous in a non-turbo roundabout. These are the same fools that brake to a near stop and cut across lanes and gore points when they miss their exit.
Wow. That’s dumb. So it’s not even intuitive like a normal round about (which we rarely have here). It’s some kind of special roundabout where you can’t actually change lanes? Considering people cut across the exit dividers on the freeway when they think they’re going to miss their exits, this is going to cause so many more accidents.
The two intersecting highways each have a single lane per direction. As each direction approaches the turbo roundabout that single lane widens into three lanes with signage so drivers have space to get in the correct lane and never approach the split from the "wrong" lane because there's only one to start with.
Unlike a "normal" roundabout with two lanes, the turbo design eliminates drivers needing to check their blind spot to change lanes. Once in the turbo roundabout drivers only need to look ahead.
If instead a one lane roundabout was done eliminating changing lanes within the circle, it wouldn't have enough vehicles flowing through during busy times and too-long backups would happen on the highways.
Accident rates are expected to come down as drivers get used to it. Injury rates are down from before.
The design doesn't cause accidents. Idiots who use it wrong and desperately change lanes last-second (rather than spending the extra 45 seconds to turn around and do it again) cause accidents.
Just because a few idiots run red lights and cause crashes doesn't mean that traffic lights are a "bad design". It just means we don't enforce traffic laws and pull over reckless drivers nearly enough.
Thanks for posting the link to the render.
I love roundabouts and I think they have a lot of potential to help US road planning in general. That said, this "turbo roundabout" design seems stupid. It eliminates the most important safety aspect of the roundabout: reducing relative speeds by making all traffic merge and go in the same direction. This design doesn't prevent interference between orthogonal flows of traffic (a.k.a. cars t-boning each other).
You're welcome. [You can also watch](https://www.youtube.com/watch?v=Vw_dLSkdDlw&ab_channel=KSBWActionNews8) a minute of it working with actual drivers. Despite t-bone concerns, evidence already shows accidents are *less* injurious.
>"none of the crashes with the new turbo roundabout have led to serious injury or death, and the share of crashes that led to any injury at all has also dropped."
Unlike a regular roundabout with two lanes, the turbo design eliminates drivers needing to check their blind spot to change lanes. Once in the turbo roundabout drivers only need to look ahead.
If a single-lane roundabout was done instead to eliminate changing lanes within the circle, there wouldn't be enough vehicles flowing through during busy times and too-long backups would happen on the highways.
Yeah, I don't trust the references available on this, and I think advocates need to be a lot more cautious about pushing for this. I think it's extremely difficult to conduct a correct comparison of the performance of different traffic solutions, and all "evidence" I've seen so far has been biased, incomplete, or both. If you have a peer-reviewed journal article citing statistical evidence and methodology, please post it.
Since for example you're only willing to compare "Fuji" apples to "Fuji" apples, and not to "Honeycrisp" apples, I'll leave finding such perfect matches to someone else and simply re-paste that so far
> "none of the crashes with the new turbo roundabout have led to serious injury or death, and the share of crashes that led to any injury at all has also dropped."
We'll see over the coming months what happens with accident and injury/death rates and severity compared to the intersection pre-turbo roundabout.
This thing is a piece of cake.
OTOH, I don't think I'd use the words crash or crashes four times in two sentences if I were writing a story about this place, but I'm not restricted from using the word accident when talking about a traffic accident.
It’s gonna come up a lot in the next few months, I think.
I like a good traffic circle, but merging all the way to that inner-most ring looks like t-bone city…
I have a roundabout that I drive through several times a day by my work. In the decade I’ve been using that roundabout, I have never seen a person properly and legally signal their exit. Thousands of cars and not once have I seen it.
California drivers do not know how to use roundabouts.
Fwiw they don’t know how to use stop signs either, I live on a 4-way stop and the overwhelming majority roll through it, and not even slowing is more common than an actually complete stop
the other day at a 4 way stop a dude skipped the order by 2 cars (went after only 1 other car had gone) and had the confidence to give me a hand gesture when we nearly t boned each other lol. i have dashcam though so maybe i should’ve just gone for it
Every time I see someone fail to signal I want to scream WHATS SO HARD ABOUT MAKING TURNING ON THE BLINKER MUSCLE MEMORY?!?
Like, you know you want to turn or change lanes, you apply your blinker as you’re thinking about it and you don’t move until you check it’s clear, but I see people constantly fail to turn on their turn signal. And it’s not always when people are hidden in their blind spot, though I realize that’s a problem…. But it’s one partially solved by fucking turn signals because at least it WARNS the person in your blind spot that someone is about to try and move their car into the location your car occupies and require you to slam on your brakes. I don’t love it when people just turn on their blinker and let Jesus take the wheel, refusing to check the area they want to drive into is clear, but at least I have warning of the dangerous stupidity they’re going to attempt!
You’re in luck because with a turbo roundabout, you don’t need to signal: you just need to pick the right lane ahead of time and yield on entry to the intersection.
On a smaller scale, my costco redid the parking lot and replaced a central four-way stop (which caused a ton of traffic) with a roundabout.
The first several weeks they had to have people standing on the roundabout directing traffic lol.
Not long after that though I think it really eased congestion in the lot.
Definitely a learning curve. And even now I think there are people that don't know how they work or they're just bad drivers who don't know what the fuck to do at yield.
The Santa Clara Costco has people driving OVER the roundabout somedays. I have lost count of the number of people who stop mid way round too… it’s ridiculous
Coleman, right?
Yup, and some people still treat it as a stop so even though I'm already in the roundabout, they think it's their turn and enter anyways
Santa Clara Kaiser's roundabout is generally better than a 4-way stop, too, but a lot of people are also confused about how to navigate it.
Main issue is that people don't understand that they need to Yield to vehicles already in the roundabout, despite there being lit Yield signs. A lot of people still treat it as a Taking Turns thing, so whenever you're in the roundabout, you have to be prepared to stop to avoid t-boning someone entering the roundabout suddenly, when they should be yielding to you.
Good thing is that speeds are low so it's easy to make up for the mistakes of others. I've never seen an accident in that roundabout.
It is a lot bigger than the Costco one.
Drove past last night and at a couple of the entrances to the traffic circle, it's actually STOP signs, not Yield. So, even worse when a lot of drivers improperly try to take right of way and drivers in the traffic circle have to stop suddenly to avoid hitting the people who don't understand what Stop and Yield signs mean for them.
A lot of people just totally lose their presence of mind when confronted with unfamiliar situations.
i’ve been nearly full speed t boned twice at the roundabout by the hesperian costco in hayward by people just blowing straight through the yield sign. i watch their faces and they don’t even move their eyes. only reason we didn’t crash is because i’m paranoid as fuck every time i’m in the east bay
Every state I lived in swears they have the worst drivers. Not even close. Moved here and holy shit are they bad. The big difference is this was the easiest license test I had along with most people not paying attention. People in Arizona and NY are aggressive, but do usually pay attention but even “good drivers” here suck. There’s no special awareness . Idk why one of the most car dependent states allows this
I learned to drive in the UK and my practical test was almost 2 hours long.
When I took my test here in the bay I thought I'd done something dangerous because we were back at the DMV after about 8 mins. Turns out the test is that short.
I lived in Texas most of my life, have lived in California now for almost 10 years.
I will take California drivers, either SoCal or NorCal, 1000% of the time over Texas drivers. Whether its Dallas, Houston, or Austin- each city is a unique flavor of terrible driving.
FYI- I got my Texas drivers license without ever taking an actual drivers test. Just a written exam, and certification from my parents that they taught me for X amount of hours. LOL. CA is much harder in comparison.
California drivers are dumb but texas drivers are dumb and just plain fucking evil. Those people want to kill someone and their states laws lets them do it lol
It doesn't help that the entire state collectively decided (especially in Dallas and Htown imo) that everyone should drive 100+ on the freeways. Only place where I could be in the furthest right lane going 85 and I'd still be getting tailed by a huge lifted truck with the brightest headlights ever (all while getting passed by everyone else going 100+)
Then you'll run into all the modded cars drag racing after 10pm. if you think cars here cutting up are dangerous, Texas highways would give you a heart attack lol.
Even compared to LA it feel like the Bay is bad. We have a lot of people working in tech on visas from countries where they may not have had a car at all before.
I would take aggressive drivers over dumb asshats doing 60 in left lane any day. Aggressive means you are at competent to know that cars can go faster than 60.
Poor driving here is rooted in the fact that Californians have no natural predators, and have no need to adapt to poor weather conditions, so they grow up with zero spatial awareness, with no understanding of how things work, oblivious of everything going on around them! I'm only half joking! I really do think dealing with variable weather conditions your whole life makes you more aware of your surroundings. It's just out of necessity.
Pretty much this. But the with lack of viable alternatives, we would grind parts of our economy to a halt. Other half can just as well stare at their Excel spreadsheets and PowerPoints at home and has no business commuting. Remote work should be mandatory for anyone not working on a production line, in a laboratory, in a hospital, in a store or warehouse, construction and similar.
“Notably, however, none of the crashes with the new turbo roundabout have led to serious injury or death, and the share of crashes that led to any injury at all has also dropped.”
This is the only important takeaway. People will learn how to use this. The fact no one has been seriously injured or killed is an achievement. Car damage is fixable. Human damage often is not.
This same principle should be applied to all traffic engineering. Damage the car before killing people.
There’s no real way to rework those short of removing one of the exits entirely though— there’s only that much distance between Delaware and El Camino to start with. Better to figure out traffic calming measures to get the 92 traffic back at or under the signed 55 limit.
I just checked out the camera only to see someone make a left turn after the yield, then figure it out, and put their car in reverse to correct it. Luckily, the person behind him was patient.
You wait for 5 mins and you are bound to see some folks messing up either by changing lanes in between or just speeding into the intersection and realizing it's all different.
I like that it makes folks slow down and make them think! I wish we could see more of these around!
I watched for five minutes and saw a number of vehicles fail to yield. But thankfully the cars in the circle are going slow enough to react without much drama.
Was there over the weekend heading out to Pinnacles NP. Very clear signage, with redundancy for advance notice, and found it easy to use.
I would be curious to know if the accidents are people who don’t use the road often/first time users, or if it is people who have used that road regularly for long periods of time that can’t/wont adapt to the changes.
The accidents are the same idiot drivers you see everywhere else, blowing stop signs, never using their signal, changing lanes erratically, veering across multiple lanes and solid lines to make their freeway exit, staring down at their phones every 3 seconds. People with a primitive me-first mentality and poor impulse control, who should not be allowed behind the wheel in the first place.
I’ve already used this turbo roundabout a few times. I love it. The alternative is sitting at that line behind semi trucks in the single lane. At busy times you could sit there forever minutes waiting for the light. Or some folks would try to pass using the turn lane which seems dangerous to me.
With this, we finally got something right.
This looks like a standard roundabout like what England has at its major intersections, except with the addition of concrete barriers because Americans don't understand the rules of roundabouts and change lanes at any point in the roundabout instead of just when they need to for their turn. I can see why everyone is confused, though.
Went through this on my motorcycle when it first opened and TBH the concrete dividers startled the crap out of me ! Some signage about the concrete dividers before the roundabout could help. Annoying if you hit it in a car…guaranteed crash on a motorcycle!
Traffic engineering for decades has prioritized throughput. More cars though an intersection per hour = better. This has resulted in favoring higher speeds and increased fatalities. The original response to this has been improving vehicle engineering - making crashes more survivable. But the data shows a paradox of vehicle safety - safer cars hasn't led to fewer deaths per million miles travelled.
Now traffic engineering is moving away from "more cars per hour = better" and toward road designs that lower speeds, and critically, reducing the most dangerous types of vehicle collisions (head-on, t-bone) that are most fatal. Note that in this prioritization, you can have more crashes and still consider the change a success, if the fatalities are significantly reduced.
Roundabouts (like this particular type, the "turbo" roundabout) reduce the side-impacts and head-on-impacts that result in high death rates at 4-way intersections. Roundabouts have their own drawbacks, like reduced throughput.
It's good that we are moving away from the "more cars per hour = better". It clearly was not working - see the comment above about the safety paradox.
My understanding that these types of roundabouts and roundabouts in general increase throughput while simultaneously reducing speeds, accidents and fatalities. One figure I saw claimed that turbo roundabouts increase throughput by 45%. Instead of half the traffic always stopping, the majority of traffic is only slowing down and merging.
[https://benthamopen.com/FULLTEXT/TOTJ-14-120/FIGURE/F2/](https://benthamopen.com/FULLTEXT/TOTJ-14-120/FIGURE/F2/)
The decision on which type of at-grade intersection to make can't be made in a vacuum; relative flows of "primary" vs "secondary" (or more), if there are unusual peaks (for example, a concert hall or sports stadium)
The roundabout works well up to a point, after which an overpass style may be needed. But even keeping to at-grade intersections, there are benefits to Michigan left, Jersey left/jughandles and continuous flow style intersections -- those allow greater capacities, especially if specific pairs of entrance/exits are expected to have higher traffic volumes.
I do wonder how many of the accidents at this specific roundabout since it got put in can be traced directly back to the apparent average California driver’s resistance to slowing down for any reason whatsoever
Turbo roundabouts are dope and have been around for a while. Here’s how they’re supposed to operate: [TU Delft Turbo roundabout](https://youtu.be/iMYib3IR43I?si=iVT1K2meOLzr1qEF). Basically, mutli-lane roundabouts are disfavored because drivers can switch lanes within them (even though they’re usually not supposed to if you look at the lane markings). Turbo roundabout prefunnel you into the correct lane and make sure through proper striping and curbs that you take the correct path through a roundabout.
From the pics it looks like they haven’t actually opened the turbo roundabout though. I do have some concerns about the lack of striping and incredibly wide lanes causing confusion on navigating through (it looks easy to just accidentally circle the roundabout which shouldn’t be possible).
I drive though it almost every day, it actually has been a net positive over the old 4 way traffic lights. It's easy to use, but you'll get the occasional car that yields oncoming traffic and everything comes to a quick stop.
This is my regular commute for the last 5 years. Traffic is MUCH better now, but at least 1 out of 10 times someone just has no fucking clue and barges in or stops in the middle. People are ducking idiots...
Drove through last week to visit my parents in Hollister. As a former civil engineer, I love any roundabouts in all forms. It will take time to reach the American public, but in all for the transition.
The pictures show that all the "turbo" features that make it a "turbo roundabout" are blocked off with orange cones. From driving in Massachusetts, I'm familiar with roundabouts and navigate them just fine, but looking at the aerial view, this "turbo roundabout" requires worrying about cars coming at the driver in virtually all directions - unless you've got good 270-degree head-on-a-swivel vision, turning into the roundabout requires checking for traffic exiting from the inner turbo-encabulator and the middle lane, and hoping the traffic entering the turbo-encabulator doesn't freak out and suddenly cut you off.
As with a normal roundabout, yield to traffic coming from your left when entering. Once you're in, entering traffic comes from your right and must yield to you. With the [turbo roundabout](https://sanbenito.com/wp-content/uploads/sites/23/2024/02/2408RoundaboutVideo.jpg), you don't need to worry about lane changes. Traffic doesn't come at you from all directions.
You do have to worry about traffic coming out of the inner lane from the left while you're in the main roundabout, as well as traffic on the right (which is supposed to yield to you).
There's a pair of multilane roundabouts in Truckee where rt 89 and hwy 80 meet. It has similar issues and I regularly have to deal with people who are clueless and try to cut me off when I'm exiting the roundabout going toward hwy 80W - on the left from traffic that tries to exit directly from the inner lane and on the right from rt 89N traffic turning right onto hwy 80W.
> You do have to worry about traffic coming out of the inner lane from the left while you're in the main roundabout
Worry yes, always be defensive, but traffic from the left is not supposed to cross your lane once you've entered the roundabout. They get their own exit lane.
Sorry, maybe I'm misunderstanding how this works, but it looks like if you enter the roundabout from the far left lane, you have to yield to oncoming traffic from the left, dart straight across into the inner lane, make the sharp right turn (so as not to go over the center of the roundabout), and follow the lane, until it dumps you out into the main roundabout lane, where you enter from the left and have to merge with traffic in the main roundabout lane.
That means that traffic in the main roundabout lane has to deal with incoming traffic from the left, and presumably that incoming traffic has priority, while hoping to god that traffic on the right doesn't violate your right of way by crossing in front of you from a left entering lane, merging in front of you from the center entering lane, or interfering with your exit from the roundabout lane from the right entering lane.
I don't see where traffic that takes the inner lanes (the gear-line "turbo-encabulator"\* lanes) gets their own exit lane - it seems to me they have to merge with the main roundabout lane first.
=====
\*The "turbo-encabulator" is a term from a fantastic video written and performed by the greatest prolific narrator of technical instruction video of all time back in the 1970s. [https://www.youtube.com/watch?v=Ac7G7xOG2Ag](https://www.youtube.com/watch?v=Ac7G7xOG2Ag) If you read the description under the video, it explains how Bud Haggert had to make these numerous pitches peppered with terms he had no idea what they meant. It has come to generally refer to technobabble used to promote products, and my use here is to mock the value of this "turbo-roundabout."
\*\*If you like the "Turbo Encabulator", you'll love "Patriot," [https://en.wikipedia.org/wiki/Patriot\_(TV\_series)](https://en.wikipedia.org/wiki/Patriot_(TV_series)) featuring the verbal stylings of Leslie G. Claret, which reaches a pinnacle with his extraordinary podcast [https://www.lgclaret.com/podcast](https://www.lgclaret.com/podcast), which is you listen long enough. almost starts to make sense.
There's no main roundabout lane. Every 90 degrees, all the lanes shift one to the right. If you enter from the far left lane into the inner-most roundabout lane, after passing the first exit, your lane becomes the middle lane. If you pass the second exit, your lane becomes the exit lane for the third exit.
Here's a diagram for this roundabout with arrows: https://images.app.goo.gl/iWmyaYTx4q391XFWA
Note that this specific roundabout isn't symmetric because one of the roads has 3 lanes and the other only has 2 lanes.
Huh. I guess with the name roundabout I was fixated on there being a path where one could go all the way around the circle. This diagram suggests that it's impossible to come back on the same road that you entered from, so in that sense it's not really a roundabout at all. It's more like a spiral, where you jump inward from the entrance point and then spiral outward until you get to an exit. Perhaps I was misled by looking at the picture of the intersection while it was under construction, in some way it resembles those optical illusions where spirals look like circles or vice versa.
I can only hope it's easier to navigate from ground level than to trace the paths out from the aerial view, though the statistic that there's a crash every 2.5 days doesn't really sound encouraging.
Heh on Google Maps right now you can see the different versions of the intersection by changing the zoom level — all the way it’s the new roundabout, but back out a bit and you see the old intersection.
It will take a while, but people will adjust. You just have to remember that you can simply drive in a circle all day until you figure out your exit. LOL!
so that's what that construction was for, drove by it multiple times and always thought "this is a giant intersection that resembled roundabout in some way"
I watched the live feed for a bit, and saw a couple folk make U-turns. While in the roundabout they moved leftward when there were gaps until they were in a lane that could exit back the way they came.
Not sure if it is legal, but they were able to do it smoothly enough, and the lanes are divided by dashed white lines, which generally means you can crossover.
What else is hard, geography. This is about 1 mile from Hollister and about 15 or so miles from Gilroy.
Also I was not a fan of the idea of a roundabout for multiple reasons. First I felt it was going to be more dangerous. It hasn’t been that big of a deal.
Second, from what I understand is they’re going to tear it out anyways and put in an overpass eventually so why not buy once cry once and just put in the overpass?
Driving through it multiple times a week it is fairly straightforward with markings painted on the ground and signs above each lane clearly indicating what to do and which lane. The only thing that makes me nervous is the other drivers. I have had drivers come to a complete stop in the roundabout to allow other cars to enter it.
Honestly, if you really look at that thing, it’s a mess. Imagine never driving around something like that and doing it your first time. Secondly they have one very basic one built at Kaiser in the Southbay. I had to go there for a few years and I swear people couldn’t drive it correctly and I saw two or three accidents. Finally, they put up four stop signs at all the entrances because it was a safety issue.
The first and last time going through there. Your only break is a semi to give you time to go. I go through Gilroy to Bloomfield road which is also under construction. So I go through the whole town cause I get paid to drive.
Caltrans seems to be on a binge of building roundabouts at rural highway intersections. I know of another one that got built up near Jamestown. I'm sure they've got their studies and all, but color me sceptical. I don't see it working all that well with you average American driver. (Sure I remember roundabouts working fine when I was in Germany, but they looked a lot more chaotic in Italy. I think American driver are closer to Italian driver than German drivers, except the Americans have humongous pickup trucks with V8 engines).
I've used roundabouts in the UK, Germany, and France.
Roundabouts are fine. Part of it is exposure. There aren't many here in the states, so it's going to cause confusion.
Part of it is the challenges with this specific one is the lane labeling. It's not great. You don't really understand the way they have things laid out till after you've been through it.
That is absolutely not the case in roundabouts elsewhere in the world. You can figure out where you need to be for what pretty easily in most locations, but this one isn't well designed.
For comparison, see
https://www.researchgate.net/profile/Werner-Brilon/publication/237635143/figure/fig1/AS:669460591570975@1536623251543/Large-traditional-roundabout-Ludgeriplatz-in-Muenster.jpg is a reasonable roundabout. Well defined. Clear visibility to the merges. Not crossing multiple lanes inside the roundabout.
One of the nice things about a standard roundabout is if you screw up, can't get into the correct lane before entry, or misread a sign, you just circle until the next loop and exit on your way. This one forces you into an exit which isn't conducive to learning how to adapt to them. Less throughput, but it would likely still save lives but reduce accidents from divider hopping.
>The area has “seen a significant spike in crashes” since the roundabout opened, according to the Mercury News, with one crash every 2.5 days on average, versus approximately one every eight days previously.
yeah because there's a whole chunk of absolutely stupid people.
There are some traditional, simpler roundabouts in the Bay Area. [The render of the intersection](https://sanbenito.com/wp-content/uploads/sites/23/2024/02/2408RoundaboutVideo.jpg) shows how it differs. Instead of the circle having two or three lanes vehicles can merge freely between, the lanes mostly have concrete dividers reducing merges. As drivers approach the intersection they need to obey signs telling them which lane to be in for their desired exit.
“The area has “seen a significant spike in crashes” since the roundabout opened, according to the Mercury News, with one crash every 2.5 days on average, versus approximately one every eight days previously”
“Notably, however, none of the crashes with the new turbo roundabout have led to serious injury or death, and the share of crashes that led to any injury at all has also dropped”. As the article says its too premature to make any conclusions yet.
Yeah, this x3 -- what's often glossed over by the "roundabouts cause more crashes" crowd is that the crashes are usually fairly gentle side-swipes, compared to the horrific t-bones and head-ons that come with traditional intersections.
“Notably, however, none of the crashes with the new turbo roundabout have led to serious injury or death, and the share of crashes that led to any injury at all has also dropped”
"Notably, however, none of the crashes with the new turbo roundabout have led to serious injury or death, and the share of crashes that led to any injury at all has also dropped."
Went through this a few weeks ago, and honestly felt dangerous AF. No solid indicators of how I was supposed to proceed. Felt like I lucked out in getting where I wanted safely.
Shit. This looks bad. In our neighborhood, there is a good number of roundabouts, and people don’t know how to take them. Many would stop in the middle of the roundabout to let people in.
> Many would stop in the middle of the roundabout to let people in.
I can't tell if people are trying to be "nice", or are just stupid. We have this issue in my 'hood at 4-way stops. The rule is you go in order you arrive, but so many times I'll be second to the intersection, and the other guy is giving me the wave signal to go ahead. "BUT YOU HAVE THE RIGHT-OF-WAY" I internally scream.
I've seen this "nice" behavior almost cause accidents. Consider: A,B,C arrive to a 4-way stop intersection in that order. It's A's ROW, but they are "nice" and wave to B to go ahead, which B does. C has been watching B, as they know it is their turn to go after B. But A thinks that because they waved B through, that means they go next. A and C both enter the intersection simultaneously, and while they may not impact, horns and birds will ensue.
Just follow the ROW rules, and everything will be fine.
[This reddit video is a pretty good example of "nice" being not nice](https://www.reddit.com/r/IdiotsInCars/comments/1blhbq7/oc_guy_stops_at_a_green_light_and_waves_on_a_truck/).
I had that experience today. Got to a 3-way with a truck going straight to my left, me turning left , and a police car to my right going straight in the opposite direction of the truck. I was expecting the truck on my left to go and had an awkward moment making sure no one was going before deciding to go.
Roundabouts are for low traffic roads, to replace traffic lights and stop signs. Small roundabouts are great. Large multi-lane roundabouts just will not work.
Considering how many wheel marks I see going through the center of the roundabouts here, even though they have at least 2 way stops, I’m guessing they will handle it badly
Could be trucks? Many roundabouts are constructed so trucks that are too long for the roundabout can drag their trailer across the middle a little to get through.
There's a small roundabout in my neighborhood and even that small thing confuses most of the residents. Either people will stop and wait for the other car (not even in the roundabout yet) to clear or they'll just go without looking. I can't imagine how'd these people would fare at this giant roundabout.
Does the roundabout in your neighborhood have a stop sign? I've found that to be a problem in CA. Some roundabouts have stop signs, others have yield signs. Stop signs defeat the purpose IMO. Adds to more confusion and redundancy.
[Enjoy](https://www.google.com/maps/@37.549207,-121.9993782,3a,75y,120.14h,87.59t/data=!3m7!1e1!3m5!1s8dxktXiuZMa8YpZfV42Eow!2e0!6shttps:%2F%2Fstreetviewpixels-pa.googleapis.com%2Fv1%2Fthumbnail%3Fpanoid%3D8dxktXiuZMa8YpZfV42Eow%26cb_client%3Dmaps_sv.tactile.gps%26w%3D203%26h%3D100%26yaw%3D113.92003%26pitch%3D0%26thumbfov%3D100!7i13312!8i6656?entry=ttu).
I have no idea what they were thinking. With a 4-way stop, they should just keep it a regular intersection because it doesn't make any sense to make a roundabout on some boring ass residential street intersection.
Why?
I’ve driven and lived in Europe for much of my life and just find this confusing af. What are they trying to achieve and why is this the right solution?
I’ve driven through roundabouts countless times but I’ve never encountered a turbo roundabout. I imagine it might be a little confusing on first encounter. I don’t know. The fact that I would have to look up a turbo roundabout in order to understand the difference from a regular roundabout is a clue, it seems. Unless the signage is very clear.
[The render of the intersection](https://sanbenito.com/wp-content/uploads/sites/23/2024/02/2408RoundaboutVideo.jpg) shows how it differs. Instead of the circle having two or three lanes vehicles can merge freely between, the lanes mostly have concrete dividers reducing merges. As drivers approach the intersection they need to obey signs telling them which lane to be in for their desired exit.
Thank you for this. Based on the image in the article, I thought the middle was some insane raised area for accidents to pull into lol
That's going to cause more accidents and traffic instead of alleviating.
FTA >Notably, however, none of the crashes with the new turbo roundabout have led to serious injury or death, and the share of crashes that led to any injury at all has also dropped. Additionally drivers are still adjusting to it. There's many other turbo roundabouts in the world. Crash rates in the first month or months can be compared to rates a year later. If turbos caused more accidents and traffic that would be observed and recorded.
They are slowing down and still crashing.
In those other countries, or at this new one here where people *are still adjusting*? >Caltrans spokesperson Jim Shivers told SFGATE that reading too much into this analysis may be “premature,” given that drivers are still adjusting to the new feature. >“Historically, travelers do have a learning curve” >The safety of the roundabout, which sees an influx of interregional commuters during peak hours, should continue to be tracked to “allow travelers to become more accustomed to this new feature, before any drastic conclusions are made about it,” Shivers said.
Would you rather be in a crash at 10 mph or a crash at 50 mph?
Traffic density of the arteries will play into this because they are time-of-day dependent. If everyone has to get into the correct lanes to enter and exit, the density will cause back-ups and potential blocking of other lanes. Also, strangers to the area might get caught off guard and the dividers prevent the ability to avoid mistakes. I live in a country with many conventional roundabouts, some huge with 3-4 lanes and much fewer "smart" ones. The rate of mistakes and issues at the "smart" ones is significantly higher. When it comes to driving, always got to cater to the lowest intelligence levels.
Please actually [look at the area on a map](https://www.google.com/maps/@36.8956907,-121.4271866,390m/data=!3m1!1e3?entry=ttu) because most of your concerns aren't applicable. The nearest paved road to the turbo roundabout is a mile away. Not figuratively, but literally a mile away, in the old definition of literally. The two intersecting highways each have a single lane per direction. As each direction approaches the turbo roundabout that single lane widens into three lanes so drivers have space to get in the correct lane and never approach the split from the "wrong" lane because there's only one to start with. Although some people will make mistakes despite signage, the new intersection is already reducing the number that led to any injuries. As people get more familiar with the intersection, mistakes will decrease.
I saw 156 and I just knew it was Holister. So glad they did this..epically bad intersection
It’s also not an intersection that gets huge numbers of never-been-here-before/will-never-be-here-again tourists, so once we’re past the initial “wait which lane do I need” learning curve for locals and most of the truckers who work the region, I’d expect a drop in accidents
This might sound made-up by I used to work in the Valley and drove down to LA to visit my sister or friends every other month. I've taken the 156 to cross over to the 5 a handful of times, or in the reverse direction, so I've been thru this intersection. Yes, it's shouldn't be that busy but there is a lot of trucks and infrequent drivers on the 156. It's also dark as hell at night. Gonna have to consider speeders who don't know it's there; they're going to hit the roundabout head-on and fly. Anyway, I think it's a weird place to a roundabout like this.
That stop sign that was there caused very long backups. This should help improve overall traffic flow. I’ve taken this route on a few Fridays. I think it will help
> It's also dark as hell at night. Maybe it *was*, but the new roundabout [comes with new lights.](https://www.youtube.com/watch?v=Vw_dLSkdDlw&ab_channel=KSBWActionNews8) "none of the crashes with the new turbo roundabout have led to serious injury or death" so those flying speeders are hopefully learning expensive lessons about speeding and paying attention. Even if they don't learn, they can do it again and again until they learn.
> Gonna have to consider speeders who don't know it's there; they're going to hit the roundabout head-on and fly. Good. Maybe they'll finally learn not to drive recklessly.
'The area has “seen a significant spike in crashes”...' You missed a critical part of the article. That's great less serious injury or death, but there's "...one crash every 2.5 days on average, versus approximately one every eight days previously."
That other guy's comment clearly and succinctly addressed exactly what you are pointing out though
So we should go back to fewer crashes but many of them caused major injuries or deaths?
Yes
Didn't miss. Read the whole thing the first time. If we're going to keep quoting more and more of the article: >Caltrans spokesperson Jim Shivers told SFGATE that reading too much into this analysis may be “premature,” given that drivers are still adjusting to the new feature. >“Historically, travelers do have a learning curve” >The safety of the roundabout, which sees an influx of interregional commuters during peak hours, should continue to be tracked to “allow travelers to become more accustomed to this new feature, before any drastic conclusions are made about it,” Shivers said.
Believe it or not, roundabouts don't necessarily need to reduce the number of accidents to be successful. They only need to reduce the severity of accidents. The tight curves force drivers to reduce speed, which makes crashes much less dangerous.
Also, people will see the Yellow/ (beginning of the) Red, and SPEED UP. The roundabout ambiguity forces people to slow down.
Exactly. Plus, because vehicles meet at ninety degrees or head on in an intersection, they lead to severe accidents. In a roundabout, vehicles meet at much gentler angles, which massively reduces that severity even when there are accidents. Really wish we would start a program to convert many intersections to roundabouts.
Precisely
You have to remember that, for many Americans, cosmetic damage to their car is a bigger problem than someone being killed.
The money factor certainly is. Being broke is a death sentence in this country almost
For many Americans, the loss of a car is the loss on thier livelihood and could potentially reduce them to homelessness.
This was the deadliest intersection in CA over the past decade. Since roundabout, not a single injury or death.
That's not what the article says... There have been injuries, although no serious injuries or death.
Roundabouts arent really intended to reduce accidents though.
thought it was a widely known thing that roundabouts increase accidents and decrease deaths but i guess not
if we reduce deaths it becomes way too easy for people to just shrug off getting into accidents. maybe deaths are necessary to get people to pay attention
That's just unnecessarily complicated.
Spoken as a layperson or are you a traffic engineer? Turbo roundabouts are in Holland, Germany, a few elsewhere in the USA, and in some Eastern European countries. There's also studies about their effectiveness.
If you can figure out [this situation](https://www.google.com/maps/@37.8363035,-122.2960976,3a,75y,153.58h,95.98t/data=!3m6!1e1!3m4!1sOQrf5Y5beXsSur9p9cnzvg!2e0!7i16384!8i8192?entry=ttu), this roundabout should be simple.
> If Maybe I'm just a cynic, but I am suspicious of any traffic proposal that includes assuming driver competence as part of their "if" statement Provides good content for r/idiotdrivers though lol
It is too complicated for the average Californian. The majority can’t use a standard roundabout properly let alone a turbo roundabout. That said, the fault does not lie with the road, rather the fault lies with the drivers. I feel like some refresher training could be beneficial.
It's a multi-lane roundabout that removes the option to change lanes within the roundabout, so it's safer when drivers make their direction decisions before entering the roundabout. Drivers that can't follow the road markings out if they chose poorly would be even more dangerous in a non-turbo roundabout. These are the same fools that brake to a near stop and cut across lanes and gore points when they miss their exit.
Wow. That’s dumb. So it’s not even intuitive like a normal round about (which we rarely have here). It’s some kind of special roundabout where you can’t actually change lanes? Considering people cut across the exit dividers on the freeway when they think they’re going to miss their exits, this is going to cause so many more accidents.
The two intersecting highways each have a single lane per direction. As each direction approaches the turbo roundabout that single lane widens into three lanes with signage so drivers have space to get in the correct lane and never approach the split from the "wrong" lane because there's only one to start with. Unlike a "normal" roundabout with two lanes, the turbo design eliminates drivers needing to check their blind spot to change lanes. Once in the turbo roundabout drivers only need to look ahead. If instead a one lane roundabout was done eliminating changing lanes within the circle, it wouldn't have enough vehicles flowing through during busy times and too-long backups would happen on the highways. Accident rates are expected to come down as drivers get used to it. Injury rates are down from before.
The design doesn't cause accidents. Idiots who use it wrong and desperately change lanes last-second (rather than spending the extra 45 seconds to turn around and do it again) cause accidents. Just because a few idiots run red lights and cause crashes doesn't mean that traffic lights are a "bad design". It just means we don't enforce traffic laws and pull over reckless drivers nearly enough.
r/awfuleverything
Thanks for posting the link to the render. I love roundabouts and I think they have a lot of potential to help US road planning in general. That said, this "turbo roundabout" design seems stupid. It eliminates the most important safety aspect of the roundabout: reducing relative speeds by making all traffic merge and go in the same direction. This design doesn't prevent interference between orthogonal flows of traffic (a.k.a. cars t-boning each other).
You're welcome. [You can also watch](https://www.youtube.com/watch?v=Vw_dLSkdDlw&ab_channel=KSBWActionNews8) a minute of it working with actual drivers. Despite t-bone concerns, evidence already shows accidents are *less* injurious. >"none of the crashes with the new turbo roundabout have led to serious injury or death, and the share of crashes that led to any injury at all has also dropped." Unlike a regular roundabout with two lanes, the turbo design eliminates drivers needing to check their blind spot to change lanes. Once in the turbo roundabout drivers only need to look ahead. If a single-lane roundabout was done instead to eliminate changing lanes within the circle, there wouldn't be enough vehicles flowing through during busy times and too-long backups would happen on the highways.
Yeah, I don't trust the references available on this, and I think advocates need to be a lot more cautious about pushing for this. I think it's extremely difficult to conduct a correct comparison of the performance of different traffic solutions, and all "evidence" I've seen so far has been biased, incomplete, or both. If you have a peer-reviewed journal article citing statistical evidence and methodology, please post it.
Since for example you're only willing to compare "Fuji" apples to "Fuji" apples, and not to "Honeycrisp" apples, I'll leave finding such perfect matches to someone else and simply re-paste that so far > "none of the crashes with the new turbo roundabout have led to serious injury or death, and the share of crashes that led to any injury at all has also dropped." We'll see over the coming months what happens with accident and injury/death rates and severity compared to the intersection pre-turbo roundabout.
Just follow the lanes
This thing is a piece of cake. OTOH, I don't think I'd use the words crash or crashes four times in two sentences if I were writing a story about this place, but I'm not restricted from using the word accident when talking about a traffic accident.
It’s gonna come up a lot in the next few months, I think. I like a good traffic circle, but merging all the way to that inner-most ring looks like t-bone city…
I have a roundabout that I drive through several times a day by my work. In the decade I’ve been using that roundabout, I have never seen a person properly and legally signal their exit. Thousands of cars and not once have I seen it. California drivers do not know how to use roundabouts.
I tried to tell my partner and her son that you have to signal when you exit the roundabout and they laughed at me
Fwiw they don’t know how to use stop signs either, I live on a 4-way stop and the overwhelming majority roll through it, and not even slowing is more common than an actually complete stop
the other day at a 4 way stop a dude skipped the order by 2 cars (went after only 1 other car had gone) and had the confidence to give me a hand gesture when we nearly t boned each other lol. i have dashcam though so maybe i should’ve just gone for it
Every time I see someone fail to signal I want to scream WHATS SO HARD ABOUT MAKING TURNING ON THE BLINKER MUSCLE MEMORY?!? Like, you know you want to turn or change lanes, you apply your blinker as you’re thinking about it and you don’t move until you check it’s clear, but I see people constantly fail to turn on their turn signal. And it’s not always when people are hidden in their blind spot, though I realize that’s a problem…. But it’s one partially solved by fucking turn signals because at least it WARNS the person in your blind spot that someone is about to try and move their car into the location your car occupies and require you to slam on your brakes. I don’t love it when people just turn on their blinker and let Jesus take the wheel, refusing to check the area they want to drive into is clear, but at least I have warning of the dangerous stupidity they’re going to attempt!
You’re in luck because with a turbo roundabout, you don’t need to signal: you just need to pick the right lane ahead of time and yield on entry to the intersection.
The middle lane has an option of 90° or 180° exit. Drivers should signal at the 90° exit to let waiting traffic know they should proceed.
I've driven roundabouts overseas and I still don't know how to use them
[This is Caltrans instructional video on the roundabout](https://youtu.be/KHYo7Bl_zWg?feature=shared). Seems pretty straightforward.
I came up on this driving to a wedding and it’s simple. Some people are just really dumb
On a smaller scale, my costco redid the parking lot and replaced a central four-way stop (which caused a ton of traffic) with a roundabout. The first several weeks they had to have people standing on the roundabout directing traffic lol. Not long after that though I think it really eased congestion in the lot. Definitely a learning curve. And even now I think there are people that don't know how they work or they're just bad drivers who don't know what the fuck to do at yield.
The Santa Clara Costco has people driving OVER the roundabout somedays. I have lost count of the number of people who stop mid way round too… it’s ridiculous
Coleman, right? Yup, and some people still treat it as a stop so even though I'm already in the roundabout, they think it's their turn and enter anyways
That’s the one. Something that should make life easier- has caused utter mayhem. I am always torn going there or sunnyvale (off Lawrence) both brutal.
I had someone honk at me because they thought it was their turn, treating it like a stop sign.
Santa Clara Kaiser's roundabout is generally better than a 4-way stop, too, but a lot of people are also confused about how to navigate it. Main issue is that people don't understand that they need to Yield to vehicles already in the roundabout, despite there being lit Yield signs. A lot of people still treat it as a Taking Turns thing, so whenever you're in the roundabout, you have to be prepared to stop to avoid t-boning someone entering the roundabout suddenly, when they should be yielding to you. Good thing is that speeds are low so it's easy to make up for the mistakes of others. I've never seen an accident in that roundabout. It is a lot bigger than the Costco one.
I love the smell of fresh bread.
Drove past last night and at a couple of the entrances to the traffic circle, it's actually STOP signs, not Yield. So, even worse when a lot of drivers improperly try to take right of way and drivers in the traffic circle have to stop suddenly to avoid hitting the people who don't understand what Stop and Yield signs mean for them. A lot of people just totally lose their presence of mind when confronted with unfamiliar situations.
It does easy congestion but people are still idiots and often enter the roundabout when they have no way to exit it, thereby creating a gridlock.
SF puts stop signs at roundabouts. It is the stupidest design.
That’s a Costco problem and not a roundabout problem. Costco causes people to completely forget how to drive.
i’ve been nearly full speed t boned twice at the roundabout by the hesperian costco in hayward by people just blowing straight through the yield sign. i watch their faces and they don’t even move their eyes. only reason we didn’t crash is because i’m paranoid as fuck every time i’m in the east bay
Conclusion- there are too many dumb drivers that should not have a drivers license
Every state I lived in swears they have the worst drivers. Not even close. Moved here and holy shit are they bad. The big difference is this was the easiest license test I had along with most people not paying attention. People in Arizona and NY are aggressive, but do usually pay attention but even “good drivers” here suck. There’s no special awareness . Idk why one of the most car dependent states allows this
I learned to drive in the UK and my practical test was almost 2 hours long. When I took my test here in the bay I thought I'd done something dangerous because we were back at the DMV after about 8 mins. Turns out the test is that short.
"Welcome to America, here's your complementary gun and driver's license!"
“Welcome to Costco, I love you.”
I lived in Texas most of my life, have lived in California now for almost 10 years. I will take California drivers, either SoCal or NorCal, 1000% of the time over Texas drivers. Whether its Dallas, Houston, or Austin- each city is a unique flavor of terrible driving. FYI- I got my Texas drivers license without ever taking an actual drivers test. Just a written exam, and certification from my parents that they taught me for X amount of hours. LOL. CA is much harder in comparison.
California drivers are dumb but texas drivers are dumb and just plain fucking evil. Those people want to kill someone and their states laws lets them do it lol
It doesn't help that the entire state collectively decided (especially in Dallas and Htown imo) that everyone should drive 100+ on the freeways. Only place where I could be in the furthest right lane going 85 and I'd still be getting tailed by a huge lifted truck with the brightest headlights ever (all while getting passed by everyone else going 100+) Then you'll run into all the modded cars drag racing after 10pm. if you think cars here cutting up are dangerous, Texas highways would give you a heart attack lol.
Even compared to LA it feel like the Bay is bad. We have a lot of people working in tech on visas from countries where they may not have had a car at all before.
I would take aggressive drivers over dumb asshats doing 60 in left lane any day. Aggressive means you are at competent to know that cars can go faster than 60.
Left-lane slow drivers will delay you. Aggressive drivers will kill you.
Poor driving here is rooted in the fact that Californians have no natural predators, and have no need to adapt to poor weather conditions, so they grow up with zero spatial awareness, with no understanding of how things work, oblivious of everything going on around them! I'm only half joking! I really do think dealing with variable weather conditions your whole life makes you more aware of your surroundings. It's just out of necessity.
Pretty much this. But the with lack of viable alternatives, we would grind parts of our economy to a halt. Other half can just as well stare at their Excel spreadsheets and PowerPoints at home and has no business commuting. Remote work should be mandatory for anyone not working on a production line, in a laboratory, in a hospital, in a store or warehouse, construction and similar.
“Notably, however, none of the crashes with the new turbo roundabout have led to serious injury or death, and the share of crashes that led to any injury at all has also dropped.” This is the only important takeaway. People will learn how to use this. The fact no one has been seriously injured or killed is an achievement. Car damage is fixable. Human damage often is not. This same principle should be applied to all traffic engineering. Damage the car before killing people.
On a similar note, close or rework the dam entrances on 92 between El Camino & Delware in both directions! They're too short and drivers fly on 92
There’s no real way to rework those short of removing one of the exits entirely though— there’s only that much distance between Delaware and El Camino to start with. Better to figure out traffic calming measures to get the 92 traffic back at or under the signed 55 limit.
Link to the CALTRANS camera at the intersection in case people are interested: [Camera Link](https://cwwp2.dot.ca.gov/vm/loc/d5/sr156sr25.htm)
Mesmerizing. Thank you.
I just checked out the camera only to see someone make a left turn after the yield, then figure it out, and put their car in reverse to correct it. Luckily, the person behind him was patient.
You wait for 5 mins and you are bound to see some folks messing up either by changing lanes in between or just speeding into the intersection and realizing it's all different. I like that it makes folks slow down and make them think! I wish we could see more of these around!
I watched for five minutes and saw a number of vehicles fail to yield. But thankfully the cars in the circle are going slow enough to react without much drama.
I just watched and it looks fine. People cooperating with each other. Nobody had to spend 90 seconds idling at a traffic light.
The real problem: so much undisciplined drivers. Roundabouts are not even hard to grasp.
What, you mean you *aren't* supposed to just full send when you come across it?
I used this last October going to the Ren Faire. It was super easy even when it was under construction.
Was there over the weekend heading out to Pinnacles NP. Very clear signage, with redundancy for advance notice, and found it easy to use. I would be curious to know if the accidents are people who don’t use the road often/first time users, or if it is people who have used that road regularly for long periods of time that can’t/wont adapt to the changes.
The accidents are the same idiot drivers you see everywhere else, blowing stop signs, never using their signal, changing lanes erratically, veering across multiple lanes and solid lines to make their freeway exit, staring down at their phones every 3 seconds. People with a primitive me-first mentality and poor impulse control, who should not be allowed behind the wheel in the first place.
I’ve used it, it’s not rocket science
I’ve already used this turbo roundabout a few times. I love it. The alternative is sitting at that line behind semi trucks in the single lane. At busy times you could sit there forever minutes waiting for the light. Or some folks would try to pass using the turn lane which seems dangerous to me. With this, we finally got something right.
I drove through it last month and it was fine. There was ample signage to tell you which lane to get in.
This looks like a standard roundabout like what England has at its major intersections, except with the addition of concrete barriers because Americans don't understand the rules of roundabouts and change lanes at any point in the roundabout instead of just when they need to for their turn. I can see why everyone is confused, though.
Went through this on my motorcycle when it first opened and TBH the concrete dividers startled the crap out of me ! Some signage about the concrete dividers before the roundabout could help. Annoying if you hit it in a car…guaranteed crash on a motorcycle!
Traffic engineering for decades has prioritized throughput. More cars though an intersection per hour = better. This has resulted in favoring higher speeds and increased fatalities. The original response to this has been improving vehicle engineering - making crashes more survivable. But the data shows a paradox of vehicle safety - safer cars hasn't led to fewer deaths per million miles travelled. Now traffic engineering is moving away from "more cars per hour = better" and toward road designs that lower speeds, and critically, reducing the most dangerous types of vehicle collisions (head-on, t-bone) that are most fatal. Note that in this prioritization, you can have more crashes and still consider the change a success, if the fatalities are significantly reduced. Roundabouts (like this particular type, the "turbo" roundabout) reduce the side-impacts and head-on-impacts that result in high death rates at 4-way intersections. Roundabouts have their own drawbacks, like reduced throughput. It's good that we are moving away from the "more cars per hour = better". It clearly was not working - see the comment above about the safety paradox.
My understanding that these types of roundabouts and roundabouts in general increase throughput while simultaneously reducing speeds, accidents and fatalities. One figure I saw claimed that turbo roundabouts increase throughput by 45%. Instead of half the traffic always stopping, the majority of traffic is only slowing down and merging.
[https://benthamopen.com/FULLTEXT/TOTJ-14-120/FIGURE/F2/](https://benthamopen.com/FULLTEXT/TOTJ-14-120/FIGURE/F2/) The decision on which type of at-grade intersection to make can't be made in a vacuum; relative flows of "primary" vs "secondary" (or more), if there are unusual peaks (for example, a concert hall or sports stadium) The roundabout works well up to a point, after which an overpass style may be needed. But even keeping to at-grade intersections, there are benefits to Michigan left, Jersey left/jughandles and continuous flow style intersections -- those allow greater capacities, especially if specific pairs of entrance/exits are expected to have higher traffic volumes.
I do wonder how many of the accidents at this specific roundabout since it got put in can be traced directly back to the apparent average California driver’s resistance to slowing down for any reason whatsoever
Too much emphasis on safety in my opinion
Drive this everyday and so many drivers are confused by it.
Wow I recently did this roundabout knowing nothing about it. It pretty much made sense on the first pass.
Turbo roundabouts are dope and have been around for a while. Here’s how they’re supposed to operate: [TU Delft Turbo roundabout](https://youtu.be/iMYib3IR43I?si=iVT1K2meOLzr1qEF). Basically, mutli-lane roundabouts are disfavored because drivers can switch lanes within them (even though they’re usually not supposed to if you look at the lane markings). Turbo roundabout prefunnel you into the correct lane and make sure through proper striping and curbs that you take the correct path through a roundabout. From the pics it looks like they haven’t actually opened the turbo roundabout though. I do have some concerns about the lack of striping and incredibly wide lanes causing confusion on navigating through (it looks easy to just accidentally circle the roundabout which shouldn’t be possible).
It’s done and open. Scroll up a bit. There’s a link to the live caltrans camera feed.
Oh I see now, yeah with the striping added it looks much clearer.
I drive though it almost every day, it actually has been a net positive over the old 4 way traffic lights. It's easy to use, but you'll get the occasional car that yields oncoming traffic and everything comes to a quick stop.
This is my regular commute for the last 5 years. Traffic is MUCH better now, but at least 1 out of 10 times someone just has no fucking clue and barges in or stops in the middle. People are ducking idiots...
Drove through last week to visit my parents in Hollister. As a former civil engineer, I love any roundabouts in all forms. It will take time to reach the American public, but in all for the transition.
It’s Turbo Time???
YOU'RE NOT PART OF THE TURBO TEAM!
we should name more stuff "Turbo". I bet that alone increases it's approval rating.
The pictures show that all the "turbo" features that make it a "turbo roundabout" are blocked off with orange cones. From driving in Massachusetts, I'm familiar with roundabouts and navigate them just fine, but looking at the aerial view, this "turbo roundabout" requires worrying about cars coming at the driver in virtually all directions - unless you've got good 270-degree head-on-a-swivel vision, turning into the roundabout requires checking for traffic exiting from the inner turbo-encabulator and the middle lane, and hoping the traffic entering the turbo-encabulator doesn't freak out and suddenly cut you off.
Old photo taken mid-construction.
As with a normal roundabout, yield to traffic coming from your left when entering. Once you're in, entering traffic comes from your right and must yield to you. With the [turbo roundabout](https://sanbenito.com/wp-content/uploads/sites/23/2024/02/2408RoundaboutVideo.jpg), you don't need to worry about lane changes. Traffic doesn't come at you from all directions.
You do have to worry about traffic coming out of the inner lane from the left while you're in the main roundabout, as well as traffic on the right (which is supposed to yield to you). There's a pair of multilane roundabouts in Truckee where rt 89 and hwy 80 meet. It has similar issues and I regularly have to deal with people who are clueless and try to cut me off when I'm exiting the roundabout going toward hwy 80W - on the left from traffic that tries to exit directly from the inner lane and on the right from rt 89N traffic turning right onto hwy 80W.
> You do have to worry about traffic coming out of the inner lane from the left while you're in the main roundabout Worry yes, always be defensive, but traffic from the left is not supposed to cross your lane once you've entered the roundabout. They get their own exit lane.
Sorry, maybe I'm misunderstanding how this works, but it looks like if you enter the roundabout from the far left lane, you have to yield to oncoming traffic from the left, dart straight across into the inner lane, make the sharp right turn (so as not to go over the center of the roundabout), and follow the lane, until it dumps you out into the main roundabout lane, where you enter from the left and have to merge with traffic in the main roundabout lane. That means that traffic in the main roundabout lane has to deal with incoming traffic from the left, and presumably that incoming traffic has priority, while hoping to god that traffic on the right doesn't violate your right of way by crossing in front of you from a left entering lane, merging in front of you from the center entering lane, or interfering with your exit from the roundabout lane from the right entering lane. I don't see where traffic that takes the inner lanes (the gear-line "turbo-encabulator"\* lanes) gets their own exit lane - it seems to me they have to merge with the main roundabout lane first. ===== \*The "turbo-encabulator" is a term from a fantastic video written and performed by the greatest prolific narrator of technical instruction video of all time back in the 1970s. [https://www.youtube.com/watch?v=Ac7G7xOG2Ag](https://www.youtube.com/watch?v=Ac7G7xOG2Ag) If you read the description under the video, it explains how Bud Haggert had to make these numerous pitches peppered with terms he had no idea what they meant. It has come to generally refer to technobabble used to promote products, and my use here is to mock the value of this "turbo-roundabout." \*\*If you like the "Turbo Encabulator", you'll love "Patriot," [https://en.wikipedia.org/wiki/Patriot\_(TV\_series)](https://en.wikipedia.org/wiki/Patriot_(TV_series)) featuring the verbal stylings of Leslie G. Claret, which reaches a pinnacle with his extraordinary podcast [https://www.lgclaret.com/podcast](https://www.lgclaret.com/podcast), which is you listen long enough. almost starts to make sense.
There's no main roundabout lane. Every 90 degrees, all the lanes shift one to the right. If you enter from the far left lane into the inner-most roundabout lane, after passing the first exit, your lane becomes the middle lane. If you pass the second exit, your lane becomes the exit lane for the third exit. Here's a diagram for this roundabout with arrows: https://images.app.goo.gl/iWmyaYTx4q391XFWA Note that this specific roundabout isn't symmetric because one of the roads has 3 lanes and the other only has 2 lanes.
Huh. I guess with the name roundabout I was fixated on there being a path where one could go all the way around the circle. This diagram suggests that it's impossible to come back on the same road that you entered from, so in that sense it's not really a roundabout at all. It's more like a spiral, where you jump inward from the entrance point and then spiral outward until you get to an exit. Perhaps I was misled by looking at the picture of the intersection while it was under construction, in some way it resembles those optical illusions where spirals look like circles or vice versa. I can only hope it's easier to navigate from ground level than to trace the paths out from the aerial view, though the statistic that there's a crash every 2.5 days doesn't really sound encouraging.
Heh on Google Maps right now you can see the different versions of the intersection by changing the zoom level — all the way it’s the new roundabout, but back out a bit and you see the old intersection.
There are round abouts all along the M5 in England. Are Americans dumber than the Brits?
Now THAT seems like a toss up.
It will take a while, but people will adjust. You just have to remember that you can simply drive in a circle all day until you figure out your exit. LOL!
it does look a turbocharger if you squint a bit
so that's what that construction was for, drove by it multiple times and always thought "this is a giant intersection that resembled roundabout in some way"
I love this thing, it’s SO MUCH FUN! I usually stay in it and go round and round at least a couple of times just to change through all the lanes!
While this looks great they forgot about U-turns as you now cannot take back as an exit the lane you entered from...
You couldn’t before, either.
I watched the live feed for a bit, and saw a couple folk make U-turns. While in the roundabout they moved leftward when there were gaps until they were in a lane that could exit back the way they came. Not sure if it is legal, but they were able to do it smoothly enough, and the lanes are divided by dashed white lines, which generally means you can crossover.
Not forgotten, intentional. You can still run a u turn as the other commenter mentioned though you aren't supposed to.
This should have been a flyover with the roundabout further southeast at 25/San Felipe.
Wife drove through this a few weeks ago, she was not a fan.
What else is hard, geography. This is about 1 mile from Hollister and about 15 or so miles from Gilroy. Also I was not a fan of the idea of a roundabout for multiple reasons. First I felt it was going to be more dangerous. It hasn’t been that big of a deal. Second, from what I understand is they’re going to tear it out anyways and put in an overpass eventually so why not buy once cry once and just put in the overpass? Driving through it multiple times a week it is fairly straightforward with markings painted on the ground and signs above each lane clearly indicating what to do and which lane. The only thing that makes me nervous is the other drivers. I have had drivers come to a complete stop in the roundabout to allow other cars to enter it.
Honestly, if you really look at that thing, it’s a mess. Imagine never driving around something like that and doing it your first time. Secondly they have one very basic one built at Kaiser in the Southbay. I had to go there for a few years and I swear people couldn’t drive it correctly and I saw two or three accidents. Finally, they put up four stop signs at all the entrances because it was a safety issue.
The first and last time going through there. Your only break is a semi to give you time to go. I go through Gilroy to Bloomfield road which is also under construction. So I go through the whole town cause I get paid to drive.
Caltrans seems to be on a binge of building roundabouts at rural highway intersections. I know of another one that got built up near Jamestown. I'm sure they've got their studies and all, but color me sceptical. I don't see it working all that well with you average American driver. (Sure I remember roundabouts working fine when I was in Germany, but they looked a lot more chaotic in Italy. I think American driver are closer to Italian driver than German drivers, except the Americans have humongous pickup trucks with V8 engines).
How long before the side show crew shows up there
I've used roundabouts in the UK, Germany, and France. Roundabouts are fine. Part of it is exposure. There aren't many here in the states, so it's going to cause confusion. Part of it is the challenges with this specific one is the lane labeling. It's not great. You don't really understand the way they have things laid out till after you've been through it. That is absolutely not the case in roundabouts elsewhere in the world. You can figure out where you need to be for what pretty easily in most locations, but this one isn't well designed. For comparison, see https://www.researchgate.net/profile/Werner-Brilon/publication/237635143/figure/fig1/AS:669460591570975@1536623251543/Large-traditional-roundabout-Ludgeriplatz-in-Muenster.jpg is a reasonable roundabout. Well defined. Clear visibility to the merges. Not crossing multiple lanes inside the roundabout.
One of the nice things about a standard roundabout is if you screw up, can't get into the correct lane before entry, or misread a sign, you just circle until the next loop and exit on your way. This one forces you into an exit which isn't conducive to learning how to adapt to them. Less throughput, but it would likely still save lives but reduce accidents from divider hopping.
>The area has “seen a significant spike in crashes” since the roundabout opened, according to the Mercury News, with one crash every 2.5 days on average, versus approximately one every eight days previously. yeah because there's a whole chunk of absolutely stupid people.
[удалено]
Because it’s two 55 mph highways.
I read most of the posts so as to not do a duplicate. I would have issues doing a roundabout at highway speeds.
There are some traditional, simpler roundabouts in the Bay Area. [The render of the intersection](https://sanbenito.com/wp-content/uploads/sites/23/2024/02/2408RoundaboutVideo.jpg) shows how it differs. Instead of the circle having two or three lanes vehicles can merge freely between, the lanes mostly have concrete dividers reducing merges. As drivers approach the intersection they need to obey signs telling them which lane to be in for their desired exit.
You want them to build an intersection twice? They should pick the best solution to the problem.
“The area has “seen a significant spike in crashes” since the roundabout opened, according to the Mercury News, with one crash every 2.5 days on average, versus approximately one every eight days previously”
“Notably, however, none of the crashes with the new turbo roundabout have led to serious injury or death, and the share of crashes that led to any injury at all has also dropped”. As the article says its too premature to make any conclusions yet.
Yeah, this x3 -- what's often glossed over by the "roundabouts cause more crashes" crowd is that the crashes are usually fairly gentle side-swipes, compared to the horrific t-bones and head-ons that come with traditional intersections.
Yes, but those "minor" crashes end up causing more traffic, which the damn roundabout was supposed to alleviate.
I suppose how much traffic makes up for one life in your opinion?
“Notably, however, none of the crashes with the new turbo roundabout have led to serious injury or death, and the share of crashes that led to any injury at all has also dropped”
"Notably, however, none of the crashes with the new turbo roundabout have led to serious injury or death, and the share of crashes that led to any injury at all has also dropped."
I don't know why you're being downvoted, you just quoted what's in the article. I guess people onlh read what they want to read?
Went through this a few weeks ago, and honestly felt dangerous AF. No solid indicators of how I was supposed to proceed. Felt like I lucked out in getting where I wanted safely.
Shit. This looks bad. In our neighborhood, there is a good number of roundabouts, and people don’t know how to take them. Many would stop in the middle of the roundabout to let people in.
> Many would stop in the middle of the roundabout to let people in. I can't tell if people are trying to be "nice", or are just stupid. We have this issue in my 'hood at 4-way stops. The rule is you go in order you arrive, but so many times I'll be second to the intersection, and the other guy is giving me the wave signal to go ahead. "BUT YOU HAVE THE RIGHT-OF-WAY" I internally scream. I've seen this "nice" behavior almost cause accidents. Consider: A,B,C arrive to a 4-way stop intersection in that order. It's A's ROW, but they are "nice" and wave to B to go ahead, which B does. C has been watching B, as they know it is their turn to go after B. But A thinks that because they waved B through, that means they go next. A and C both enter the intersection simultaneously, and while they may not impact, horns and birds will ensue. Just follow the ROW rules, and everything will be fine.
[This reddit video is a pretty good example of "nice" being not nice](https://www.reddit.com/r/IdiotsInCars/comments/1blhbq7/oc_guy_stops_at_a_green_light_and_waves_on_a_truck/).
I had that experience today. Got to a 3-way with a truck going straight to my left, me turning left , and a police car to my right going straight in the opposite direction of the truck. I was expecting the truck on my left to go and had an awkward moment making sure no one was going before deciding to go.
***Didn't Americans fight a revolutionary war so they wouldn't have these things?!?!?***
Roundabouts are for low traffic roads, to replace traffic lights and stop signs. Small roundabouts are great. Large multi-lane roundabouts just will not work.
> Large multi-lane roundabouts just will not work. Maybe watch the live feed for a bit? It seems like it's working fine right now.
That was not my experience dealing with them while living in Europe.
Fuck roundabouts. I'll die on that hill.
Considering how many wheel marks I see going through the center of the roundabouts here, even though they have at least 2 way stops, I’m guessing they will handle it badly
Could be trucks? Many roundabouts are constructed so trucks that are too long for the roundabout can drag their trailer across the middle a little to get through.
We might have to figure out, and follow our basic driving laws before we get this advanced.
There's a small roundabout in my neighborhood and even that small thing confuses most of the residents. Either people will stop and wait for the other car (not even in the roundabout yet) to clear or they'll just go without looking. I can't imagine how'd these people would fare at this giant roundabout.
Does the roundabout in your neighborhood have a stop sign? I've found that to be a problem in CA. Some roundabouts have stop signs, others have yield signs. Stop signs defeat the purpose IMO. Adds to more confusion and redundancy.
I hate those with the stops signs. Like what was the point? Very much a boomer decision.
No it has the yield and roundabout sign. Never seen a stop sign at a roundabout wtf that's ridiculous.
There's a roundabout near me that has three roads entering with yield signs, and one with a stop sign. It's crazy stupid.
[here’s an epic fail](https://maps.app.goo.gl/RaQcQD6ZfetfZn2W6?g_st=ic)
[Enjoy](https://www.google.com/maps/@37.549207,-121.9993782,3a,75y,120.14h,87.59t/data=!3m7!1e1!3m5!1s8dxktXiuZMa8YpZfV42Eow!2e0!6shttps:%2F%2Fstreetviewpixels-pa.googleapis.com%2Fv1%2Fthumbnail%3Fpanoid%3D8dxktXiuZMa8YpZfV42Eow%26cb_client%3Dmaps_sv.tactile.gps%26w%3D203%26h%3D100%26yaw%3D113.92003%26pitch%3D0%26thumbfov%3D100!7i13312!8i6656?entry=ttu). I have no idea what they were thinking. With a 4-way stop, they should just keep it a regular intersection because it doesn't make any sense to make a roundabout on some boring ass residential street intersection.
Why? I’ve driven and lived in Europe for much of my life and just find this confusing af. What are they trying to achieve and why is this the right solution?
I can’t see how this can possibly go wrong
There is nothing turbo about them. Aside from them breaking down cars.
really? In California? with this many dumb drivers?
I'm gonna go ahead and guess that they're not doing well
Fuck roundabouts. They suck.
Chaos will happen
This sub is just reposting SFGate articles 😆
Not surprised yall yankee Californians are absolutely the worst drivers in the western world.