Hacker News Reader

Comment by dheera | Hacker News Reader

Interestingly I once had a near-accident with a Waymo car because I had a stop sign and thought it was a 4-way stop (which would mean I got to go first since I stopped first), but it was only a 2-way stop, and the Waymo had right of way.

That's right, in California, 4-way stops aren't [edit: consistently] labelled 4-way, so when you come up to an intersection with a stop sign you need to peek around at the transverse road (sometimes in the dark) to see whether or not they also have a stop sign to know whether it's 2-way or 4-way. All while looking out for cars on both sides.

The Waymo car stopped just in time and there was no accident. Not sure if this was because of the safety driver or because its algorithm had seen and extrapolated my car's motion and actively avoided the collision.

(Or if they are advanced enough, maybe they have mapped out all the stop signs in California and have labelled all the intersections that are 2-way stops in which a driver could accidentally think it's 4-way, and anticipate the possibility of an accident in advance at these dangerous intersections. I doubt that though.)

View on HN

This is one of the worst UI decisions around driving in the US, in my opinion. Even if the "all-way" addendum was displayed below every stop sign without fail, the semantics of those two stop signs are so different as to warrant a different color and shape; if you mistake a "stop[just you]" for a "stop[all way]" then it's a really dangerous situation. It's easy to fail to spot the difference with a quick glance.

I'd be interested to see statistics on how many people die at these intersections, I suspect this is one of the needlessly dangerous aspects of driving in cities.

The list of horrendous UI decisions goes on and on. A big one for me is left turn lanes. Often there are 2 left turn lanes (let's call them A and B) and they turn into 3 lanes on the other road (let's call them X, Y, Z) and it's not obvious whether A->X, B->Y, or A->Y, B->Z. I've seen many cases of both instances. They really should paint down colored lanes or something to make it unambiguous.

Leftmost lane takes leftmost lane, other lane takes any other lane.

Easy to say, but that's not true in all places. Here's one where the left 2 lanes are left turn lanes, and the leftmost left turn lane turns into the 2nd from left lane.

Big potential for accident for the right left turn lane to accidentally also turn into the same (2nd from left) lane and crash.

And NO, they don't know a priori that the leftmost lane of the street they are turning into is a left turn lane.

https://www.google.com/maps/@37.3626182,-121.8918193,3a,75y,...

They should seriously hang a HUGE sign like this and make it abundantly clear:

https://imgur.com/a/BLoor05

I've seen that as well and that only ever happens when the left most lane is also an exiting lane. It's not intuitive by any means but it's also consistent so if you know the rules and can see the road ahead, you'll be safe.

Many intersections in my area use curved dashed lines to indicate turn lanes... https://safety.fhwa.dot.gov/intersection/other_topics/fhwasa... One of the stated reasons are intersections with multiple turn lanes, to help drivers know how to make the turn and stay in their lane.

They're usually faded out or nonexistent in most of the roads I frequent. I wish they just painted one lane bright red and another lane bright blue. The whole lane. If it fades 90% it's still in-your-face clear and hard to mistake.

Or if you're worried about colorblind people, use patterns. Fill one lane with random dots and another lane with random stars.

Perhaps I am alone, but after moving to an area with the 'Stop All Way' signs, I initially misinterpreted them as exhorting drivers to stop 'all the way', as in to come to a complete stop.

The first time I saw "Do not pass" signs I thought they meant "Thou shalt not pass" as in "Do not enter"

Too often a "Do not enter" sign is in an awkward place where there are two different roadways side by side, and at a glance it's not obvious which one is verboten. Frustrating UI.

There’s a few ‘Stop: Full stop’ signs in my neighborhood in NYC where cars have to cross over a sidewalk because they realize people’s idea of ‘stop’ is normally ‘drive across sidewalk with blind spots on either end at 10 mph with face in phone’

Stop signs in general are hugely abused as a method of speed limit enforcement.

The (European) alternative of a simple set of rules seems more attractive: at an intersection of two different roads, the larger road has the right of way. When two same-priority roads cross, the driver on the right has the right of way. Ambiguous intersections are governed by yield signs. Only in situations where there is actual danger (bad visibility, dangerous shape of the road etc), then stop signs are used.

When they're scarce, people heed them. When they're everywhere, people instinctively determine that they're kind of meaningless, and respect them only to avoid fines from the police.

Easiest way, and I do this every single time, is treat the Stop sign as a Stop and yield to everyone else sign unless it is explicitly marked as "All-way."

Throw in multiple lanes and its a mess

I don’t know, the “can turn left on green but oh make sure you yield to full speed cars coming right at you first” is pretty bad US driving UI too

Conversely, sitting in the middle of the road with no incursions possible simply because a lightbulb is the wrong color is pretty bad UX. People are going to have to make decisions on when to proceed, and even motorcycle crash statistics indicate that drivers turning left at controlled intersections are much less likely to cause a collision.

How so? Green light means the same thing as if there were no lights at all; you yield to oncoming traffic when you want to turn.

The signal for "safe to turn" is completely different, a green arrow.

It's not mandatory either. You can sit and wait if you want.

Caltrans has a readily available copy of their Manual on Uniform Traffic Control Devices at https://dot.ca.gov/programs/safety-programs/camutcd/camutcd-...

Part 2 is specific to signage. Turn to Part 2B.05:

At intersections where all approaches are controlled by STOP signs (see Section 2B.07), an ALL WAY supplemental plaque (R1-3P) shall be mounted below each STOP sign. The ALL WAY plaque (see Figure 2B-1) shall have a white legend and border on a red background. The ALL WAY plaque shall only be used if all intersection approaches are controlled by STOP signs.

In other words, the intersections you're running into are not in compliance with the Caltrans MUTCD.

Yup, and I run into dozens of non-compliant intersections every day. See my other comment below in which I listed several examples on street view that I dug up within a few minutes.

I understand, but your comment was: "That's right, in California, 4-way stops aren't labelled 4-way" which is true in practice but not any more useful than saying "4 way stops aren't labelled 4-way anywhere" because some intersections may not be up to code.

They are SUPPOSED to be labelled. You can probably get them fixed by reporting it to the local government.

Can you? I can't even get a driver's license renewed.

Yup, I made an edit, I should have said "consistently labelled as 4-way"

"True in practice" is the real truth!

As an Australian I find 4-way stop signs to be a form of madness. They don’t exist here. Put an island in the middle and call it a roundabout, or just choose an arbitrary street to have right of way. Either change makes the rules entirely objective.

I’ve driven in the US and Canada, and I never understood the 4-way stop sign. Why do they exist? Non rhetorical question.

They're good in residential areas with smaller streets - one lane in each direction, and cars on the sides of the road.

With a 4-way stop sign everything works well, and traffic stays slow since you're not going more than one block without stopping: no room to accelerate to fast speeds. Roundabouts take a lot of space. 2-way stops are dangerous because traffic can be going a bit fast for the small roads, and visibility is low. There's a two way stop near my house and it's always hard to see if another car is coming, until they're almost inside the intersection. Most of the intersections in the area are 4-way and they just work.

You can have tiny roundabouts: https://www.google.com/maps/@32.2437203,-110.9539392,84m/dat...

This one is also a 4-way, haha.

These are hillarious when they do implement them in the US. People stop anyway to yield. If anything it makes it a little more dicey to bike through because people also don’t signal when they are exiting.

> Put an island in the middle and call it a roundabout, or just choose an arbitrary street to have right of way. Either change makes the rules entirely objective.

1. What is not objective about "everyone stops"?

2. Picking an arbitrary street to have right of way doesn't sound objective to me!

If you're talking about what happens when multiple people approach, there are rules for that, just like rules are necessary when multiple people are using a roundabout at the same time.

1. It’s not the stopping that’s a problem, it’s the starting. You have to track up to three other vehicles to ensure they have the same perception and are following the same rules as you are. Either of my alternatives significantly reduces this problem.

2. The choice of priority road, once made, makes it not arbitrary. The point is to reduce the complexity of the intersection, by giving one road priority. For the purposes of my argument, it doesn’t matter which one.

3. Relying on the assumption that everyone knows how to act in a situation that requires evaluation of up to three other people’s perception and intention is dangerous and unnecessary.

You have to track up to more than three other vehicles in a roundabout. And they're moving faster. But people manage it.

Nonsense.

We’re not talking about nightmare roundabouts like the “wheel of death” in my city, which are clearly not fit for purpose. We’re talking about roundabouts as an alternative to 4 way stop signs.

In a small residential roundabout there is a single lane going in a circle. Either you can safely enter the lane, or you can not. The roundabout serialises the traffic flow so that a driver entering the roundabout need only deal with the next vehicle in the lane. You don’t have to worry about the (potentially unsignalled) intent of any other drivers, make eye contact with them, time their arrival, etc.

To be honest though, I think you know all of this, and you’re simply engaging with me in bad faith.

> You don’t have to worry about the (potentially unsignalled) intent of any other drivers, make eye contact with them

It's very possible to have situations at a roundabout that aren't binary. It can be legitimately unclear if the person in the next entrance is going to enter the roundabout before you, especially because the exact moment a car counts as "in" the roundabout is a fuzzy measure that people could disagree on. If they're going slower than you, then whether you or they are supposed to yield can be unclear. So you have to handle their intent, not just follow a checklist.

This is a rare situation, but so is having to worry about the intent of other drivers at a 4 way stop.

> time their arrival

You definitely have to time the arrival at roundabouts. Cars can't stop instantly, so any situation that involves yielding means you have to time things.

> The roundabout serialises the traffic flow so that a driver entering the roundabout need only deal with the next vehicle in the lane.

You need to pay attention to other cars coming up too, the ones that will be in front you at the roundabout in addition to the cars that are in front of you while approaching the roundabout. This could easily be more than three.

And if a 4 way stop is experiencing a lot of traffic, it goes into a mode where cars alternate in pairs, so you only have to look at the turn signal of the car across you. This specific case is actually easier than a busy small roundabout!

> To be honest though, I think you know all of this, and you’re simply engaging with me in bad faith.

I'm not engaging in bad faith at all. You're overestimating the problems with 4 way stops, while arguing as if [small] roundabouts are perfect. Neither one is perfect, and neither one is dangerous.

It's not arbitrary. A large street will always get right of way. If there is a grid of smaller streets running through a suburb of similar size, it alternates so every second street is a stop sign.

4 way stops sound like bad design to me, it seems like it would leave room for an aggressive driver to take off when they're not first in to an intersection, bullying their way through.

Roundabouts and standard intersections in Australia do not suffer from this, as in both cases there is a clear right of way. If an accident happens, it's generally obvious who is at fault without the need for dash cam footage.

> It's not arbitrary.

Take that up with the comment I replied to, because they specifically said to choose an arbitrary one.

> If there is a grid of smaller streets running through a suburb of similar size, it alternates so every second street is a stop sign.

So on the positive side that's fewer stops, on the negative side you still have a lot of stops and you have watch out for crossing full-speed traffic every other block.

I'm not saying that method is wrong, but it doesn't sound like a significant improvement.

> 4 way stops sound like bad design to me, it seems like it would leave room for an aggressive driver to take off when they're not first in to an intersection, bullying their way through.

Someone can bully through any small intersection.

> Roundabouts and standard intersections in Australia do not suffer from this, as in both cases there is a clear right of way. If an accident happens, it's generally obvious who is at fault without the need for dash cam footage.

Why would it be obvious less often in a 4 way stop? And since everybody stopped it should be extremely hard to have an accident without both parties being at fault.

And roundabouts do not have perfect clarity either. If I'm about to enter a roundabout, and someone on the crossing street is about to enter in front of me at a slower speed, it can be ambiguous who actually gets into the roundabout first and who has to yield.

That's a rare scenario, but so is confusion at a 4 way stop. If someone enters first, they get to leave first. If two people enter at the same time, the one on the right goes first.

As an immigrant myself, my first assumption had been that the oil industry had lobbied for it, since it's a perfect recipe for frequent, often unnecessary stops and fuel consumption.

My neighborhood (In the Seattle area) has intersections with small, 4 way roundabouts that are combined with 2 way stops (there’s a main street no stop with 2 side streets with stop signs)

It’s madness!

There are a bunch in the bay area as well. Here are a handful in Palo Alto:

https://www.google.com/maps/@37.4461675,-122.1651786,3a,86.4...

https://www.google.com/maps/@37.4505849,-122.162804,3a,75y,3...

https://www.google.com/maps/@37.4522447,-122.1576615,3a,75y,...

https://www.google.com/maps/@37.4250195,-122.1482505,3a,75y,...

Ha! I was about to comment the same. Sacramento has the exact same thing, I regularly heard car accidents on this corner when I lived there. https://goo.gl/maps/YR29vXMf4HnNawT68

Making a left turn? I lived there for 5 years and I still don’t know who has the right away

Combining a traffic circle with stop signs is a recipe for confusion.

One thing that Seattle has going for it here is it's very narrow streets, probably 1/2 the size of that intersection in Sacramento: https://goo.gl/maps/A1epH93AE8R28rZH7

That said, we also have 4-way intersections with no stop signs and no roundabouts. This is complete madness.

> which would mean I got to go first since I stopped first

Careful with that. No one has the right-of-way at four-way stops in some (most? all?) states. Whoever enters the intersection first gets the right-of-way. Same reason you have the right-of-way to finish a left turn after your light turns red, if you were already in the intersection waiting for cross-traffic to clear/stop.

The “right of way” refers to the road, and it must be yielded to the car stopped simultaneously to the right in the US uniform traffic code.

Be careful with reliance on what many would consider to be a fairly obscure right-of-way rule. More commonly if it's not clear someone just waves someone else through. It's like depending on people knowing obscure operator precedence :-)

Following my rule, you would always either yield or verify that they have yielded. Seeing a wave can be a good verification.

The annoying thing from people not knowing the rule is the “Mississippi standoff” with two cars at a 4 way stop sign waving at each other and not moving. :)

Here in Australia, last time I checked, no one is considered to have right of way.

Very one on the road must do everything reasonable to avoid a collision.

That's not what it means.

This must be handled by the city or county level as where I live in California there's usually (always?) a little "4 way" sign under the stop sign when it's 4 way.

Either way, this should be made consistent across the state and all of them definitely should have it added if they don't.

I wonder if I could get them to pay me a meaningful amount to identify all the intersections that need such a label. Like say, a bounty of $X for each non-compliant intersection or whatever. I think I could automate it with some simple perception neural nets. Or does the government just not give a damn about this kind of stuff ...

Please report them in the SF311 app or at https://sf311.org/.

They won't pay you any money, but they're very responsive in my experience. Things usually get fixed.

I'm happy to report the few I found to them.

To whoever downvoted me: I wasn't suggesting that I would not report the ones I already know without pay, but rather that if I was funded, I would be able to carve out time to write code to find non-compliant intersections on a mass scale.

Here in Australia sign upgrades or road modifications or both tend to occur either pre-emptively for no apparent reason in an effort to make traffic flow worse, or only after multiple people have died and the local community has been complaining for a decade.

Usually there's a yellow sign underneath the stop sign saying "Cross traffic does not stop".

I don't know if it's a requirement, but it is common.

Not usual, IME they’re rare. I called SF 311 and requested such a sign at an intersection where people often seemed to be confused (10th and Moraga in the Sunset, IIRC). To SF’s credit, they reviewed the accident history at the location, and a traffic engineer called me back to explain that 1) they did not see a history of accidents there and 2) they don’t like to use too many of those signs, because they don’t want people to assume that the intersection is an ‘all way stop’ if the sign is not present.

Maybe it's a sort of accident marker then.

In my experience that sign is usually only used for higher speed roads

4-way intersections in the US have always bothered me. Roundabouts are a much better solution.

Roundabouts seem great and consistent in Europe but in the US their rules differ from state to state.

For example, in California, people in the roundabout have right of way. But sometimes there are confusing traffic lights in the roundabout:

https://www.google.com/maps/@37.3911304,-122.0805522,3a,75y,...

In New Jersey, on the other hand, sometimes, the subjectively most "major" road has the right of way both going in and out of the roundabout. People already in the roundabout have to actually stop for the major road people to enter the roundabout. If you're on the major road you can theoretically pass through the roundabout and not worry about the fact that it's a roundabout. A couple examples of this is seen here, where you're IN the circle but have to yield to incoming traffic:

https://www.google.com/maps/@40.5027947,-74.8525293,3a,75y,2...

https://www.google.com/maps/@40.5761533,-74.6286047,3a,75y,2...

One of my colleagues jokes that we'll know we have truly self-driving cars when they can handle driving through Powder House Square, one of the Boston area's strangest "roundabouts".

https://www.google.com/maps/@42.4011187,-71.1170306,19.36z

Try as we might to keep chaos at bay with our laws, stop signs, and blinking orange lights, it peeks through the seams when you watch the traffic patterns there.

Sounds like a bad use of a roundabout. I'm not familiar with roundabout theory (?), but it seems they work best on evenly weighted intersections.

They're also used to slow traffic. Because you need to check before entering, all traffic slows, even on unevenly weighted traffic. So still useful.

Although the UK seems to be going towards more lights and fewer larger roundabouts.

This pattern sort-of exists in France too. The smaller streets have appropriate signage.

In fact France has several dozen different signs that as a US driver I had to learn and relearn. My wife who grew up there keeps pointing out my mistakes every time we visit.

I like roundabouts too, but which choice is most appropriate depends on circumstance. The US is big and spacious, which makes spending extra on roundabouts not too appealing in many places. And in some circumstances four-way stops flow more traffic.

> And in some circumstances four-way stops flow more traffic.

There's no way that's true, is it? What circumstances would a four way stop sign allow for more traffic flow than a roundabout?

I'm pretty sure it's purely cost-cutting. Four way stop signs are extremely cheap compared to roundabouts. There's no other advantage that I can think of.

Roundabouts are safer (there is no opportunity for t-boning at a roundabout), faster and simpler to navigate than four way stop signs (a roundabout you just give way to people already on the roundabout, a four way stop sign requires you to keep track of who arrived first and then do a weird dance if you both arrived at the same time, and you still need to watch out for people attempting to go out of turn -- which is not possible with a roundabout)

> There's no way that's true, is it? What circumstances would a four way stop sign allow for more traffic flow than a roundabout?

Heavy traffic. In most situations a roundabout will do better, but when completely saturated, the 4-way has a slight advantage. This is probably due to how 4-way stops with dense traffic develop an predictable alternation pattern that eliminates ambiguity and reduces the clearance requirements.

What I've seen here is that traffic will sometimes back up into the roundabout from a blockage down the road, and then things grind to a complete halt, which a 4-way stop should never suffer from.

There's a 6-way roundabout I know of that frequently has one of the 3 intersecting roads dominate the traffic, so people just go full speed from that road. In that case, the other roads can be completely starved, so a 6-way stop would have been better for those roads in those times.

As for t-boning, you can definitely have someone enter a roundabout early/late and hit another car on the side, or dart in front of a car that's in the roundabout (especially possible if the roundabout is not perfectly circular) and themselves get hit on the side.

And people manage to go "out of turn" in roundabouts all the time, by not yielding, or by tailgating.

Roundabouts can also be a nightmare for pedestrians.

anecdotally, all the 4 way stops I encounter in day to day driving in the SF Bay area are labelled as 4 way or all way

I'm in the bay area and adecnotally it has been very inconsistent for me. Here are a few I dug up in just a few minutes of 4-way stops without 4-way labels. This has led me to mostly disregard the absence of a 4-way label as a source of information.

San Francisco https://www.google.com/maps/@37.7253706,-122.4072718,3a,75y,...

Stanford https://www.google.com/maps/@37.4342864,-122.1680113,3a,75y,...

Palo Alto https://www.google.com/maps/@37.4671732,-122.1480907,3a,90y,...

Los Altos https://www.google.com/maps/@37.3977786,-122.1162461,3a,75y,...

San Jose https://www.google.com/maps/@37.3313026,-121.8797736,3a,75y,...

I'm "that guy" in my area that reports and tracks and eventually shames-via-local-newspapers anything I find like this (and trash dumping etc.) Maybe you could be that guy too? This seems sort of dangerous.

I could, though I really don't have time to drive around on street view and keep doing this. I found these violations within a few minutes, I'm sure I could spend hours and map out several hundred such intersections.

Rather, I would be more interested in mapping out all the violations on a mass scale using neural nets, though I'd want my time funded to do something like that, considering it takes away time I could use to do other things.

I hear you. Our time is limited. But I would argue that most good occurs due to many small interventions. And seeing these interventions and the improvements can encourage others to intervene. Maybe reporting these kinds of issues is too hard and that's the problem? Maybe a blog post describing how you just wasted 25 minutes filling out a web form and how a safety issue like this does not look good for the local governance? (This is all really obvious, but I'm clearly just trying to reframe what "that guy" could mean to you and anyone scrolling by :-) )

The way I deal with that situation is look at the drivers eyes. If they see me it's safe. If they don't, don't give a care if I have right of way.

Can't see waymos eyes but maybe I should consider they see me but will follow the legal right if way from the book they can see that I cant

But a good feature and something that human drivers do - I know the sketchy intersections in my town.

Reply on news.ycombinator.com