I remember in Illinois seeing a little sign under the stop sign like "4 way", showing you that it was a 4 way stop. Here's a street view: https://www.google.com/maps/@41.8659021,-87.6285001,3a,41.2y...

I don't really recall these in New York, but I went for a search on Street View, and we seem to do the same thing here: https://www.google.com/maps/@40.6700018,-73.9955353,3a,75y,4...

It seems like that if cross traffic doesn't stop, the stop sign doesn't have a marker. If it does, it gets a tag like "ALL WAY". No idea if this is standardized or an artifact of my sampling, or if it varies between states.

(I had to really rack my brain to find a 4 way stop in NYC. Ultimately the satellite view was helpful, they seem to not paint crosswalks if traffic doesn't stop. Seems dangerous! People are going to cross those streets. But I digress.)

In AZ "4 Way" or "All Way" signs are almost always present when applicable. These "Cross Traffic Does Not Stop" signs [1] are common (but not universal) at other intersections.

[1] https://bloximages.chicago2.vip.townnews.com/pinalcentral.co...

The worst variant I know on this idea afflicts several intersections in my daily driving environment (west side of Portland): stop signs with little addenda saying "3-way stop". So one direction doesn't have to stop. And they don't tell you which one it is. Is that car coming from your left going to barrel through, or not? Maybe that's a stop sign over there, maybe not, it's hard to tell from the back. Come on.

that sign (along with cross traffic does not stop) exists in CA, but it's not universal enough to rely upon an absence of that sign meaning a 4 way stop.

My driving instructor* ~20 years ago said that's the reason stop signs are hexagons – you can see it's a stop sign from the other side. Same for why yield signs are inverted triangles – the person who doesn't have that sign can see from its shape what it is.

*this was for an underage moped license

I believe all the international signs have unique shapes and the stop and yield signs are borrowed from there.

No, only the yield and stop signs, and the right of way sign (diamond shaped) have unique shapes. Oh wait, the one way sign too, being a long rectangle. Other signs are shaped according to group: Warning signs are triangular, tip up, signs forbidding or mandating something are round (distinguished by color), and informational signs are rectangular. And one interesting case is the do not enter sign, which is usually curved. That makes it more obvious to someone looking for a turn, but also you can recognize it from behind so you know to go in the far left lane if you plan to make a left turn.

I think there's non-infrequently an "All Way" sign under the stop sign if the crossing street has one too. https://en.wikipedia.org/wiki/All-way_stop But I'm not sure how common that is.

There (should) be a very small rectanglular sign right below the stop sign that says "4 way" meaning there are stops on all 4 corners. I've always thought these were way too small to notice and I wouldn't be surprised if they were often missing.

Those aren't there (at least not reliably) in California. One of the most frustrating parts of driving here for me too.

That is part of why the MUTCD requires that the hexagonal shape of the stop sign not be obscured from either side. That way, you have a clear visual reference if there is an hexagonal sign in the opposing directions.

*octagonal

In New Zealand, the paint markings on the road make it clear. Yellow line across the road for stop, white for give way. Examples here: https://www.nzta.govt.nz/roadcode/code-for-cycling/intersect...

Like any good UI, it isn’t something I could immediately recall, but it is something I mostly unconsciously notice when driving. You can also look for signs, but it isn’t as trustworthy.

I really like this design. The UK has a similar system, where there's always a line across the road whenever road users have to stop or give way. There are different types of lines [1] but even without knowing by heart what each of them means I've always found it obvious what one has to do (based on signs and other road markings).

[1] https://assets.publishing.service.gov.uk/media/560aa6c7ed915...

The states I have lived in always as a “all-way” sign at the bottom of the stop signs to indicate if the crossing streets have stop sign as well