[pricecomstock]

As someone who both bikes and drives around Brooklyn, I would bet this is going to be nearly a decade of testing. There are so many edge cases that I encounter on almost every single trip, and I just don't see anything but very advanced AI handling it

- obvious, but large numbers of pedestrians and cyclists

- 2 way roads becoming 1 lane where the directions must take turns due to construction, deliveries, or the Uber in front of you stopping in the middle of traffic for a pickup

- resurfaced roads that don't have lines painted on them for weeks or months

- congested intersections where you'd probably need to wait 3 hours to pass through legally, so you have to just pull into the intersection trusting that traffic will clear when the next light turns green

- pittsburgh lefts need to happen for the sake of traffic flow sometimes

- sometimes you need to do very human and assertive "negotiation" to get into the lane you need.

- another comment mentioned Waymo cars just rerouting to the next turn when no cars would let them in. There are a decent number of situations where that will cost you 5-30 minutes of extra trip time

- you can disrupt traffic flow quite badly if you e.g. don't pull up to the crosswalk, and out of the way of cars behind you, while waiting for pedestrians to cross on a turn (humans are also bad at this)

- it's difficult to overstate how often cars/vans/trucks are double parked, changing the lanes available, forcing cars and bikes to improvise lanes. This isn't an occasional thing, this is a 10x on a 15 minute trip thing

[apeace]

- delivery drivers on electric bikes or mopeds zipping the wrong way down the road at 30mph, feeling like they are inches away from colliding with you

- roads completely blocked because of the aforementioned double-parking. If someone is double-parked in a way that prevents a delivery truck from getting through, the entire block gets filled with cars that can't move. Then everyone has to back out, one-by-one.

- situations where a police car or ambulance has their lights on behind you and there is literally nowhere to go to get out of their way other than straight through a red light.

To add to something you said:

> sometimes you need to do very human and assertive "negotiation" to get into the lane you need

I'm generally a pretty slow and careful driver in other places, but having driven around NYC for many years now, I can say that it's basically necessary to be an extremely aggressive driver here. If you want to change lanes, you need to cut someone off. It's just expected. If you don't drive like that, it's almost as if the other drivers don't understand your intention, and you get nowhere. Anyone who's taken an Uber, Lyft, or taxi in NYC knows the way you need to drive to get anywhere in a reasonable amount of time.

I'd honestly be excited if they pulled it off. A robot driving like a real New Yorker, but presumably a lot safer? How cool would that be!

[toast0]

> If you want to change lanes, you need to cut someone off. It's just expected. If you don't drive like that, it's almost as if the other drivers don't understand your intention, and you get nowhere.

This is going to be a major challenge or at least a major change for Waymo. It's been a while since I've driven near one, but they were very timid with lane changes. Also, there was that published incident when the Waymo car tried to change lanes into a bus.

There's unwritten rules about who you can cut off. My experience is from LA freeways, the rules may be different in NYC, but the concept is the same. Buses and other vehicles, usually no, but sometimes. Marked taxis, no. Older vehicle with lots of scrapes, probably no. Also, the proper time to signal your lane change is often after your car is already in the lane enough that you can't be displaced.

[devit]

Why would you not cut off buses and taxis?

They are professional drivers, so you can rely on them being better than the average drivers in difficult situations like having to brake suddenly, so I think you should cut them off preferentially.

[Swizec]

At least in San Francisco a bus is king of the road. They will run a red light at normal speed and just beep beep to tell everyone that this is happening. An abrupt stop isn't possible because people are standing inside and might get hurt.

Same reason why a bus will not suddenly slow down to let you into their lane unless lives are at stake. Which at sub 30mph speeds they're not.

Best to treat a city bus like it's a train.

You can think of being a bus driver in city traffic as a constant trolley problem. As a professional driver, do you risk injuring 50 people inside the bus or 1 idiot on the road?

[toast0]

At least where I drive, taxis drive very aggressively and will win at chicken with me everytime. Sometimes professional means in tune with the equipment and willing to drive at the edge of its capability.

Busses are big and may not stop quickly. If traffic is tight enough that I need to force my way into an opening, traffic may stop suddenly and I don't want to find out if the bus can stop behind me, because if not, I need to shop for a new car and new pants. If things are moving very slowly, then yeah, you can cut them off.

[emodendroket]

Buses take much longer to slow down than cars and the driver also likely can't see you if you cut them off with little room to spare. So besides not wanting to be a jerk there's self-preservation to think about.

[wolverine876]

Do not mess around with big city bus drivers, either on the bus or on the road. They are some of the toughest people in the city. Think of what they deal every day.

[DominikPeters]

> I'd honestly be excited if they pulled it off. A robot driving like a real New Yorker, but presumably a lot safer? How cool would that be!

Part of the attraction of self-driving cars is that they will be safer. But as examples like these show, a significant part of danger in driving is completely intentional, especially in cities. You need to deliberately risk crashes all the time to get anywhere and to discourage others (such as pedestrians) from getting in the way. A lot of driving involves such violent threats. I don't know what fraction of crashes comes from this sort of thing, but it would be interesting to estimate, and it would provide an upper bound on the safety advantage of autonomous cars in cities.

[vdfs]

Also it's interesting that a robot is more capable of doing dangerous aggressive type of driving if you factor in how many sensor and calculation power it have over a human

[ehsankia]

Check out this video they posted recently of them driving in SF, which isn't much worse than NYC.

https://www.youtube.com/watch?v=2CVInKMz9cA

Look how it handles the bike going against traffic or how well it sees the pedestrians from far away. It's also quite a bit more assertive I find than in Phoenix.

[sergers]

If it's gonna full stop like that in NYc, gonna backup traffic...

You can slow down but you generally don't stop for pedestrians j walking or bikes going wrong way.

Pedestrians generally know when to speedup/slowdown to cut through moving traffic (not always the case of course there are accidents).

If the person halts in way of traffic than sure do a full stop.

[wolverine876]

> having driven around NYC for many years now, I can say that it's basically necessary to be an extremely aggressive driver here. If you want to change lanes, you need to cut someone off. It's just expected. If you don't drive like that, it's almost as if the other drivers don't understand your intention, and you get nowhere.

It's beyond that: by behaving in an unexpected manner, and by disrupting the flow of traffic, you are a danger.

[JakeTheAndroid]

To be honest, I'd happily let my car mess up the flow of traffic trying to block the box. The only reason this exists is because everyone decides to enter the box to make the light.

When working in SF without self driving I would regularly not let myself block the box and I'd miss multiple lights. Police need to actually ticket people that do this. I've seen cops sitting at the intersection waiting to ticket people for bypassing traffic by using the carpool freeway entrance while doing fuckall about the blocked intersection causing people to want to choose the HOV option.

I understand that it's a part of driving that a self driving car would need to know how to navigate. But we really should just fix this problem through proper traffic enforcement instead of trying to make self driving cars participate in this completely shitty and unnecessary practice.

[pricecomstock]

I agree with you in principle about not blocking the box. But in practice it's not always like that. Sometimes the actual light timing needs to change. Sometimes the roads need to just be different than they are to prevent bottlenecks, which is a pretty expensive fix

Sometimes you roll up to an intersection, and every time the light turns green, the direction you're trying to go already has all lanes filled by another approaching direction. Every time.

[bobthepanda]

Really, Manhattan is just a terrible place to drive. A horribly congested island with limited ways in and out, that is also sometimes the lowest-cost way to get between the mainland and geographic Long Island. The same goes for the rest of NYC to a lesser extent; shoutouts to Elmhurst and Flushing for being particularly terrible places to drive.

Not a morning goes by without a report of "45 minutes/1 hour to the Holland Tunnel." There isn't really a scalable fix for the solution that involves road capacity.

[wolverine876]

> Really, Manhattan is just a terrible place to drive. A horribly congested island with limited ways in and out ...

Manhattan is a wonderful place to drive, my favorite place to drive by far; it's how I instinctively drive but can't everywhere else. It's the most sophisticated driving, not the lowest common denominator; people have to focus on what they are doing - don't start texting. Like the rest of the island - more people is more life, more energy. That's why people have loved NYC for centuries. (Sorry to get corny, but there are plenty of songs about it.)

> Not a morning goes by without a report of "45 minutes/1 hour to the Holland Tunnel."

If you stop thinking about NYC driving distances as physical, but in terms of time, that's just how 'long' the Holland Tunnel is.

[joshribakoff]

Classic prisoners dilemma. The lanes are blocked because the people up ahead are thinking the same thing.

[klodolph]

My experience... the lanes are usually blocked because some other lane, coming some other direction, has much better access to those lanes because of how the signal timing works at the intersection.

A common scenario is: you're heading east, want to head north. When space opens up heading north, northbound traffic has a green light and fills it up. When you have a green light, there is no space.

[polynox]

I could imagine that left turns like you mentioned would be systematically disadvantaged, but doesn't that just mean you should circle around so that you are going north? If instead you were going west and competing against northbound traffic I find it hard to believe you would be systematically disadvantaged; a space is equally likely a priori to clear out when you have a green as when they have a green, no?

[rcthompson]

Space clears out when traffic upstream starts to move. If the next traffic light upstream is synced to the current one, then space will consistently open up at the same point in the cycle, favoring whichever direction has the green at that point. If the lights are almost but not quite synced, then the "favored direction" will gradually cycle around the intersection over time.

> circle around

This is generally not possible, especially for the kind of intersections that have this problem. There generally is not a short path that would allow you to circle around, and even if there is, it's guaranteed to be completely congested by everyone else trying the same trick.

[bun_at_work]

This is - imo - the biggest issue with traffic everywhere. It's a game theory problem, where being greedy is often the best move.

[curtain]

The spring paradox is a neat example of this: https://youtu.be/Cg73j3QYRJc

The shortest route only remains the shortest if a minority take it.

[asdff]

>Sometimes you roll up to an intersection, and every time the light turns green, the direction you're trying to go already has all lanes filled by another approaching direction. Every time.

The only time I can imagine this happening is when trying to turn left, at which point the solution is to go past the turn, double back, and approach the intersection so you can make the turn from the right.

[jefftk]

Imagine you want to go straight, but there is an overwhelming quantity of traffic that is turning right. And the lights are badly timed, so the traffic on the other side of the intersection does not make any progress during your green light.

[emodendroket]

How expensive can it really be to put up a "NO TURN ON RED" sign?

[rcthompson]

This partly falls under "3 hours to pass through legally", but I would add to this the significant number of major intersections where the marked lanes are completely ignored at all times. For example one intersection I'm familiar with has a single lane out of 4 leading to the highway on ramp. However, probably at least 60% of cars passing through the intersection want to get on the highway, so in practice both of the lanes adjacent to the designated lane are also used to access the on-ramp, resulting in an uncontrolled 3-way merge during a sharp left turn in the middle of an intersection.

Edit: For anyone curious, my particular example is getting on 278 South coming from the southeast on Prospect Ave.

https://goo.gl/maps/ySokhy6uXEPPGoG8A

[crmd]

> one intersection I'm familiar with has a single lane out of 4 leading to the highway on ramp.

I suspected instantly you were talking about the prospect Ave BQE entrance . I make that left off third ave onto Hamilton most mornings, and the difference between being in the first- or second-from-left vs third-from-left turning lane is probably an extra 10 minute delay for exactly the reason you describe. I’m no expert in self-driving cars/line following robots, but I suspect real-world NYC driving is computationally impossible at this time.

[totoglazer]

Yes, this also describes, for example, the next entrance at Hamilton and Hicks. Although there’s it’s narrower so primarily just one extra lane.

[emodendroket]

I used to have a drive home where one of the roads had a single lane that everyone local treated by convention like it was actually two lanes, one lane to go straight through and one to turn right, which worked fine until someone from out of town was driving in it and got in the wrong "lane" or just stayed in the middle

[pricecomstock]

I was curious! But not too curious, since this maybe describes most of the on-ramps to the BQE

[ericbarrett]

> another comment mentioned Waymo cars just rerouting to the next turn when no cars would let them in. There are a decent number of situations where that will cost you 5-30 minutes of extra trip time

I took a wrong turn in heavy NYC traffic once (trying to get to the Lincoln Tunnel on a Friday) and it cost me over 2 hours.

[andrewla]

In Philadelphia driving this is called the "New Jersey" problem -- you miss your turn or your exit and all of a sudden you're on a bridge heading to New Jersey with no real idea of how you got there.

[crmd]

My friends call it getting “Newarked”. If we visit NJ for any reason and miss any turn in Bergen, Hudson, Essex, or Union county, and try to use road signs to get back on track, we end up at Newark Airport Terminal C. It’s like the entire NJ roadway system is a feed network for United Departures.

[black_13]

In Atlanta it’s called the “stone mountain” problem.

[moyix]

I once tried to pass through NYC on the way from Boston to DC and somehow managed to get turned a full 180º around and end up headed back north. On the bright side, superhuman performance might not be a very high bar to clear here.

[darkwizard42]

I mean the way to solve this is to prioritize waiting for a turn over the penalty to missing it.

You would have the same issue if you missed the last exit in San Francisco and got stuck going all the way across the Bay Bridge (can easily hit 2 hours trying to go over and back in traffic both ways)

[pricecomstock]

Sort of. The issue is that it's not just "waiting for a turn", it's often "start changing lanes into a small gap because you know the human drivers will make space and let you in". In which case, what you're saying is "drive more aggressively if there's a large time penalty for not doing so", which is at least a mildly uncomfortable criteria to put into a computer algorithm

[dTal]

>a mildly uncomfortable criteria to put into a computer algorithm

I suspect this is going to be a fundamental issue with AI. Far from some idealized 3 laws of robotics, AIs will need to behave like humans to fit in our society. And that will force us to confront the ways in which we don't follow our own rules - indeed can't follow our own rules, the rules being impractical but a convenient fiction to allow us feel better about ourselves.

[jefftk]

This is already happening, with driverless cars getting rear ended because they come to a complete stop at stop signs.

[emodendroket]

I would call this one pretty straightforward; a driver rear ending someone is almost always liable.

[darkwizard42]

I think it is the same criteria you apply as a human. If you need to get into a lane and make a turn, you will slow down, block your lane and inch in till someone lets you in.

I do think there has to be an aggressiveness level in making maneuvers for an autonomous car. It doesn't mean its unsafe, it just means it could be MORE safe if the time penalty isn't big (a decision that regular drivers have a hard time evaluating since we don't measure our own maneuvers' safety accurately)

[wolverine876]

A flashing sign that says 'SELF-DRIVING CAR' will help. OTOH, other drivers might see deep pockets for a lawsuit.

[ericbarrett]

Actually it was a wrong turn in an unclearly-marked construction zone. I was using Google Maps at the time, but the road change was recent enough (perhaps that same morning) that the big G was wrong.

[throwaway0a5e]

Then you'll just have a car stopped in a lane until someone takes pity on it. That isn't an acceptable solution either.

The solution is to figure out what the traffic rule is based on what the other traffic is doing. But that introduces other pitfalls if you don't do it right.

[darkwizard42]

I mean this is what happens to folks as they try to get into a one-lane exit, someone has to let you in.

I guess one benefit of more autonomous vehicles might be cooperation between vehicles to greatly reduce traffic and congestion in these sorts of situations

[asdff]

The big isssue with lane merging is that you have to be assertive and risky in cities or you are just going to be trapped and no one will let you in. You have to almost dare cars to hit you in order to force yourself to have space. I can't imagine a self driving car ever doing that well. It's an entire dance.

[danenania]

It’s quite a safe assumption that no one wants to get into a crash if they can possibly avoid it, so perhaps all that’s necessary to calculate when a car can “safely” be cut off is whether they will have time to stop, even if it’s an abrupt and unpleasant stop? It’s not pretty, but it’s the same calculation human drivers make all the time in these situations.

[lallysingh]

Why not? They are insured and need to function. A random selection of assertiveness can keep the humans from challenging the cars too much.

[adwi]

> it's difficult to overstate how often cars/vans/trucks are double parked, changing the lanes available, forcing cars and bikes to improvise lanes. This isn't an occasional thing, this is a 10x on a 15 minute trip thing

This is so true. Cars haphazardly double park on either side. Best case you’re dodging and weaving, drifting through the painted lane suggestions. Sometimes you’re just stuck and waiting while one of them decides to move. Always the bicyclists get the raw end of the deal in terms of their safety and priority.

I often wonder what would happen if they removed all parking from one side of the street to make long loading-only lanes, and strictly enforced it to prevent people from stopping on both sides.

If you just had one functioning, unimpeded lane for car traffic I suspect it’d improve traffic conditions considerably, vs. four extremely inefficient lanes for cars (2x parking, 2x driving)

[mattzito]

>I often wonder what would happen if they removed all parking from one side of the street to make long loading-only lanes, and strictly enforced it to prevent people from stopping on both sides.

They do this a lot in midtown - commercial only parking during business hours to allow loading/unloading AND you don't need the cops to enforce it because the traffic enforcement people can just write tickets

[bobthepanda]

just fyi, the traffic enforcement people are cops. Giuliani had them moved under NYPD because otherwise they kept getting assaulted.

[jnsie]

> congested intersections where you'd probably need to wait 3 hours to pass through legally

I cannot imagine how self driving cars will (in the future...) deal with entering the Lincoln/Holland/etc. tunnel. I genuinely don't think you can enter these tunnels even during moderate traffic without breaking at least a few laws.

[ep103]

So honest question, when I'm stuck behind one of these fucking things refusing to take a turn correctly, because it means crossing the white line, what do I do?

With a human driver, I can blare the horn, or, god forbid, get out of the car to talk to them.

But with a driverless car, what do I do? Honk at an empty vehicle that literally has no ears?

[bobbylarrybobby]

I love the idea that driverless cars might lower the amount of honking by reducing the number of people who can respond to a honk

[jrockway]

Someday I'm going to run for mayor of New York City to institute exactly one policy change. I'll add horn detectors to all traffic lights, and every time it hears a honk, it will make the light stay red for an additional 10 seconds.

Yes, I know that I will be brutally murdered on my second day in office.

[steelframe]

I'd give it a matter of hours before the city is inundated with trolls walking and biking around with portable air horns.

[omnicognate]

You've got my vote.

[windowsrookie]

Why are you so angry?

[knowfilter]

Presumably because they have to drive a car in downtown Brooklyn occasionally

This Brooklyn Intersection Is The Worst In The State, Study Finds

https://patch.com/new-york/parkslope/brooklyn-intersection-w...

[MisterTea]

If you were born in NYC like me you develop a deep seeded hatred for the human race.

[Kye]

This would explain all the NYT and Bloomberg articles trying to start fights between different demographics, and the weird aggrieved fixation on the closure of little shops in NYC only known to people on a single street in NYC that wouldn't warrant an international feature anywhere else.

[afavour]

Edit: deleted (sigh, this site)

[Kye]

>> "Be kind. Don't be snarky. Have curious conversation; don't cross-examine. Please don't fulminate. Please don't sneer, including at the rest of the community."

>> "Please respond to the strongest plausible interpretation of what someone says, not a weaker one that's easier to criticize. Assume good faith."

I am, of course, talking about the occasional article that makes noise outside NYC. I'm nowhere near NYC. I have never really noticed which "section" a story in the NYT or Bloomberg is in when it finds its way to me. If it had stayed local, I obviously wouldn't have anything to say about it since I never would have seen it.

That was not a rant, much less one about "the media." That was a gentle rib at New York City media's tendency to self-aggrandize and spill outside in a way that isn't self-aware. I buy all my camera and computer stuff from a little corner shop in NYC and wouldn't mind visiting some day, so this is all in good fun.

[romwell]

Because for New Yorkers, the light in the end of the tunnel is... New Jersey.

[wolverine876]

That's not anger, that's just how New Yorkers talk. Get the ideas and emotions out front, no time for a chit-chat warmup. I love NY. (Truly, I don't hear anger when I read it.)

[emkoemko]

Jesus you shouldn't be driving a car if you are that angry

[romwell]

You stare angrily at the passenger until they unlock the door and let you drive the damn thing through the intersection :D

[xmprt]

Do the same thing. There's still a human behind the wheels.

[da39a3ee]

You sound like a complete dick when you are behind the wheel. Please consider stopping driving. Your role as a driver isn't to correct other people's driving; it's to get you and your passengers somewhere safely, while keeping all other road users safe.

[ogjunkyard]

I see Waymo/Cruise/Zoox autonomous vehicles multiple times a day in San Francisco and every one of these points are something that happens all the time in San Francisco.

Something I didn't see mentioned about NYC was elevation changes and hills, which is something that San Francisco has all over. There are some VERY steep streets in San Francisco, which means that sensors are out of typically alignment in relationship to the road when an autonomous vehicle is at an intersection.

[chubot]

Yeah NYC is crazy. One thing I saw this summer is streets in Little Italy and Chinatown with exactly one lane, and restaurant boxes on BOTH sides in the parking spots.

So if there was a delivery truck that parked to unload, and there were, literally entire blocks of traffic would have to wait behind it.

Sometimes a parking spot would open up between the restaurant boxes. The truck can pull in there a tiny bit but not all the way.

Then maybe there is room for the driver behind to pass. They are scraping by with literally 1 to 3 inches of room, negotiating the space manually.

I can't even see a remote driver handling this situation!

I also think this "testing" won't lead to much concrete in the next 5-10 years. There will be data gathering and spinning of wheels. After all I think by 2016 they were also "testing" in a bunch of places, and 5 years later it's barely deployed.

[jdavis703]

I’ve never driven in NYC, but I have biked and walked it. NYC may have more frequent edge cases than SF, but in terms of being able to handle urban edge cases I think SF is roughly comparable to NYC. In some regards traffic in NYC seems even more predictable. Like there’s been times I thought a motorist would gun it through a red light in NYC as would happen in SF, only to see the driver stop and then feel embarrassed for being overly cautious.

[whimsicalism]

Yeah, Bay drivers are actually way more nuts than on most of the East coast.

[nojs]

If anyone else was wondering:

> The Pittsburgh left is a colloquial term for the driving practice of the first left-turning vehicle taking precedence over vehicles going straight through an intersection, associated with the Pittsburgh, Pennsylvania, area. [1]

I guess that would be a Pittsburgh right where I come from :)

1. https://en.m.wikipedia.org/wiki/Pittsburgh_left

[paganel]

Funny how congested cities resemble each other, I live in Bucharest (one of the most congested cities in Europe when it comes to road traffic) and I checked 7 out of the 9 points you mentioned (I'm too lazy to search for what a Pittsburgh left means and I ignored the waymo-specific bullet-point).

I'll add the numerous cases when you have cyclists (especially delivery guys) and rental scooters coming your way on a one way street. Because of that I always, always check both ways when entering a one way street from a side-street because you never know what may be coming the wrong way "illegally", so to speak.

[jorts]

A Pittsburg left is turning left before oncoming traffic starts moving.

[paganel]

Yeah, saw that now. Guilty as charged, I'm not always doing it but there are certain intersections where you can do it in a relatively safe way (especially if you tilt/move as much as you can to the left before the green-light comes on).

[hiidrew]

happy to see the shout out to the pittsburgh left

[whoisstan]

I live in brooklyn too and cars are an incredible pain, they take away space, stink, honk and are stuck in traffic on the BQE all the time. Replacing cars with a commuter network of self driving cars would be a great upgrade IMO.

[asdff]

I wouldn't be surprised if self driving cars just never go on most roads and only stay on a handful of well mapped and easy to interpret routes. Like how trucks follow certain routes through cities too.

[testfrequency]

Nothing about what you have said is unique to NYC/Brooklyn.

Every major dense city that is piloting self-driving cars has been modeling around most of the scenarios you've described

[wolverine876]

Hmmm ... have you ever driven (or directly observed traffic) in NYC? It's unlike other cities, especially in the US.

[spamizbad]

This problem might get solved for self-driving vehicles by simply banishing non-autonomous vehicles (including bicycles and pedestrians) from the roads.

[gehatare]

Banning all other traffic is of course a solution, but it is hugely unpopular for obvious reasons, so I doubt it will pass.

[antisthenes]

It will happen slowly, through raising the price of individual vehicles (you can already see the trend with electric vehicles - there are almost no affordable sub $30k cars), raising the price of insuring a human-driven vehicle, etc.

It won't happen overnight, and probably take anywhere between 30-50 years, but it's definitely possible in the long term.

[rsj_hn]

The problem with that theory is that auto manufacturers face declining average costs and so are incentivized to produce more cars and sell them for a lower unit price.

This is why the only source of auto inflation is by adding more features to the car. I don't see any reason why this would change in the future.

For EVs, wait until cheap Chinese EVs flood the US market.

[circular_logic]

That sounds like it would further increase car dependence in city's, how you see city's improving in this scenario?

[spamizbad]

oh I'm absolutely not saying this is a good idea. But what I am saying is that it could become politically feasible if tons of money gets poured into self-driving vehicles and they slowly chip away at "open" use of public streets.

Look at what the automobile industry did with "jaywalking" and removal of street cars.

[dheera]

or you can do a san francisco mission left:

- if you're turning left, pull forward until you are into the second half of the intersection but don't actually cross into the opposing traffic

- cars behind you can still navigate around you

- when the light just turns red and the opposing traffic stops, finish the left turn. you're blocking the cross traffic that just turned green anyway so you're safe from that.

[gkop]

The yellow light should be long enough for both one last car in the through direction, and one left turner. At least, that’s common outside of SF. I see your point in SF. Anyone care to comment on this? Could it be a combination of short yellows, relatively wide lanes, and nonexistent enforcement (and therefore diminished fear of all parties crossing a red light)?

[dheera]

In SF usually at the yellow light there are about 5 cars that blast through in the opposite direction at 2X the speed limit. The safest time to actually make the left turn is after it turns red, and you're, um, blocking the intersection.

Protected left turn signals are the correct solution to all of this IMO, and that's the norm in almost all of South Bay.

[gkop]

Thanks! Why are you so confident on protected lefts? Wouldn't we lose significant throughput? Why not just ticket people for running reds?

[dheera]

Most protected lefts have sensors so they don't go through that phase if nobody is waiting for it. The sensors are another issue because they don't trigger for bikes and ebikes, but that can be improved.

I think throughput isn't really a huge issue as long as you have a few main arteries (e.g. expressways, freeways) that don't have left turns at all, you will ideally only take the local roads for a couple km at the beginning and end of a trip at most.

[freediver]

Decade of testing or more likely… never?

[kirillkh]

Replace "New York" with "Tel Aviv", and nothing else needs to change.

[dml2135]

Great summary. This will be an interesting experiment that I think will ultimately fail.

[FuckButtons]

On the basis of what evidence? Seems quite pessimistic given that waymo has been stepping up its activity in sf considerably over the last year.

[beepbooptheory]

Just curious more than anything, has there been any model/ai/robot-car that has even come close to responding to the kinds of nuances described above? It seems like so far we are just celebrating that the cars that can stay in a lane, not hit things, which is a huge I get it, but I don't see how sophisticated CV heuristics could even come close to approximating the kinds of edge cases that exist here, both in the social sense of communicating with other drivers, and responding to things that should not be the case (no lines on a road, a double parked car), but in practice are the case everyday in cities.

[ra7]

There are videos of Waymo successfully negotiating a Costco parking lot. Here is a recent video of some scenarios in SF that are close to the nuances described above: https://www.youtube.com/watch?v=2CVInKMz9cA. Notice how there are activity icons indicating pedestrians running, truck stopped with a door open and so on. They can understand a scene pretty well.

Behavior prediction is a large research focus now according to Waymo, so they are thinking about complex situations like these. But a lot of them (like no lane lines, construction, 2 way roads becoming 1 way) can just be encoded in HD maps and distributed to the whole fleet.

[whimsicalism]

Yes, I routinely drive next to these driverless things and they are negotiating plenty of annoying & complicated stuff. I think I must live in a peak location because they are everywhere in my neighborhood in SF, which has lots of fast cars and pedestrians and bikers and skateboarders doing all sorts of crazy things.

Like these actually exist, I guess people on the East coast don't realize it yet?

[ximeng]

https://m.youtube.com/watch?v=TFEvkmvIjVo Clearly not perfect in how it handles this as it doesn’t really back up or go onto the sidewalk but these Chinese self-driving cars are handling quite difficult scenarios.

It’s like there’s a phase transition from theoretical ideal driving to ignoring street markings and navigating based on how much space there is around you and intentions of surrounding vehicles. Looks difficult but not impossible.

There are similar videos showing Teslas handling double parked vehicles and oncoming traffic too.

[FuckButtons]

My old neighborhood in sf was crawling with these things negotiating all kinds of traffic conditions. It doesn’t seem like that much of a stretch to me having driven past and alongside on the order of dozens of these things.

[emodendroket]

I don't envy the people involuntarily enlisted to be "beta testers" by being in proximity of the cars.