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Comment by meredydd | Hacker News Reader

Relevant difference between UK and American pedestrian lights: When you see the "Green man" in the UK, the cars will not cross your walkway. Contrast the US, where cars can and do legally cross an active pedestrian walkway (turning at a green light, turning right on a red light, etc - this tends to alarm British pedestrians abroad!).

At many junctions, this means no cars may have a green light while the pedestrians cross - so crossing diagonally is a natural extension.

(However, most large junctions have workarounds - usually turn-only/straight-only "filter" signals - which allow simultaneous but isolated pedestrian and car traffic. What's unusual about Oxford Circus is that it doesn't.)

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> this tends to alarm British pedestrians abroad

Yes I've experienced that alarm when in the US! I've been going to cross at a green light but cars are still moving across the crossing. Who has right of way?

The pedestrian. You just have to master "the predestrian glare" of making slightly-judgmental eye contact with any drivers that look like they may be wanting to turn into where you want to walk. :)

I wonder how this will work with self-driving cars. Making eye contact is not an option.

The self-driving car detects a human at the edge of the intersection and hesitates briefly. If the human begins crossing, it waits for them to cross; if the human doesn't, the car proceeds cautiously through the intersection, ready to brake smoothly if the human suddenly steps out.

Yup, and furthur refinements can detect intent, hesitation, emotion, and other kinds of social signalling. (Drivers, bikers, and pedestrians will use non-verbal cues to negotiate; this happens in other contexts too)

The first court cases where someone purposefully throws themselves in front of a moving self driving car will be interesting. Obviously I hope this never happens, but it's inevitably going to happen at some point. Hopefully the sensors are gong to be good enough to be able to save those individuals with no injuries. Though I guess from the car's perspective, this is identical to an animal or child darting into traffic, so this will have to be accounted for in some capacity anyway.

Is there training data for suicidal pedestrians? Does it even happen often enough for a vision network to pick up on those queues?

People purposefully jumping in front of (slowly) moving cars is enough of a problem in some parts of the world that basically every car has a dashcam now. Not suicidally though but trying to get compensation.

Well, the sensor system in a self-driving car conveniently fills the role of a dashcam as well. Logged sensor data will make many accident investigations much easier.

What if as the owner of the car I don't want the sensor data released? Will self driving vehicles move toward a (much of) software like model where we only are getting a temporary license and some other entity can change the rules out from underneath? I'm really excited for self driving cars, this is just one more of the many interesting legal/social questions I look forward to seeing debated.

I've watched self-driving cars trying to make a right turn get "stuck" behind a continual stream of pedestrians. Human drivers will eventually aggressively poke through, but self-driving cars are a little too timid for that.

They could move forward very very slowly

That strategy sometimes works with crowds (e.g., home game weekends in college towns). But sometimes, things turn ugly.

Glare at its forward camera.

That can work if there is also an anthromorphasization (put a human-like face that people can relate too). There was another article talkinf along these lines -- a disabled person trying a telepresence bot for the first time at a tech con saya he did not get the usual courtesy or respect. I suspect people didn't pattern match on it being human.

(I also found "glare at its forward camera" funny and ironic -- we humans have a lot to learn about relating to non-humans.)

It is an option, and I think a pretty effective one in the future. If advanced enough, self-driving cars could learn the different cues we give each other to communicate (be it with a car driver, a bike rider, a pedestrian, or any other agent).

It will be very interesting to see how this dynamic evolves over time.

For it to really be equivalent to eye contact, the car needs to somehow signal that it is aware of the pedestrian and their intent.

I can only hope they'll show old-timey clips on a screen, like Flubber's Weebo.

Self-driving cars won't need the glare, because they will be programmed to respect right of way, including but not limited to pedestrian right of way, or the manufacturers will be crushed by recall/repair/replacements costs and defective product liability lawsuits.

Individual drivers are a bigger enforcement problem.

In British terms, the green light temporarily turns your pedestrian walkway into a zebra crossing. You have legal priority, but some drivers are assholes.

Well, arseholes spelling wise, but wankers would be my chosen vernacular in this situation. Agree completely otherwise.

There is actually an official rule: "Remember, if a pedestrian makes eye contact with you, he or she is ready to cross the street. Yield to the pedestrian." [1]

[1] - https://www.dmv.ca.gov/portal/dmv/detail/pubs/hdbk/right_of_...

As a UK resident holidaying in California, I was confused both as a pedestrian and as a driver.

As a pedestrian I learned to claim the right of way and cross when it seemed safe.

As a driver I was unable to resolve my confusion regarding turning on red light. If there were no vehicles queued behind me I would wait for a green light. I would otherwise typically wait for a sufficient amount of beeping from other vehicles to then assume that turning on a red was what I should be doing.

Were you aware that turning right on red is legal in most of the US but chose not to, or did you not know?

I usually choose not to turn on red when driving in the US when when it's busy. I consider it safer to wait for explicit priority.

That's perfectly acceptable if you ask me. I have a cranky manual transmission, I don't want to put myself in a dangerous situation just because I have to accelerate at max speed and possibly stall the engine.

At least, as far as I know there are no mandatory right turn on red laws in effect in the US

I'd never realized this, even after a year of living as a pedestrian in the UK, but this finally answers my question of why the pedestrian lights take so freaking LONG to turn green here. It may be intended as a pedestrian-friendly measure, but it FEELS like an intense annoyance, and the natural result is that everyone just crosses on red.

At least in London another difference is that you don't often see traffic lights across the intersection from cars, so it is harder to peek at the traffic signals and know when your crossing is about to go (or whether that approaching car is going to stop or go through the intersection.) Annoying.

Another difference I appreciate is that UK traffic lights cycle red -> yellow -> green. So, given a red light I have at least 1-2 seconds that's safe, and usually more since the timing can be inferred from traffic patterns (cars won't get a green light while there is active cross traffic). I always look more at the vehicle lights instead of pedestrian lights -- I don't particularly trust drivers to pay attention to pedestrians or our signals...

More accurately the sequence is red -> red & amber -> green -> amber -> red, so you can always tell which state is next.

>Contrast the US, where cars can and do legally cross an active pedestrian walkway

And they get angry when the pedestrian takes the right of way. Cars will consistently enter traffic and try to encourage me to get out of their way, i.e. they've begun their left turn and will continue to move at 5mph through the intersection which has worrying oncoming traffic, while I'm crossing the street at a crosswalk.

being Italian I never assume that cars WON'T cross my way

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