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Comment by ken | Hacker News Reader

This is pretty cool! One thing that bothers me about every traffic simulation I've ever seen, though: all of the vehicles and pedestrians here seem to be obeying the law.

That's just not realistic -- especially on Mercer, which is blocked (both directions) every few minutes in rush hour by some jerk trying to make an illegal turn onto a packed street. I'd say the main causes of traffic blockages that I encounter during rush hour are drivers blocking the box, and pedestrians entering the crosswalk against a red hand. I also see a lot of lane sweeping, too, which I assume is from the influx of drivers from California (where it's legal).

I hope traffic engineers aren't making real-world decisions based on simulations that follow all state laws perfectly, but I fear they are.

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I've had a lot of fun tweaking this setting in Cities:Skylines. There's a user-written mod called Traffic Manager Presidential Edition which lets you enable some (but not all) bad behaviors.

The principle one is entering an intersection that they don't have room to leave, so they're still there when the signal changes and block the cross direction. (Is this AKA blocking the box? That sounds like a regional term.) This is needed to induce most forms of gridlock.

I'd love if it had more support for jaywalking and vehicles stopping in travel lanes with their flashers on. (And then I'd love if I had a lightning-bolt tool where I could just smite them from on high. There probably is a mod for that, actually.)

The feature, for anyone curious what the other rules it'll break are. [0] TMPE is such a great mod for improving the game's traffic simulation. I've spent a lot of time playing with timed traffic light systems. Cities Skylines will also automatically despawn vehicles to prevent massive gridlock that will break your city, and TMPE can disable this assistance for a truly difficult game.

[0] https://tmpe.viathinksoft.com/wiki/index.php?title=Reckless_...

I still don't understand the concept of "jaywalking". Is there something wrong with crossing the road in the US?

yes

cars have dedicated lanes for driving

bikes have dedicated lanes for biking

legs have dedicated lanes for walking

do NOT cross the lanes

Interestingly, the UK doesn't have these laws and has lower deaths per passenger mile.

Just a warning for those visiting the US - crosswalks will only give you a false sense of security in many parts of the the country (bigger cities possibly excepted), many drivers pay 0 attention to them. Had a car narrowly miss me last week in a crosswalk, and honked at me as it whizzed by. I've never witnessed any enforcement of these kinds of violations against the drivers, either.

Honking could also mean "I'm sorry." When you're locked in a car, you have very limited forms of expression...

I really wish cars came with PA systems installed. There are so many situations I encounter every day where it'd be useful:

- "Turn on your lights"

- "Move over"

- "Thanks"

- "Sorry"

- (incoherent obscenities)

- "Have a nice day"

I'm seriously considering picking up some programmable LED sign and wiring these sorts of messages to buttons I can press while driving.

This is one of the many things I miss from cycling when driving a car: being able to just match speeds with someone else and hold a conversation over something that happened.

In the US, you can generally only cross at crosswalks (for sections of roads that have crosswalks,) and only when the signal is in your favor if there is a signal. Beyond that it decays into a bunch of state and local laws.

You can get a ticket in many places for crossing at the wrong spot, or agains the signals, even if you didn't inconvenience anyone.

I take it that (most of) the US doesn't have pedestrian right of way, then? That's concerning; it suggests a whole host of other things around road culture, most of which are worrying. For instance, I predict that drivers are likely to pay less attention to the road, and that collisions with pedestrians are more lethal when they do occur.

I'm starting to see why the stereotypical USian drives everywhere, even in small areas.

Pedestrians have the right of way in the situations I mentioned, but not when "jaywalking."

You're not wrong about the system heavily favoring driver's convenience; and when drivers break the law (even if they injure someone) the punishments are light.

According to the Wikipedia article (https://en.wikipedia.org/wiki/Jaywalking):

> Originally, the legal rule was that "all persons have an equal right in the highway, and that in exercising the right each shall take due care not to injure other users of the way".[8] In time, however, streets became the province of motorised traffic, both practically and legally. Automobile interests in the US took up the cause of labeling and scorning jaywalkers in the 1910s and early 1920s, by then the earlier term of "jay driver" was declining in use.[9][10] The earliest citation in the Oxford English Dictionary follows in 1917.

[8]: Miller McClintock for the Chicago Association of Commerce, "Report and Recommendations of the Metropolitan Street Traffic Survey", p. 133, quoted by Norton, Fighting Traffic, on p. 289.

[9]: Norton, Fighting Traffic, pp. 79-79.

[10]: Peter D. Norton, "Street Rivals: Jaywalking and the Invention of the Motor Age Street", Technology and Culture 48 (April 2007), 331-359 (342). doi:10.1353/tech.2007.0085

I agree with you. However, this may be obvious, but some of that could be due to people trying to follow Google Maps, Waze, or other similar navigation system directions where the routes are generated based on what other users have done.

I drove in downtown Seattle rush "hour" traffic for the first time in almost a year earlier this week, and Maps was giving me all kinds of dangerous, traffic-jam-causing directions. Things like "make a left turn at an uncontrolled intersection, from a side street onto an arterial that's gridlocked for about a kilometer in either direction". Apparently it had been happening for awhile, because the city had installed a barrier across the median, and I couldn't have followed the directions even if I'd wanted to.

IOW, it's not just drivers ignoring the law, it's tech companies explicitly instructing drivers to break the law and cause traffic problems that the simulations need to account for now.

> it's not just drivers ignoring the law

It is. If a driver comes across the situation you described, any action other than a right-hand turn means they should probably take a driver's ed course again. Regardless of what a robotic voice on their phone is telling them.

Google maps once instructed my wife to do a U-turn on Lakeshore Drive. Nope.

Yes, and driver's ed should harp on the concept of ignoring the sat-nav if it's telling you obnoxious things. See my other comment.

I don't think this concept is mentioned anywhere in the current curriculum, and I think a lot of people are ignorant enough of technology to obey it more blindly than they should.

That's certainly the ideal approach, but I don't think it's realistic to plan for normal people behaving that way.

By the time I realized that Google had given me a route that would not work, breaking out of it cost me 10 minutes of sitting in traffic going the wrong way. I think most people would take the "drive like a jerk" alternative at that point, because the sunk-cost illusion is hard to let go of.

A self-driving car is basically just going to do what the mapping software tells it to as well, so the "bad instructions from tech companies" factor is a problem that needs to be addressed specifically anyway.

> instructing drivers to break the law

And the process for reporting a map error or unsafe maneuver instruction is way too complicated to do while moving, but can't be done after you've left the area, and there's no function to just submit a voice note.

Some time back, I gave my old TomTom to a not-very-technically adept friend. I figured a little introduction was in order, and at first, I asked her to interact with the unit while I did the driving.

The first thing I did was ignore every instruction. A few minutes of https://xkcd.com/1837/ ensued.

Because I wanted to drive home the point, you won't break it by ignoring it. If you don't feel like making that turn, don't make it. The voice in the box will just recalculate, it won't get annoyed, it has infinite patience and can recalculate for as many maneuvers as you feel like missing.

This is a crucial bit of understanding that I think many drivers lack, as they blindly try to follow impossible or unsafe maneuvers like the computer's word must be obeyed absolutely.

If I had a button which could project thoughts into other people's minds, but _only one thought_ and once programmed the button can never be changed, I think I might set it to "It's okay, just go past it, turn around, and come back." I think a huge fraction of traffic snarls could be eased by spamming the hell out of such a button.

"Maps apps" consistently give me crazy directions in Seattle, in particular things like trying to turn left onto a busy road from a side street when one block over there's an arterial with a light. I really think the prevalence of crazy directions and Uber/Lyft drivers blindly following them must be hurting traffic flow in aggregate.

Not so much actions that break the law, but rather actions that are just pointless and stupid.

I'd like to explore more realistic behavior at some point. Right now, vehicles will avoid starting a turn if there's not enough time left in the signal, but this is an optimistic estimate assuming nobody else is creeping along on the same turn: https://github.com/dabreegster/abstreet/blob/770507610caf4e4...

Right now, it's hard to get a full day of simulation to complete at all, because vehicles gridlock on really short roads inferred from OSM. Once a realistic amount of traffic can get through at all, then I'd love to simulate some percentage of illegal behavior.

I can't even be mad at people blocking the intersections anymore. I know it's not a valid argument, but if they don't do it, other people will and they'll be stuck there not moving at all.

Seattle is a good example of how bad design can create incredibly bad traffic despite the fact that number of cars are actually not that high. Assign a cop to certain intersections would relief most of the traffic I presume.

Another thing I'd be interested in seeing modeled are the people who squeeze into an exit lane at the very last minute. I've only ever commuted in the LA area but it's one of the biggest contributors to traffic by the freeway interchanges.

There are studies that show merging late actually reduces congestion:

https://www.nytimes.com/2016/10/13/us/why-last-second-lane-m...

An Exit lane is probably a different situation from the one described though, and so different behavior is better.

Yes, I figured I probably wasn't clear enough. I agree with the points in the article but I'm referring to a different situation. For example, the one that kills me every morning is where the 101 S turns into the 134, there are 2 dedicated lanes for the 134 on-ramp (so no zipper merge) but people wait until the last possible minute to force their way into the dedicated lanes and clog both those and the surrounding ones. Similar situation where the 170 S hits the 134.

Yep. Happens all the time going northbound on 280 at the 101/280 interchange in SF. You'll always see at least one person clogging up one of the two 280 north lanes by trying to squeeze into the (almost always near-stationary) 101 north lanes. Then, further up 280, the same thing happens with the 6th Street exit, without fail.

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