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Traffic Simulator

traffic-simulation.de

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Re: Traffic Simulator

#81

Post by 2iP1zbR »

vbtemp wrote: post #27
pc86 wrote: post #19

Earlier quoted context omitted.

This would be a neat reinforcement learning project. > Some places the drivers are so polite to the point it really makes things dangerous I've known people like this, who will approach a 4-way intersection and stop even when they don't have a stop sign and the perpendicular street does.

Places where I've seen it, people who have the right of way take that to mean they get to play "traffic cop". E.g., at a 4-way stop the "extra polite" person who gets there first, instead of going through the intersection first, waits and waves the person who does not have the right of way to go through first, which makes that person (and everyone else) confused, and then causes a lot of slowdown, frustration, etc. O…

this has always bothered me.

if you have the right of way, and you do not take the right of way, in most cases you are effectively disobeying traffic rules and disrupting the flow of traffic.

Re: Traffic Simulator

#82

Post by gnopgnip »

andrewstuart2 wrote: post #25
kharak wrote: post #22

Earlier quoted context omitted.

I've made the same observation. But I don't believe human drivers could reasonably take advantage of high acceleration, at least not as well as the simulated cars here. This is a great showcase of the usefulness of autonomous cars, though. Take humans out of the equation and traffic will flow.

The other thing that really seems to make the biggest difference (in combination with better acceleration) is following distance, which is another thing that presumably gets less important with autonomous cars because you don't really have to account for a relatively slow reaction time or poor braking. The observation on acceleration does make me wonder whether teaching proper merging etiquette better (reach freeway…

Autonomous cars still need to have adequate following distance. Without that one small problem turns into a 10+ car pileup.

Re: Traffic Simulator

#84

Post by Geminidog »

You don't need AI based non linear simulations to see what's going on. The simulation shows that traffic can be described in much simpler terms.

You'll notice that traffic is actually a longitudinal wave that travels through the system. The cars are particles and traffic is crests in the wave.

The wave usually travels backwards against the direction of the cars. The worst type of traffic is when you get a standing wave where the crest of the wave just stays in the same place.

Take a look at the simulation with this knowledge in mind. Then you will actually see the wave.

An elegant solution to alleviating traffic would be to then take techniques that dampen waves in materials and translate them into techniques that work for traffic.

Re: Traffic Simulator

#85

Post by dmurray »

kiliantics wrote: post #80
kevindong wrote: post #65

Earlier quoted context omitted.

A pet peeve of mine when I still drove was when drivers would leave 1-3 car length's in front of their car when stopped at a stoplight. And then after the car in front starts moving, it'd take them a solid second to start inching forward also. The bigger problem was that this type of behavior was the norm to the point where at slow speed intersections with stoplights (e.g. city streets around college campuses), only…

Putting more people through per stoplight doesn't really change much. You just get more people at the next stop light. The light is by far the limiting factor, not the drivers. That's why polite driving actually helps, because you get less people blocking each other and less mishaps, the things that actually slow everything down.

You've never been stopped at a light where the queue was many multiples of the number of cars that could get through in one cycle?

Re: Traffic Simulator

#86

Post by airza »

albertzeyer wrote: post #51

Cities Skylines is very nice for such traffic simulations. https://www.youtube.com/watch?v=yITr127KZtQ ( https://news.ycombinator.com/item?id=17182008 ) ( https://www.reddit.com/r/CitiesSkylines/comments/7h6zr0/traf... ) https://www.youtube.com/c/BiffaPlaysIndie/search?query=lane+... This is frequently posted here on HN. E.g. https://news.ycombinator.com/item?id=25632642 .

In the first video a bunch of cars are crowded in one lane of the double lane road (a problem that plagues much of the traffic in the game)

Re: Traffic Simulator

#87

Post by btowngar »

asdff wrote: post #61
parhamn wrote: post #33

Earlier quoted context omitted.

> who will approach a 4-way intersection and stop even when they don't have a stop sign and the perpendicular street does Not the main point but I never liked how traffic signs aren't affirmative sometimes. In the case of the 4-way usually the stopping direction have a stop sign with a missing "All Way" sign below it. But thats not required in all jurisdictions. Nor is the non-stopping direction 100% sure their stop…

Stop signs are the shape they are so you can recognize them from the reverse for this purpose

Hard to recognize them from the reverse when they're hidden behind a bush!

Re: Traffic Simulator

#88

Post by imtringued »

throwaway0a5e wrote: post #54
fooyc wrote: post #45

The more lanes you add, the more cars you get. Adding more lanes doesn't solve traffic issues. https://en.wikipedia.org/wiki/Induced_demand#Induced_traffic...

"Induced demand" is just a backhanded way of complaining that more people can be served by expansion of a particular piece of infrastructure that you don't like. Nobody ever complains about induced demand on the subway from more frequent service causing more people to decide that's the best option for them. Rush hour is like pouring a 5gal bucket into a sink. You can't reasonably handle that all at once will have som…

The problem with individual cars is that they are less efficient than public transport. If you make a city car friendly you are going to see more inefficient cars fill up the existing road. The problem isn't some induced demand meme. It's that some forms of transportation are inherently more inefficient than others. You can solve traffic problems by increasing lanes if you dedicate those additional lanes to public transport.

Re: Traffic Simulator

#89

Post by Daho0n »

throwaway0a5e wrote: post #50
vbtemp wrote: post #27

Earlier quoted context omitted.

Places where I've seen it, people who have the right of way take that to mean they get to play "traffic cop". E.g., at a 4-way stop the "extra polite" person who gets there first, instead of going through the intersection first, waits and waves the person who does not have the right of way to go through first, which makes that person (and everyone else) confused, and then causes a lot of slowdown, frustration, etc. O…

Or they slam on the brakes at the end of what should be a merging ramp or lane because the fore and aft distances to the other traffic that were good enough for the prior N people would be too close for them.

Well to be fair the distance most people feel fine with is not near what is safe.

Re: Traffic Simulator

#90

Post by mlaretallack »

reallymental wrote: post #4

Perhaps these questions are appropriate for this post. I'm beginning to delve into this space and I've not managed to get any satisfactory answers to these questions, despite my month(s) long search. 1) How does one build a traffic (i.e state-space system), forgetting the visualization aspect of things ? Just generating sparse matrices, and adding elements to interact (add/subtract) from these matrices would be a gre…

For 2, Eclipse Sumo allows import of a road network from openstreetmap.
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