Show HN: A Simple Highway Simulator
31–40 of 46 posts
Re: Show HN: A Simple Highway Simulator
#32Here's something fun and counter-intuitive: From default settings, set speed variance to 50%, launch frequency to 120 cars/minute, and reaction time to 500ms. Unsurprisingly, this is chaos. Then, keeping those settings, clear the cars and set the target speed to 150km/h. The traffic mostly clears up! Since the cars are going faster, they leave the road sooner, meaning fewer are on the road at a time, fixing most prob…
Something this sim doesn't model that plays a large role in real accidents is the speed differentials during merges. If an offramp moves too slowly and gets fully congested, it starts spreading onto the highway, compounding the problem. Playing Cities: Skylines I've noticed a similar problem when I try to use roundabouts. They're idealized as a way to keep traffic flowing in busy intersections by imposing no stops, b…
Have they fixed the problem where that 'ideal route' even includes not merging left to pass around a stalled lane? It's been seemingly forever since I built a city.
Re: Show HN: A Simple Highway Simulator
#33Re: Show HN: A Simple Highway Simulator
#34Nice. I've wanted to do something like this, as I have a theory about the car pool lanes being worse for traffic. When traffic is bad, car pool lanes are just as backed up typically. When someone wants to get in the car pool lane upon entering the highway, they tend to do so fairly quickly. This can cause a shockwave as someone flies from one side of the highway to the other. The same thing can happen in the opposite…
In the uncounted thousands of hours of driving on the freeway in my life thus far, I've observed:
* Drivers will improperly idle in a lane they feel safe in, refusing to keep right except to pass (this is actually state law where I live).
* Any deviation from a straight, flat, roadway (corners, hills, dips, anything) will cause the flow to slow; even when you can proxy the status of the roadway in front by the tail-lights of all the lanes of cars who /can/ see.
* Apparently no 'big' city anywhere balances jobs and housing. Cities too small to balance anything are also generally too small to notice the issue. (I say this because it seems like everyone is economically incentivized to drive as far as they can possibly stand from work for the cheapest housing; clearly there isn't enough housing near jobs to keep those costs competitively low.)
Re: Show HN: A Simple Highway Simulator
#35Here's something fun and counter-intuitive: From default settings, set speed variance to 50%, launch frequency to 120 cars/minute, and reaction time to 500ms. Unsurprisingly, this is chaos. Then, keeping those settings, clear the cars and set the target speed to 150km/h. The traffic mostly clears up! Since the cars are going faster, they leave the road sooner, meaning fewer are on the road at a time, fixing most prob…
These settings left me with a neverending accident on one lane.
Re: Show HN: A Simple Highway Simulator
#36What I'm missing is right lane preference, that would control how much people obey the rule that you shouldn't be on the leftmost lane unless you are faster then the cars in the right lane in front of you and if you aren't much faster then the car that's next to you on the right lane you should slow down and place yourself after it or speed up and place yourself in front of it.
It's horribly painful to watch two slow cars occupying both lanes next to each other.
Re: Show HN: A Simple Highway Simulator
#37Interesting project! I had fun playing with it. I wanted to test the theory (which I saw in an article posted here on HN a few weeks ago) that a single car slowing right down on a busy highway (e.g. to avoid hitting an animal on the road or similar) can actually cause a traffic jam that goes back miles and can last for hours. I couldn't prove that hypothesis at this scale. I am assuming that the AI drivers have just…
The 200ms default reaction time in the simulation is wildly optimistic. I remember 1500ms from rider training and http://www.visualexpert.com/Resources/reactiontime.html seems to bear that out.
Re: Show HN: A Simple Highway Simulator
#38Some bugs (cars not always breaking when another is standing still ahead; cars crashing at the beginning if you hit launch too quickly), but overall a fun toy to play with. I would like to know what realistic values are though: I know that 200ms reaction time is a good case, but what are actual average cases? It should be set to that by default. Or acceleration speed, is 5km/h realistic? 10? When set to 5, I cannot s…
Lots of cars do 15 km/h/s (that's a 0-60 mph time of ~6 seconds). A basic Honda Civic will be around 9 or 10 seconds, which is roughly 10 km/h/s. 5 km/h/s would feel pretty sluggish.
how many people routinely accelerate at the full rate their car is capable of, every time they accelerate on the public roads?
Re: Show HN: A Simple Highway Simulator
#39Re: Show HN: A Simple Highway Simulator
#40No post on traffic is complete without a reference to the original "traffic hobbyist": http://trafficwaves.org/ from Jan 1998.