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Show HN: NYC Subway Simulator and Route Designer

buildmytransit.nyc

21–30 of 35 posts

Re: Show HN: NYC Subway Simulator and Route Designer

#21

What's the point of designing custom routes, except I guess for fun? NYC is never going to build any new routes.

That is actually the idea. In this simulator, you design services that run on existing tracks. NYC subway is unique in the world in that there are a ton of interlining as well as quadruple tracks, so there are plenty of opportunity to improve system efficiency without building anything new.

Re: Show HN: NYC Subway Simulator and Route Designer

#23
Your default dwell times are wayyyyy too short.

On high capacity systems, train dwell time becomes the limiting factor on passenger capacity. 30 seconds is generally the minimum possible dwell time a system can manage, 20 seconds might be possible during much lower demand periods. But you’re unlikely to ever achieve better than that.

The London Victoria Line, which runs with 90 second headways at peak, achieves at best 24 second dwell times in central section, but 30-40 seconds is more realistic for most stations.

Don’t forget, dwell time includes more than just passengers getting off and on. It has to include time to open the doors, close the doors (including a 2-3 second visual and audible warning!), perform needed safety checks, and eventually pull away. Those operational components the sandwich the core “people getting on and off” bit of station stops add up to a non-trivial number of seconds.

https://www.researchgate.net/figure/Dwell-Time-and-Passenger...

As a minor note, the NYC subway uses a system of fix automatic blocks, not a moving block system, which is what your simulation appears to use. Moving block systems are dramatically more efficient than fixed block systems. But I have no idea how you would get hold of accurate block locations for the NYC subway.

Re: Show HN: NYC Subway Simulator and Route Designer

#24

Earlier quoted context omitted.

> ZERO public transport from Staten Island to NJ I only see three bridges off the island. Can you walk any of them? Hoboken light rail in Bayonne isn't so far.

There are 4 bridges: Goethals, Outerbridge, Bayonne, and Verrazano. You can walk on Goethals and Bayonne. I was actually thinking a few weeks ago about walking from Elizabeth to Bayonne someday, just for the heck of it.

I forgot about Verrazano! I was only thinking about routes to NJ.

Re: Show HN: NYC Subway Simulator and Route Designer

#25

Your default dwell times are wayyyyy too short. On high capacity systems, train dwell time becomes the limiting factor on passenger capacity. 30 seconds is generally the minimum possible dwell time a system can manage, 20 seconds might be possible during much lower demand periods. But you’re unlikely to ever achieve better than that. The London Victoria Line, which runs with 90 second headways at peak, achieves at be…

> NYC subway uses a system of fix automatic blocks, not a moving block system

Lines with CBTC use moving blocks. That’s the L, 7, and parts of the E, F, M, and R.

Re: Show HN: NYC Subway Simulator and Route Designer

#27

Your default dwell times are wayyyyy too short. On high capacity systems, train dwell time becomes the limiting factor on passenger capacity. 30 seconds is generally the minimum possible dwell time a system can manage, 20 seconds might be possible during much lower demand periods. But you’re unlikely to ever achieve better than that. The London Victoria Line, which runs with 90 second headways at peak, achieves at be…

How do you know all this?

Re: Show HN: NYC Subway Simulator and Route Designer

#28
post #18

Earlier quoted context omitted.

> ZERO public transport from Staten Island to NJ I only see three bridges off the island. Can you walk any of them? Hoboken light rail in Bayonne isn't so far.

Looks like a 2 or 3 mile walk from the nearest public transport stops that I can find. Maybe someone local can find a closer stop. Forest Ave/Goethals Rd North to Bayway Ave at Mckinley St. Edit: This could be a fun game - find the two spots with the greatest ratio of driving vs public transport. I think those two are pretty good candidates. Distance: 2.5 mile. Drive 9AM: 5-9 minutes, 11PM: 4-6 minutes. Public transp…

Another game: when is public transport slower than walking?

According to Google Maps it's not in this case - I'm getting a walking time of 14:37 (!), where the "walk" includes a ferry from Weehawken to Manhattan and the Staten Island Ferry. However Google Maps doesn't seem to know you can walk across the Goethals bridge.

Re: Show HN: NYC Subway Simulator and Route Designer

#29

Your default dwell times are wayyyyy too short. On high capacity systems, train dwell time becomes the limiting factor on passenger capacity. 30 seconds is generally the minimum possible dwell time a system can manage, 20 seconds might be possible during much lower demand periods. But you’re unlikely to ever achieve better than that. The London Victoria Line, which runs with 90 second headways at peak, achieves at be…

Several of those dwell components can be done in parallel.

You don’t need a warning for opening the doors. The warning for closing the doors will overlap with people boarding.

That being said 10s is too low as a default but it can easily be changed to a more reasonable 30s or more.

Re: Show HN: NYC Subway Simulator and Route Designer

#30

I contract out work to MTA, specifically their AI/ innovation teams. I'm 100% showing this to them today just for fun. They'll get a kick out of it.

I'm super curious to learn more about what AI/Innovation looks like for the MTA.

Is any of your/their work published?

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