When is the next caltrain? (minimal webapp)
18 comments
·August 6, 2025lindig
The public transport service in Hannover/Germany once had a screensaver that you could configure to show the next departure from your nearest station. I thought that was clever marketing. Today you probably could implement this as a web service.
FredPret
Screensavers can / could ping an API?
That train schedule seems like a cool idea in and of itself though.
simoncion
In the Windows 95 days (and probably in the Windows 2000 days, and maybe also today) "all" a screensaver was was an .exe renamed to -if memory serves- .scr.
There may have been some special interface that the program being run was expected to conform to so the screensaver subsystem would invoke it, but (IIRC) a screensaver could do anything an ordinary program could do. (That was the big reason for being cautious about where/who you got your screensavers from.)
mslate
While cool, this does not incorporate real-time data, just the static schedule.
I've explored this--you need 511 API access to obtain real-time data, and to conceal your API key you need to stand up a web application.
Cool proof-of-concept, need to take it to the next level!
eschluntz
I thought about this, but I've seen several times where the signs say that the train is running late, but it's actually there and leaves perfectly on time!
The schedule has been much more reliable since the electrification
nektro
app hard dies if it's unable to get your location. was really expecting the "full schedule" link to show an input box to pick a station
eschluntz
How else m I going to geotarget you with ads? /s
eschluntz
I was frustrated with the existing caltrain websites / apps, so I made a super minimalist one to answer the actual question I have: how long until the next train?
If you're in SF it grabs the next southbound trains, otherwise, the next northbound.
nilsbunger
Very cool. Would be good if it also shows whether it's a local train or limited or express, and/or which stations it stops at.
eschluntz
bullet trains should be displayed in red, but I haven't tested it yet at the right time and I've been too lazy to write tests with mocked time / gps :)
aeternum
Closest station: San Francisco
But there are two SF stations
eschluntz
"22nd st" shows up separately
andreyk
haha nice, the official caltrain schedule is a bit of a hassle to parse...
I have a command line app for this somewhere I wrote a few years back when I was commuting on Caltrain a lot, I should dig it up and publish it. It had some extra pathfinding/fuzzy search stuff. I almost always have my bike with me and I wanted to cover the edge cases where it's faster to bike to a nearby station to catch a bullet or where you can take a train the wrong direction a stop or two for the same purpose.
I wish there a maps app that would build entire itineraries taking into account that you have a bike with you, and ideally your average expected biking speed. It's so annoying to plan any sort of multi-transit itinerary in the bay, you always have to piece things together yourself or get stuck with some nonsense that takes 30% longer than it needs to.
Of course all of this could also be resolved if we had a sane transit system with short intervals.