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Comment by vegashacker | Hacker News Reader

Somewhat off-topic, but does anyone in SF who rides public transportation agree that Google's Map directions in terms of time predictions don't work? Like they're almost always completely wrong. I wonder if they use scheduled bus times instead of actual ones.

Anyway, I was hoping to be able to plug in something like Routesy to iOS 6 maps, and then I'd be a happy camper.

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We've found that Google has historically had a very hard time in San Francisco, and many other big cities for that matter. The results often seem reasonable at first, but end up being impractical in practice. We've found that getting good routing results in cities like SF requires a lot of attention to detail in each particular city. Google has very smart people, but they can't focus everywhere at once.

Disclaimer, I work at Embark and we make transit apps. (letsembark.com)

Edit: it also doesn't help that Muni often doesn't run on schedule.

It shouldn't matter if they don't run on schedule because every bus/train has a GPS on it from which you can make predictions. iCommuteSF and Routesy (and i'm sure others) use this to give me results that are accurate the vast majority of the time.

There's no universally accepted API for the real-time data unlike the GTFS (General Transit Feed Specification) for theoretical schedules. You can approach some commonality with Nextbus API/scraping (http://www.nextbus.com/predictor/agencySelector.jsp) but not every agency offering real-time data uses it.

So iCommuteSF might very well be doable, but you can't use that everywhere like you can Google Maps with GTFS.

I didn't mean to imply you could do it everywhere. I was specifically replying to the part about "MUNI" in the parent comment. The geo data for current MUNI positions is public data. So if you are making an SFMUNI specific app, there's no excuse not to use it.

Also, I didn't realize that embark also does routing, which is more than iCommuteSF and Routesy do.

Yes, however Muni's own signs at the stops often make inaccurate predictions. As an occasional Muni rider, I've often waited for a bus or a train only to find that it's not in service. There are also frequent "ghost buses", where the minutes count down to zero but no bus shows up.

In other words, although I'm certain the transit apps could stand to improve, I don't think even Muni has accurate data.

Most transit companies don't have a real time feed. The key piece of information is how often the bus runs anyway!

I'm pretty sure Google Maps and a plethora of other applications on the App Store simply use the MUNI schedules (http://www.sfmta.com/cms/mroutes/schedules.htm) for the purposes of "time prediction." Since buses in SF are basically never time due to many reasons (traffic, accidents, once I was on a bus where the trainee who was driving took the wrong exit on the way to Daly City BART and the actual Muni driver on the bus had to take over the wheel) the predictions are never accurate.

The only app that has done me right is Transporter, and I'm pretty sure it scrapes Nextbus or some other service for time predictions.

No need to scrape, even. NextBus has a public API.

I also have noticed this in SF. It becomes most frustrating when I want to travel to a location using routes I am unfamiliar with or don't ride often. This means I can't off the top of my head guess when the next bus would be coming before choosing that bus route. In that case I usually pick a live route app like Transporter to see how long of a wait till that bus comes. Unfortunately, that time spent in another application can prove costly if you are in a hurry.

Totally agree. I use Google Maps for "route ideas" if I don't already know. And then switch to Routesy ASAP for the live arrivals.

Unless specifically indicated as live times, Google uses the scheduled times. I've seen live times in Google Maps in only one area, Portland, OR.

Scheduled times are coming from GTFS feeds that agencies register with Google. As far as I know, Google didn't create a unified live transit predictions/tracking API, which seems to me a rather surprising oversight.

It might be speed. I've written an app for SF using the NextBus API, and it is slow. In the time it would take to return the live times for a particular route at a particular stop, Google has already given me four possible routes (and has helpfully gotten me a glass of water, as well).

True. In my experiences scraping Vancouver's Translink, I can get a prediction in about a second or so, but not fully reliably.

On the other hand, if there's anyone that could speed up receiving, processing, and retrieving lots of rapidly changing data, it might be Google.

NextMuni (Muni's app) is the best for SF imo.

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