Mart on the Move

Proximo in HTML5

A while back I worked with Evan Martin and Joe Hughes on Proximo, an Android app that provides an interface to NextBus. This in turn is built on ProximoBus, my alternative JSON-based interface to the NextBus API that makes it far easier to wrangle in modern programming languages.

In the process of working on that app I learned that the Android development environment suffers from Java's propensity for making simple things complicated. The app quickly turned into a big pile of crazy threads, services and "aidl" files that remind me of everything I hate about desktop application development.

Yesterday I noticed that AC Transit now has a public data feed on NextBus, so I briefly considered extending Proximo to support multiple agencies so that we could ship an "All agencies in the SF Bay Area" version of the app. But I took one look at that code and was put right off. Instead, I decided to try to re-implement the Proximo functionality in the browser, using HTML5 technologies.

The result is ProximoWeb: it does everything that Proximo-the-Android-app does except "favorites", because your browser already has a feature for that. It uses CORS to communicate with the ProximoBus API backend, the offline application cache to make it available when your mobile device has no service (although the predictions can't work in this case, of course) and localStorage as a cache to prevent continually re-fetching the data.

The web development environment still leaves a few things to be desired, but overall this was much easier than the Android app. JavaScript's concurrency model is far simpler: everything's just asynchronous and you provide callbacks, with no threads required, and therefore no complicated concurrency concerns. jQuery makes the DOM manipulation far easier than it used to be too, so I don't feel so annoyed by having to essentially invent my own UI widgets.

Right now it's essentially a direct copy of the Proximo functionality, but it's exciting to me that it should now be a lot simpler to add features that I wanted to add to Proximo but didn't want to invest the time, such as finding stops by geolocation, or presenting maps of stop/bus locations. HTML5 is getting more exciting all the time!

BART launches new API

BART has launched a new API which provides access to their real-time arrival estimates, route and schedule information, and more. Yesterday I did a little work to add BART as a special case to ProximoBus, but the data model is just different enough from NextBus that it's not a straightforward mapping.

For example, NextBus models different platforms at the same station and different stops at the same intersection as separate stops, while BART models a station as a single object with one to four platforms. For the moment I've modeled this as a separate "stop" for each platform at a station, which works okay when you drill down through a route as you do in most NextBus-backed UIs, but doesn't make a great deal of sense when you want to just present the full list of stations as is more common in BART UI.

It seems that some adjustments to the ProximoBus data model will need to be made to support BART. This may mean that the BART part of the API has endpoints that the NextBus-powered parts don't and vice-versa. This is unfortunate, but having some overlap is better than no overlap especially if I can make it so that a generic client can detect what kind of agency it's dealing with and adapt its UI accordingly.

NextBus in Google Earth

The KML output from the vehicle locations endpoint on ProximoBus can be added as a "Network Link" in Google Earth to put realtime Muni vehicle location markers into a view of the city.

Not that useful in itself, but kinda fun. It'd be neat if it could put little 3D bus and LRV models where the dots are, but I'm no 3D artist.

The Death Knell of the Transbay Terminal

(photo by Whole Wheat Toast)

San Francisco's Transbay Terminal was built in the 1930s, in the midst of the depression, to serve as a terminal for Key System, Southern Pacific and Sacramento Northern trains that crossed the Bay Bridge on its bottom deck to and from the East Bay.

Today it serves as the San Francisco terminal of several trans-bay bus lines run by AC Transit as well as San Francisco's Greyhound terminal, amongst others. It's a dark, depressing, grotty building surrounded by homeless people. The Muni stops out front, which still have rail lines alongside them dating back to when streetcars served it until the 50s, are always surrounded by people with tales of how bad luck landed them at the Transbay Terminal and how just a few dollars will help them get home.

Just a block away over at Folsom and Beale they've just finished constructing the Temporary Transbay Terminal. Over the next few months services to the present Transbay Terminal will begin to reroute here so that today's Transbay Terminal can be demolished, leaving room for its replacement: the Transbay Transit Center.

The plans for the Transbay Transit Center are grand and ambitious. It is planned that it will serve not only the six agencies it already serves but also rail services from BART and Caltrain and eventually the high speed rail link between San Francisco and LA which will enter the city on the Caltrain line and use a new tunnel from the current Caltrain station at 4th and Townsend up along 2nd St to the Transit Center.

A far cry from the dank and dirty Transbay Terminal, the Transbay Transit Center will be open plan and light and will have a public park on its roof. If all goes as planned it will serve as a convenient hub for all of the transit systems serving San Francisco.

It's exciting to see such a large investment in San Francisco's public transit systems and in cleaning up the blighted area just south of Market at 1st St and turning into a commuter neighborhood. This project is scheduled to complete in 2015, so who knows if I'll still be around to see it, but it's nice to know that although right now things seem bleak for public transit in San Francisco with Muni raising prices and cutting service there is a bright future ahead.

The Temporary Transbay Terminal is expected to open within the next month and the existing Transbay Terminal is scheduled to close before the fall before being demolished.