Welcome!
Joe Hughes
the official forum for discussing upcoming changes to the Google
Transit Feed Specification, an open and straightforward way to publish
transportation schedules.
As more schedule publishers and application developers begin to use
the GTFS, it's increasingly important to have a place where users of
the spec can learn of upcoming changes and give feedback about them.
In addition, this group will serve as a public record of the
motivations for changes to the spec.
Before we get into specific plans, I'd like to go over the goals for
the GTFS, so that we can try to preserve the original vision going
forward:
1. Feeds should be easy to create and edit.
We chose CSV as the basis for the specification because it's easy to
view and edit using spreadsheet programs and text editors, which is
helpful for smaller agencies. It's also straightforward to generate
from most programming languages and databases, which is good for
publishers of larger feeds.
2. Feeds should be easy to parse.
Feed readers should be able to extract the information they're looking
for with as little work as possible. Changes and additions to the
feed should be as broadly useful as possible, to minimize the number
of code paths that readers of the feed need to implement. (However,
making creation easier should be given precedence, since there will
ultimately be more feed publishers than feed readers.)
3. Changes to the spec should be backwards-compatible.
When adding features to the specification, we want to avoid making
changes that will make existing feeds invalid. We don't want to
create more work for existing feed publishers until they want to add
capabilities to their feeds. Also, whenever possible, we want
existing parsers to be able to continue to read the older parts of
newer feeds.
4. Speculative features are discouraged.
Every new feature adds complexity to the creation and reading of
feeds. Therefore, we want to take care to only add features that we
know to be useful. Ideally, any proposal will have been tested by
generating data for a real transit system that uses the new feature
and writing software to read and display it. Note that the GTFS
readily allows for extensions to the format through the addition of
extra columns and files that are ignored by the official parsers &
validators, so proposals can be easily prototyped and tested on
existing feeds.
A note about list membership:
While we've tried to make the feed format as easy to use as possible
so far, there are nevertheless subtleties to the specification.
Therefore, we've chosen to limit posting on this list to those who
have already published GTFS data or have written GTFS import or export
software, in order to ensure a certain level of familiarity with the
current specification. However, anyone is free to read the
discussion.
Welcome again to the list, we're looking forward to hearing your
thoughts!
Joe Hughes
Google Transit