A GTFS dataset from a transit agency, showing the schedules, routes, and shapes files. Dataset from San Francisco BART.
The General Transit Feed Specification (GTFS) defines a common format for public transportation schedules and associated geographic information. GTFS "feeds" allow public transit agencies to publish their transit data and developers to use that data to write applications. The feeds are represented in a series of text files that are compressed into a ZIP file, and include information such as fixed-route schedules, routes, and bus stop data. GTFS datasets are used in a variety of types of applications, including trip planners such as Google Maps, mobile applications, timetable generation software, tools for transit planning and operations analysis, and other categories of applications outlined in this article.
TriMet in Portland, Oregon was one of the first public agencies to try and tackle the problem of online transit trip planners through the use of open datasets that are shared with the general public. In 2005, TriMet approached Google, as well as a few other driving trip planner vendors, and asked if they had any plans on incorporating transit in their trip planners based on public TriMet data[[1]]( . Google was the only vendor to reply to TriMet’s request. TriMet and Google then decided to team up to implement one of the first transit trip planners in Portland.
One of the first issues that TriMet and Google faced was the problem of sustainable data – in order to provide quality trips, the trip planner would need quality transit schedule, route, and stop data in an electronic format that was constantly up-to-date. TriMet worked with Google to format their transit data into an easily maintainable and consumable format that could be imported into Google Maps. This transit data format became known as the Google Transit Feed Specification (GTFS)[[2]]( . In 2005, this trip planning service was launched as Google Transit[[3]]( .
After a successful launch with TriMet, Google Transit offered their trip planner service for free to any agency that formatted and maintained their data in the GTFS format. In 2006, five more agencies were added. Google Transit’s success continued as more and more agencies wanted access to a free trip planner, and were willing to put their data into the GTFS format to get it.
Since its creation in 2005, GTFS has become the most popularly-used data format to describe fixed-route transit services in the world. Many agencies have decided to share their GTFS data openly with the public, while others choose to restrict access only to select partners (e.g., Google Maps). As of January 15, 2016, there were an estimated 1026 transit agencies worldwide, including 864 transit agencies in the U.S., that share their GTFS data openly with the general public[[4]]( . As of December 2, 2019, OpenMobilityData lists 1233 providers with publicly accessible GTFS feeds, 465 of which are in the United States[[5]]( . As of August 20, 2015, Google lists approximately 5900 agencies around the world for Google Transit coverage[[6]]( , however, some of this transit information is probably derived from sources other than GTFS.
Even though many transit agencies created GTFS feeds with the primary purpose of benefiting from the free Google Transit trip planner, application developers, often not affiliated with the agency or Google, quickly realized that they could also create many new types of services based on the same GTFS transit data.
As a result of third-party developer innovation, GTFS data is now being used by a variety of third-party software applications for many different purposes, including trip planning, maps, timetable creation, mobile data, visualization, accessibility, analysis tools for planning, and real-time information systems. In 2010, the GTFS format name was changed to the General Transit Feed Specification[[7]]( to accurately represent its use in many different applications outside of Go
