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 write applications that consume that data in an interoperable way. For more information, see GTFS at Google Developers.

Chicago Transit Authority

• GTFS Information at CTA
• CTA at transitland
• CTA at Transit Feeds

Metra Commuter Rail

• GTFS Information at Metra
• Metra at transitland
• Metra at Transit Feeds

Pace Suburban Bus

• GTFS Information at Pace
• Pace at transitland
• Pace at Transit Feeds

General Transit Feed Specification Links

• GTFS Specification Reference
• transitland Feed Registry
• Transit Feeds