Tunnel Ratfor iOSSome quick bits about the who, what, and how behind the app.
Train times, alerts, and other subway info is provided by the Metropolitan Transportation Authority (MTA). Tunnel Rat caches MTA data briefly to reduce network use, so arrival times may lag actual conditions by up to a minute.
Tunnel Rat is an independent app and is NOT affiliated with, sponsored by, or endorsed by the MTA. Subway line symbols and the Staten Island Railway logo are MTA trademarks, used under license.
Station, complex, and entrance/exit reference data—names, coordinates, accessibility status, and route designations. Tunnel Rat uses this to map the system’s physical layout and find stops near you. Sourced from New York State’s public open data portal.
Tunnel Rat’s map is powered by Apple Maps through Apple’s MapKit framework, which renders the base map beneath subway lines, stations, and your location. Map data © Apple Inc. and its data providers.
The open specification that defines how transit schedules and real-time data are structured. Tunnel Rat reads MTA data in this format. The standard is maintained by MobilityData and is free and open for anyone to use.
When the MTA issues a service alert, Tunnel Rat uses AI (Claude Sonnet, as of June 2026) to rewrite them into a consistent format you can read at a glance.
You can always tap on any alert to see the original MTA wording. Only the original MTA alert text is sent to Claude—no other data is included.
If you ever see anything incorrect or inaccurate, take a screenshot and report it in the app, or drop us a line at hi@tktk.studio.