Cities: Skylines Mass Transit is the fourth expansion pack to Cities: Skylines. Mass Transit was released for Windows, OS X, and Linux.
- New forms of transportation: Mass Transit heavily revolves around new types of transportation, such as ferries, blimps, cable cars and trams.
- Transit hubs: Transit hubs will allow all transport services to come together, allowing citizens to change from ferries to metro stations.
- Transit systems: New scenarios will focus on solving traffic problems and adding new transit systems. New road types, bridges, and canals will allow for varieties for the city.
- New hats for Chirper (and others): Chirper receives new hats, as well as new achievements, unique buildings, and policies.