Cities: Skylines update adds tunnels and more for free but will

Designer City 2

Cities: Skylines II Feature Highlight #3: Public & Cargo Transportation - Paradox Interactive

How the Hudson Tunnel Project Will Transform NYC Train Travel

Sim City update 7 adds the ability to build tunnels and bridges

Cities Skylines interview Colossal Order – mods

Highway Canal Tunnels - Cities Skylines: Custom Builds

Widening Highways Doesn't Fix Traffic. So Why Do We Keep Doing It? - The New York Times

Turns out you can't build tunnels under water, a tunnel-bridge connection looks even better though. : r/CitiesSkylines

EVERYTHING that is new in the FREE Cities: Skylines update

Cities: Skylines CEO: We're not changing traffic (but natural disasters would be cool)

Plazas and Promenades - Cities: Skylines Wiki