Cities: Skylines' Airports DLC is out now. It lets you build your own airports within your cities, placing down terminals, taxi lanes, customising the plane liveries and so on. It also comes alongside a free update for the base game which expands some substantial city customisation options.
Here's the launch trailer for the Airports DLC:
I always like the idea that a citybuilder can contain within it a multitude of other business sims. That's what this looks like. The new airports have a ripple effect on the rest of the city, impacting tourism, industry, and other modes of public transportation. You can build a terminal for freight to come via air, the number of trains will reduce as people choose to fly instead, and you can connect your airport to your city with direct bus and rail links.
In a dev diary posted yesterday, Paradox detailed the changes coming with today's free update. First up, "PlaneAI" has been improved for every airport, DLC and not, including a fix to an old "endlessly circling planes" bug.
There are then a slew of new customisation options. You can now choose what kind of trees grow between directions of traffic on roads, you can buy or sell soil for use in landscaping, you can select the appearance of service vehicles for healthcare, fire, police and garbage, and more. It also includes custom models for trees and vehicles made by community members in Cities: Skylines vast modding community.
You can hit that link for the full patch notes. Or if you want the DLC, you can grab it from Steam for £10.29/€13.