When your airport reaches level 3 you unlock the Cargo Airport buildings and roads, which include the Cargo Airport Terminal, Cargo Aircraft Stand, Medium and Large Cargo Airport Roads, and the Airport Cargo Train Station.
Cargo Aircraft Stands work slightly differently than the passenger stands in that they can be placed alongside any road and do not require a connection to a terminal to function.
This means you can simply add a Cargo Aircraft Stand along a road and connect it to your existing runway using taxiways and you are able to ship cargo in and out of your airport!
However, while the Cargo Aircraft Stand might be all you need to receive cargo planes, it doesn’t make for much of a cargo airport! That’s where the Cargo Airport Terminal comes into play! It can be added to an existing Airport Area creating a dedicated point of departure and arrival for cargo traffic, or it can be the main terminal in its own Airport Area. As airport levels are tied to passengers and attractiveness, a dedicated cargo Airport Area will remain level 1 however.
The Medium Cargo Airport Road and the Large Cargo Airport Road are wide roads with utility buildings separating the lanes. These can be used to extend the Cargo Airport Terminal or as roads in your city, and are able to handle a good amount of traffic. The Large Cargo Airport Road even has a wide area for loading and unloading, making it ideal for high volumes of industrial traffic.
And last but not least is the Airport Cargo Train Station which features 4 train tracks making it ideal for cargo transfers between different areas of your city.
Don’t let the name fool you though! It’s placeable anywhere in your city, so it’s a great option for those areas where the regular Cargo Train Station just can’t keep up with the train traffic.