Marigold
Marigold is a handcrafted map. Plenty of flat space, a few lakes, and a nice harbour area. Oh, and it has 3 5way pinavia interchanges to handle some of the 11 highway connections.
I used fine road heights and configurable slope limits. Fine road heights ability to toggle between road types allowed me to built some very level crossing and smooth out some slopes which would otherwise get stuck on steep by a road.
11 highways all perfectly parallel
8 rail way connections
6 Air connections
6 ship connections
160k trees
Harbour and the big lake have a sunken water spawn
PS. My experimental rail crossing near the harbour needs a redesign. If you know of any good assets which could help with that please feel free to link in the comments.