Game developer rasjar presented their own custom traffic system they will use in their driving game powered by Unity. It supports right- and left-hand side traffic, multiple lanes with random lane switches, and one-way and bi-directional roads.
“I’m working on a driving game and empty streets are boring so I spent some time building my own traffic system,” the developer said on Reddit. If you have any ideas what else they could add, feel free to share them there.