[2020] Public Transportation

Unlimited Trees and More Vehicles deal with two of the limits. Make sure you read the descriptions though! More Vehicles CANNOT be removed again, so your city will rely on the mod. 81 tiles goes beyond the 25 tile limit. Procedural Objects is a way to get around the prop and building limit - kinda. It turns them into a different type of object and buildings become purely decorative. But it can be used to keep building.

For the road limit, consider removing power lines and pipes. All networks count towards this limit, so you can use mods like Remove Need for Pipes/powerlines or Klyte's Electric Roads. Fences, canals and quays also count here, so remove any you can live without to free up more roads.

Other than build a good public transport network and use the policies to encourage them (and making them free if you can afford it), I'm not aware of ways to increase the usage.

Best of luck! If you need tips on how to make it more efficient, you can always post pictures and/or you save here. I'm not great with it, but we have a bunch of other players who might have some ideas for how to make it even better. :)

Ah yeah, maybe not. At least asking first would be the way to go. :)

But there's always screenshots as well, even if you might need a bunch to give a good idea of what the current system looks like. :)