The mod kit contains a MAP_ModMap plugin. Duplicate this mod and use it as base line for your map mod.
This mod already has all baseline features setup and is ready for you to extend it.
Roads: A basic road network has been setup in this map, NPC cars drive on the roads and you can change and extend this road network to your liking. Make sure to checkout the road tool section of the documentation.
Busstops: Several bus stops have been setup on the map, this should allow your to already create some routes. Check the bus stop section of the documentation on how to extend it.
Dealerships, Depot, Paint Shops: the basic points of interest have been added to the map, check the Dealerships, Depots and Paint Shops for more information.