Sewer Pumping Stations, and Main Roads

Moving back to the procedural content:  

We now choose a path between gates and mark them as 'highways' which we will use in the future to make buildings on those stretches more important.  They are marked in the city generation map as yellow roads.

We are also choosing locations for sewer pumping stations.  These are building/locations that sewer lines will branch out from and spread across the city.  The stations show up in the city generation map as purple pixels.

Next Steps:

Create the sewer lines that branch out of the stations
Choose a building along a main road to turn into a 'cathedral'
Create a catacombs network to spread out of the cathedrals