A pretty small vanilla city block blueprint suitable for 1-1 trains.
It worked pretty well for me, with a base of ~130 blocks and ~300 trains and a steady having ~200 spm. When using this make sure to
- remove stations you don't need
- add signal to add path finding penalties when there are not enough resources in a station (or use another method, like disabling stations)
- add some chain signals for stations that are swamped with waiting trains (so they can 'abort' and find another station)
See Reddit for more information/a discussion on this design.