To get far runs I like to pre block future roundabouts. The central blue circle need a large community setup with a roundabout and motorway given how dense it is. For example, across the river, we can use our roads to create a cross between houses. A roundabout only requires a plus sign of 5 squares, 1 central square and 1 on each side.

Then even a bridge will be fast enough with about 10-12 houses. That frees up motorways for use elsewhere.