I also realised that given the location of the layout, in a square between Franklin, Orleans, Oak and Chicago that I would not have a North to South road running on the layout. So I got the big ruler out and my tape measure and looked at what had to be done to rectify this mistake?
As can be seen from the above picture the result is that it has become easier for me to transition the tracks through the return loop staging. The road to the far left of this picture is only on the drawing for reference to the real location in Chicago, as it represents West Institute Place.
On the layout we have West Chestnut Street, West Locust Street, and depending on the finding out the date the name was changed, West Whiting/Walton Street. To the right, off board, would be Oak Street, and to the left, off board, would be West Chicago Avenue. Franklin Street would run across the front of the layout if I had room, and North Orleans Street would be at the back of the baseboard.
With the upper level elevated track the plan now looks like this.
I'm thinking about using the Micro-Engineering street viaduct, but I have found another dealer who does laser cut Chicago elevated structures in peel and stick wood. I will have to find out more from people who know more than me.