I have 2 monorails. One in SH is in a U shape , not completed, North Pole station. Waiting for the rest of the SH land to complete, which is coming way to slowly. SH land should should stretch as far as the main town goes. It's way short. 75% of my neighbors have hit a billion in SH. We are all ready and the rest the players will be one day.
My other monorail goes around the entire perimeter of Springfield with a station in each corner. When we get new land, I only have to move the tracks at the far end, and eventually the stations. I have more than enough pieces to handle any extension, even all those useless curved pieces.
As far as the tunnels to SH go, I put them in inventory. There was a glitch awhile back which allowed us to remove some of the mountains separating SH from the town. Wish I could get rid of more mountains!