Another technique that helps (especially if you do not have any teleport spells) is to temporarily sell roads to make space. Then you can rearrange like a mini game of Tetris. Then the roads can be replaced. There was a time when there were no spells to help. Many felt that this skill was essential to develop as part of the charm of the game.
Many folks rearrange at the end of each chapter, when you purge the old guest race structures. This opens up a lot of space.
Another option is to delete old culture structures to make room, rearrange, then replace with new culture structures. This can typically be done after major events with lots of prize options.
Just a few thoughts. I am sure there are many more possibilities.