Board Thread:Questions and Answers/@comment-162.234.79.94-20150913201215/@comment-15636815-20151031040229

Additional streets may be purchased on the "Station Extensions and Themes" tab in the game's Shopright next to the Street Extension. You will see only one additional street at a time. It will be labelled "2nd Street", "3rd Street", "4th Street", or "5th Street", depending on how many streets you already have at that station. If you already have all five streets at that station, you will not see any new street in the Shop at that station.