The Fall of a Tycoon- A Cautionary Tale

All I do now is upgrade roads - I'm too scared to build anything else! But even when I don't build, I am forced to upgrade. Three nights ago everything was fine. Overnight, though NO CHANGES were made, one road became red and needed upgrading. The next night another one became red - again NO CHANGES to housing had been made anywhere near this road since the update. Today, during the day, the first road that became red suddenly needed another upgrade! I am down to $5000 and a road is wanting a $36,000 upgrade. And if I upgrade that? Another will turn red, no doubt. There are five roads that are yellow but I know I don't have to do anything and they will in turn become red.