Let us not become overly side tracked with several projects.  Some people focus excessively in the beginning with the quests the game will give you.  They are a time waste for the dedicated player.

We end up with one choice of begging from Facebook contacts in order to get this far.    This is when having a bunch of Facebook friends comes into play (as long as they are playing Megapolis naturally!).    Check on Facebook for Megapolis add me or something like that similar a player will find plenty of groups to join.    Let Me drop a few examples down the page to helpful groups for those too lazy to search for themselves.

You will definitely need to complete each of the research items before you are allowed to start designing and build the best earning buses.    Train as many engineers as you can in order to speed up this process as well as have always them all researching what ever next, never ever working on nothing.    It offers you plenty of time to focus on upgrading the bus station.  Minding not to overlook your water and electricity needs in the process.   

Many people believe the airport is not really worth the time needed to upgrade and you will discover it left out from many peoples maps.    A completely upgraded airport and planes brings in over a million coins where the bus station is over 4 million!  Its a smart choice certainly.    Do not under-estimate how much those airplanes will have to be upgraded - it is immense!