1. history of free public transit
2. pros and cons of free transportation from ethical perspective
3. pros and cons of free transportation for economy
4.  by observing the rate of unemployment, average income, number of homeless of one city, analysis why the city need free public transit
5. point out high cost of transportation(how people spend on transportation per year, how city spend on operation of free public transportation)
6. relationship between current situation of one city and the necessity of free public transit, take MA and Boston as an example.
7. regulations of free public transit and taxation…
8. find data and graphs