Here’s a great video comparing the alternatives:

https://youtu.be/7l9GrGCI_wA

My thoughts from it were 5 or 4 are likely the best balance of cost for public good. 6 is the best long-term option, but the most expensive, and 1 and 3 cost basically the same as 4 and 5, but are just far less effective in terms of improving ridership.