We need 2 things for public transportation.
1) A champion in government willing to convince people to invest in and take public transportation.
2) Commitment from goverment to alternative transportation options.
The champion needs to operate on two fronts: 1) government - getting the commitment and investment we need and 2) public awareness - getting people to see public transportation as a viable option that gives them control over their commute and gets them where they need to go in a reasonable time. Public transportation is literally the only thing that can ease traffic because traffic is literally the presence of lots of cars. The only way to have fewer cars on the roads is to have people riding in NOT single-occupancy vehicles. For that to happen, we need public transportation to be a viable option AND for people to see it as such. Another incentive is the reduction in stress, better health from walking, and getting time back for other things while someone else handles the driving.
The commitment from government is going to need to be multifaceted. We have several great plans that are underfunded or not fully implemented (see the bike plan or sidewalk improvements). We also need to focus on mass transit. The light rail loss was disappointing, but another option that is less expensive and still serves the same purpose is Bus Rapid Transit. It would actually cost less yet serve as many people. We need dedicated bus lanes, higher frequency on high traffic routes, and better timing for our needs.