When I was living in Oakland Uber Pool rides would often be cheaper than taking BART...
Seattle does this, to the tune of a $800 to $500 per employee fine if they aren't provided a transit pass depending on where the employer is located in the city. Employees can self-certify as biking or walking to work once a quarter, but a year long transit pass is less than the fine.
Rather than fining employers for failure to get a transit pass for each employee, they could tax them per employee and just issue the transit passes.
Meanwhile, employees feel better about their emploer giving them a "free" transit pass rather than a tax funded passes for all plan. It creates a surprisingly strong incentice for people to switch companies to one that will give them a transit pass (particularly among the $100+k a year workers).
Employees literally feel jipped when their employer doesn't give them a pass, I don't think you could create this kind of positive incentive to be a transit rider any other way.
Maybe they could make mass transit better so more people would want to use it?
Dedicated lanes, singal priority, off-bus payment and fining employers that don't provide transit passes is a proven way to start the cycle toward high transit ridership.