For example it may make sense to charge more for luxurious buses, or for a buses that drive on a dedicated lane for which they pay a more expensive license but are faster, or buses that offer wifi, or buses that come by every five minutes, or buses that drive at 3am. These all have fundamentally different cost components. Does the government pay for it all, allowing bus companies to inflate prices? Are there caps? If so, on what basis? And how does pricing work in a low-competition area like a subway operator with a 30y license, and government paying for it all?
Again, I'm a big fan and we need to move this forward. But I'm interested in what system they (and other cities that experiment with this) put in place to manage it all.
Either way, can't wait to see this arrive in my city. Working remotely, strong local walkable communities, ubiquitous public transport and automated ridesharing are strong candidates for the future, all of it electric and low-sound. That should increase traffic density, clean up cities from sound and pollution, make traffic safer and cheaper.
edit: another issue that comes up is demand-control. For example I currently have a 60-70% discount subscription but only if I travel outside of peak hours. That absolutely induces me to travel differently, e.g. leave home earlier or stay a bit longer at work or uni until I get my discount. Free public transport removes that instrument. There's a lot of talk nowadays about trying to change the 9 to 5 model to one that's spread out more. e.g. universities having an 11 to 7 model, some companies going 10 to 6. Part of that story is traffic management, and free public traffic throws out this instrument. It may also disincentivize cycling, to a small extent walking, and perhaps most importantly, wanting to live as close to the 'rest of the day' (work, school, friends) as possible to reduce costs.