My understanding is that trams are much more cost effective long-term than buses, because the rails last much much longer than asphalt or even concrete.
They also have other benefits:
Smoother, less bumpy ride
Bigger capacity than buses, with the possibility to add up to 5 cars
Don’t have to wait at traffic lights (We can install sensors to detect a tram is coming and switch the light so that it can go ahead without waiting. That’s technically doable for an BRT/SRB, but it’s more complex and as you can see, they didn’t do it for SRB Pie-IX…🙁)
Less noisy
Easier to electrify
Easier to automate (make them self-driving)
No tires means less pollution
Grass can be added between the 2 rails, making it more pleasant looking, absorbing heat and noise
My understanding is that trams are much more cost effective long-term than buses, because the rails last much much longer than asphalt or even concrete.
They also have other benefits:
You can see this thread for more benefits: https://www.reddit.com/r/notjustbikes/comments/qftru7/why_trams_and_trains_over_buses/