One reason is permanence. A bus route can change easily, a dedicated bus lane can become an everyone lane with a coat of paint. A rail line is much harder to ch

One reason is permanence. A bus route can change easily, a dedicated bus lane can become an everyone lane with a coat of paint. A rail line is much harder to change, for me this was a big factor in deciding where to buy an apartment. > Rail doesn't have this flexibility. Because trying to maximize the utilized capacity creates worse outcomes. If there is only service every 30 minutes at a slow time of day then less people will use it because it's less convenient, so demand slows more and services are cut further, etc. Induced demand (https://en.wikipedia.org/wiki/Induced_demand https://en.wikipedia.org/wiki/Induced_demand) operates on public transport as well as roads.