If you think about it vehicles on asphalt/tyres (not buses as we know them) are superior to vehicles on tracks/steel wheels in every way (except rolling resistance). Vehicle to vehicle dista CE on the road can be as little as a few seconds, where on train tracks it is usually one to several minutes. Deadweight per passenger is in the range of 5-10x more for trainers vs buses. If a train breaks down, everything is blocked, on the road you just pull over and let others pass. I like to think that passenger rail is just an artifact of history/sunken cost phallacy, except maybe for underground high volume metro systems.

When looking over the vast 20 or so track wide rail intersection with multiple fly overs at Utrecht Central Station easily a minute can go by with not a single train passing, even in rush hour. And this is the busiest train station in the Netherlands. There is also a bus platform underneath which in a fraction of the space fits perhaps 20 (much smaller though) bus platforms.buses come and go continuously, largely over a single (two way) dedicated bus lane. This single road probably has a similar capacity as the twenty or so train tracks above, with extra long buses going by with minimal space between. If we were to pave the railway tracks we could have an incredibly safe and reliable transport system. Its actually quite a thing buses are already quite safe even though drivers make to long hours, share the road with many kinds of vehicles with mostly amateur (as in non professional) drivers, no central traffic control etc. Of course buses as we know it are not pleasant modes of transport, but that is probably only because they can also run on normal roads with sharp turns and traffic lights etc. I don't have the numbers to do a proper comparison but I think paving railroads could be quite an interesting business case