The alternative is generally some form of ballastless or slab track – https://en.m.wikipedia.org/wiki/Ballastless_track https://en.m.wikipedia.org/wiki/Ballastl

The alternative is generally some form of ballastless or slab track – https://en.m.wikipedia.org/wiki/Ballastless_track https://en.m.wikipedia.org/wiki/Ballastless_track - essentially rail fixed directly to a concrete substrate using a variety of different approaches. Lower maintainance costs at the expense of higher installation costs, and most often seen on high-speed systems, tunnels etc. There are also various forms of baulk track – https://en.m.wikipedia.org/wiki/Baulk_road https://en.m.wikipedia.org/wiki/Baulk_road - in which the rails are supported longitudinally with regular tie-bars to maintain gauge. I don’t think this is used much outside of some specialist applications.