I guess you mean quadrupole (+potential higher order) magnets? Long linear accelerators do this as well. They just keep the beam together, they don't reduce the emittance (like damping rings do for electrons), but the LHC doesn't reduce that either. 500 km through the Alps to replace about 35 km of LHC plus preaccelerators, built at convenient spots near Lake Geneva? Even if the tunnels would be wide enough to be used for transport afterwards (they are not), and even if there would be demand for a 500 km tunnel, that project would be way too expensive for particle physics or transportation. And that is just the tunnel - you need 500 km of accelerating structures. There is absolutely no way to fund that.