I don't know if the concrete is going to be able to support the weigh of a single car anymore. They could repair the tracks, but beneath that is going to take a few weeks to get the rebar and concrete to cure over.

That is of course assuming no structural damage to the situation of a bombs striking it multiple times.

Though knowing russia, they will do some mental calculus and say something like, the risk of a single car derailing is worth the risk.