Realistically, there won't be enough damage to Tehachapi to cause more than brief traffic interruptions for inspection and possibly minor cleanup, much like for the minor rockslides reported on roads away from the epicentral area. It would need to be a disaster on the scale of 1952 before UP would look at reroute options, and the line's not close enough to the earthquakes for that.

Trona RR may be another story. It's much closer to the active faults, and the highway (Route 178) that roughly parallels it had some major damage. But it runs only when needed for industrial service to the old Manville plant at Searles Lake, which will probably be shut down for a while to take care of its own problems and those of its workers.