Melbourne (Australia, not Florida) still runs its train control system on a PDP-11.

equicon.de/images/Virtualisierung/LegacyTrainControlSystemStabilization.pdf

On an emulator, but nevertheless.

>In this particular train control application it has enabled the life extension of mature train control software, originally designed to run on a now life expired DEC PDP-11 platform to be migrated to a PC based platform. [...] Consequently, the major part of the project was the ‘hardware adaptation’ that was required to integrate the new system into the existing fabric.