Summary: This document provides the public with notice that, on November 11, 2022, CSX Transportation (CSX) submitted an updated request for amendment (RFA) to its FRA-approved Positive Train Control Safety Plan (PTCSP). As this RFA may involve a request for FRA's approval of proposed material modifications to an FRA-certified positive train control (PTC) system, FRA is publishing this notice and inviting public comment on the railroad's RFA to its PTCSP.