Action
Notice of availability and request for comments.
Summary
This document provides the public with notice that, on July 25, 2025, 21 host railroads submitted a joint request for amendment (RFA) to their FRA-approved Positive Train Control Safety Plans (PTCSP) to implement onboard software Version 6.5.5.0, which would require modifications to the Interoperable Train Control (ITC) Positive Train Control (PTC) Concept of Operations and to the human-machine interface (HMI). As this joint RFA may involve requests for FRA's approval of proposed material modifications to FRA-certified PTC systems, FRA is publishing this notice and inviting public comment on the railroads' joint RFA to their PTCSPs.