|(a) If a rail transit agency determines, or is notified
by the department, that the safety program plan needs to be modified,
the rail transit agency shall submit the modified plan and any subsequently
modified procedures to the department for review and approval.
(b) Except as provided by subsection (c) of this section,
the rail transit agency may not implement the proposed modifications
before the modified plan is approved by the department.
(c) If the rail transit agency determines that a modification
is necessary to address an imminent safety hazard, the rail transit
agency may make a temporary modification to its system safety program
plan before that modification is approved by the department, but the
modification must be approved by the department before it may become