Changes requiring filing of application.

(a) Except as provided in § 235.7, applications shall be filed to cover the following: (1) The discontinuance of a block signal system, interlocking, traffic control system, automatic train stop, train control, or cab signal system or other similar appliance or device; (2) The decrease of the limits of a block signal system, interlocking, traffic control system, automatic train stop, train control, or cab signal system; or (3) The modification of a block signal system, interlocking, traffic control system, automatic train stop, train control, or cab signal system. (b) [Reserved] (Approved by the Office of Management and Budget under control number 2130-0042)