7.—(1) The exterior of the train shall be fitted, on the front of the leading vehicle of the train, with a public address system for visual announcements which complies with the requirements in paragraph (2).
(2) The requirements are—
(a)the first letter of, and numbers used in, announcements made on the system shall be not less than 70 millimetres high, and all letters and numbers shall contrast with their background; and
(b)a word on the system shall not be written in capital letters only.
(3) Whilst the train is stationary at a station the system shall be used to announce the destination of the train, or, if the train is following a circular route, the name or number of the route.