Authorisations for unusual signs in Cambridge

Dear Sir or Madam,

This request is a follow-up to
<http://www.whatdotheyknow.com/request/au...>
(your reference FOI/ECS/127430).

Please could you tell me whether each of the traffic signs in
Cambridge listed below either have been specially authorised by the
Secretary of State for Transport (or a predecessor) or are placed
in accordance with a special direction issued by the Secretary of
State (or a predecessor), as described in paragraph 2.1 of chapter
3 of the Traffic Signs Manual?

If any of the signs are the subject of such authorisations or
special directions, please could you send me a copy of the text of
the authorisations and special directions in question.

The signs in question are:

1: the curved circular blue sign with a white pedal cycle symbol
and a white arrow on Senate House Hill outside Great St Mary's
Church,

2: the circular blue sign with a white pedal cycle symbol and a
white arrow at the junction of Market Street and Sidney Street,

3: the circular blue sign with a white pedal cycle symbol, a white
motorcycle symbol and a blue arrow at the junction of Malcolm
Street and King Street.

Yours faithfully,

Ben Harris