The alleged contravention is 38L,
Failing to comply with a sign indicating that vehicular traffic must pass to the specified side of the sign
But what does the Keep Left sign, diagram 610, actually mean? It's TSRGD 2016 Schedule 3 Part 4 Paragraph 3 (https://www.legislation.gov.uk/uksi/2016/362/schedule/3/part/4/paragraph/3/made):
(1) Except as provided in sub-paragraphs (2) to (5), the requirement conveyed by the sign is that vehicular traffic passing the sign must keep to the left of the sign where the arrow is pointed downwards to the left, or to the right of the sign where the arrow is pointed downwards to the right.
(2) Sub-paragraph (3) applies on an occasion where a vehicle is being used for at least one of the purposes set out in sub-paragraph (4) and the observance of the requirement in sub-paragraph (1) would be likely to hinder the use of the vehicle for that purpose.
(3) The requirement conveyed is that the vehicle must not proceed beyond the sign in such a manner or at such a time as to be likely to endanger any person.
(4) The purposes are—
(a) fire and rescue authority;
(b) Scottish Fire and Rescue Service;
(c) ambulance;
(d) blood service;
(e) providing a response to an emergency at the request of an NHS ambulance service;
(f) bomb or explosive disposal;
(g) special forces
(h) police; and
(i) National Crime Agency.
(5) The requirement in sub-paragraph (1) does not apply to a tramcar or trolley vehicle
Note that it doesn't say that Harrow council vehicles are allowed to pass the sign on the "wrong" side.
Now let's look at the TMO which applies to Charlton Road. This is The Harrow (Prescribed Route) (Width Restriction) Traffic Order 2007 (https://www.whatdotheyknow.com/request/harrow_width_restriction_tmos/response/2866464/attach/2/8814463%202007%2007%20AMND.pdf).
Article 3 and Column 4 of the Schedule impose a restriction of 6'6" on the lanes at either side of the road.
Between the traffic islands, Article 2 and column 3 of the Schedule specify the following restrictions:
2. No person shall cause any vehicle to proceed in a length of carriageway specified in columns 2 and 3 of the Schedule to this order.
. . .
4. Nothing in Articles 2 and 3 of this Order shall apply to :-
(a) any vehicle being used for ambulance, fire brigade or police purposes;
(b) anything done with the permission or at the direction of a police constable in uniform;
(c) any person who causes any vehicle to proceed in accordance with any restriction or requirement indicated by traffic signs placed pursuant to section 66 or section 67 of the Road Traffic Regulation Act 1984;
(d) any vehicle specified in column 6 of the Schedule to this Order;
(e) to any vehicle being lawfully used in connection with the maintenance of public services maintained by the London Borough of Harrow. [LBH2012/30]
Note in particular article 4(e). This permits vehicles which are
being lawfully used in connection with the maintenance of public services in Harrow to use the "Prohibited length". But we have seen that TSRGD 2016 Schedule 3 Part 4 Paragraph 3 does not exempt such vehicles from the requirement to pass on the "correct" side of the diagram 610.
It follows that vehicles on Harrow Council business, e.g. rubbish collection, are
not being lawfully used when they pass between the traffic islands. There is therefore no difference in law between my passage between the traffic islands and that by vehicles delivering pubic services for Harrow Council.
While Civil Enforcement Officers administering Harrow's PCNs have discretion in whether to issue them, they are obliged to follow administrative law in doing so. A central principle of administrative law was stated by Lord Greene MR in Associated Provincial Picture Houses Ltd v Wednesbury Corporation (https://en.wikipedia.org/wiki/Associated_Provincial_Picture_Houses_Ltd_v_Wednesbury_Corporation):
a person entrusted with a discretion must, so to speak, direct himself properly in law. He must call his own attention to the matters which he is bound to consider. He must exclude from his consideration matters which are irrelevant to what he has to consider. If he does not obey those rules, he may truly be said, and often is said, to be acting "unreasonably."
An action which flouts this principle is liable to be quashed as "unreasonable". It becomes a nullity, i.e. it is as if it had never existed.
On Charlton Road, it appears that CEOs have taken account of irrelevant considerations, viz that there happens to be a TMO which appears to − but does not − exempt vehicles on Harrow Council business from using the lane between the traffic islands.
I submit that this action by the CEOs renders the issuing of a PCN to me
ultra vires and therefore null. What is sauce for the goose is sauce for the gander.
Of course, if Harrow Council complied with Regulation 18 of The Local Authorities’ Traffic Orders (Procedure) (England and Wales) Regulations 1996 (https://www.legislation.gov.uk/uksi/1996/2489/regulation/18) and placed signage which truly showed the effect of its TMO, this issue would not have arisen. There would be no diagram 610s on bollards on the left-hand traffic islands as some vehicles (other than the emergency services and related ones) are permitted to pass to the right of those traffic islands. I submit that the correct way to sign the TMO is to place appropriate signs on posts on both traffic islands to show which vehicles are permitted to pass between them.