The real aim is to get this PCN cancelled on the ground that the restriction was not adequately signed, because if the restriction was not fairly conveyed before the point of entry, that undermines the alleged contravention and that is the issue Barnet and any independent adjudicator, meaning the tribunal decision-maker, will actually care about.
On what you have shown, that argument is arguable but not strong. The stills suggest only one pedestrian-zone entry sign on the left and it does look mounted high, which gives you something to work with. But your car also seems to approach it almost head-on on a 20 mph street, which hurts. The legal question is really whether the sign gave clear notice in time, not whether the layout could have been better. Official guidance says traffic authorities must make signing necessary, clear and unambiguous, and that a single terminal sign can be acceptable if clearly visible; it also says two signs may be needed where drivers might otherwise miss the sign before making a manoeuvre. Pedestrian-zone restrictions are conveyed by the zone entry sign itself.
So the best point is not simply "there was only one sign". By itself, that is weak. The better point is: on this particular approach, this single elevated left-side sign did not adequately convey the restriction in time for a safe and informed decision. The evidence that moves that argument is the full CCTV clip, driver's-eye photographs, and any dated material showing the sign was partly obscured, visually lost among other street furniture, or not readable until the vehicle was already committed. I am assuming the layout on the day matched the stills; if Barnet's own footage shows a clearer sightline, or a second sign, your prospects drop.
I would make representations, meaning a formal challenge to the council, within the discount period and keep it tight: the restriction was not adequately signed on this approach because there was only one elevated left-side entry sign, with no corresponding right-side reinforcement, and the restriction was not conveyed clearly enough in time. Ask for the full CCTV, the legal order creating the restriction, and the council's site photographs or sign schedule. Then ask yourself one hard question now: are you willing to risk the full £160 to run an arguable but not strong signage case to London Tribunals, or is keeping the chance of paying £80 the outcome you can live with? If Barnet rejects, the appeal window is 28 days from service of the rejection notice.
