I'll include the pertinent reasons as used in the case above
How?
In that case there was a single gateway sign and a so-called advance warning sign on the right-hand side of the carriageway adjacent to parking places. Now there's a pair of gateway signs and an 'advance' warning sign on the left.
I wonder whether you could you do something with the following:
While an advance sign is non-regulatory and therefore could comprise a sign or combination which is not prescribed, here the council have used the regulatory form of the sign with an associated plate. As this prohibition could be marked with a single sign, then a motorist could think that this was the start of the prohibition and because no sign preceded it still be cursing their luck and seeking to manoeuvre their car safely through the chicane when they come across a second set(which according to the council's video marks the actual start of the prohibition) and be unable to avoid. The council might argue that a motorist should not be misled because the 'associated plate' states ** ahead(OP, why is this out of focus, it's important).
But the regs do not permit such an associated plate to carry wording to the effect that 'the restriction doesn't start here, it starts in ***m and this is just a warning'! The only permitted plates relate to times and exceptions, but without exception when used in its regulatory form it carries only one meaning: the prohibition starts here.
Some thoughts.
Thanks for this, I'm aware in that case there was only one restriction sign, but the positioning is the same, which means it's still too late to do anything about it before you've entered the restriction because it's on / after a traffic calming / pedestrian crossing island.
Your point regarding the non-regulatory advance sign is very useful, and I think it (or something similar) is mentioned by the adjudicator in that case. I'm not sure why the sign appears out of focus for you, zoomed in you should be able to see it states "25 yds ahead".
The pertinent reasons I was referring to were :
"I find the nature of the location detracts from the restriction since it encourages motorists to construe the location as a traffic calmed crossing and thereby inducing the notion that traffic will be proceeding in order to be calmed"
"the central island prevents motorists from adopting a turn to effect a remedial manoeuvre in order to avoid transgressing the sign"
"The sign is placed at the end of the traffic island and, in my judgement, is unlikely to be seen by the motorist until they have entered the island
carriageway by which time there is no means of avoiding entry into the prohibited route.
"The motorist's attention on the approach is likely to be on the island sign directing traffic to bear to the left of the sign."
I will also mention two other sign related issues hopefully illustrated by photos below. 1) When approaching from Longhurst Road (the road to the right on the initial photos) there are two blue advance warning signs on a sharpish left hand corner just before the junction with Leahurst Road. The nearside one is obscured by a hedge, the far side one is right over in the other side, and there are numerous parked vehicles. A motorist should be concentrating on negotiating the corner and avoiding traffic coming in the opposite direction at that point rather than spotting signs. 2) When reaching the junction with Leahurst Road (to turn right) the small advance warning sign on the opposite side of the road is side on, and therefore impossible to read. So the first time you would be aware of the restriction is when confronted by the signs on the traffic calming island, which as mentioned above has it's issues.
I think I'm right in saying that previous Tribunal outcomes are not used as precedents? So the real question is what chance is there of success for this case, either with the evidence above, or with possible admin mistakes etc?


