Why is there not any actual clear and correct procedure for 'blind' or part obscured junctions where yellow boxes are enforced

I use a local road almost daily which is a junction crossover with a key trunk 'A' road with a flyover above. East/West. The junction has a yellow box split in the middle North/ South and is primarily to keep the North/ South route clear from the much heavier traffic of the 'A' road.

Recently, there have been roadworks to the flyover and the roads below have been affected with a few changes of use of the junction.

On the last occasion, the junction was altered overnight to a complete blockade North/South. Using unmarked dark concrete barriers. No signage or advance warning had been installed, but all southbound traffic was diverted left. The traffic signals remained in use with no filters.

However, the diversion signage and associated equipment was placed on the pavement on the left of the road, awaiting positioning ( two days later) but completely obscuring an already part obscured junction to the the left.

The line at the traffic lights is set back slightly so when green you have to proceed looking both ways for a still live two way cycle route and then into the junction which is still part obscured. It is not possible to see the traffic ahead until fully into the yellow box.

Needless to say the Yellow Box has been fully enforced and the response quotes refer only to the Highway Code and right turns.

The roadworks ( now in the 5th month ) is dismissed as irrelevant even though the junction for which the yellow grid is in place is not functional and the roadworks also responsible for sudden stoppages by plant and workers but not at all visible to traffic turning into the road from the north.

There appears to be no actual reference for procedure to turn left into a Yellow Box junction in particular when it it is not possible to see if the full extent of the exit is clear.

Drivers do not have the advantage of a 30 ft high camera angle but if in a lower conventional car have walls, shrubbery and street furniture to see through.

The cameras do no show the effect of the obscured view or the road far enough clear of the grid to show what causes sudden stoppages of a normally free flowing road east.

So why is there not any actual clear and correct procedure for 'blind' or part obscured junctions where yellow boxes are enforced.

There appears to be absolutely nothing in the Highway Code that refers to such scenarios.

Yet this is being a fully enforced offence with a rationale of justification based on using a Yellow Box right turn as quoted from the Highway Code.

It needs addressing and amending with a clear procedure.