Is it illegal to reverse from a side road to a main road?

[handpaper]

7mike said:

Anyone who drives LGVs / PCVs deals with this sort of thing pretty much on a daily basis. Drivers who can not / will not read the road and who have bugger all ability to judge space. Having dug themselves into a hole, it is everyone else's responsibility to sort it out for them. Occasionally, it dawns on these characters that it really will have to be them to do the backing up, and it can be quite painful to watch!

I do find it amusing that my line of work is described as 'manual'.
Driving large vehicles, particularly in town, is an exercise in situational and spatial awareness, with a little psychology thrown in. Thinking not just for yourself but for every muppet on the same bit of road gets tiring.*

• Not every driver is a muppet, they're just the memorable ones