At the IHE Traffic Signs 2018 conference today, DfT speakers produced printed copies of these new chapters. They can now be ordered from TSO, but I couldn’t see them yet on the TSO website. PDFs (with hyperlinks) to follow in due course.
Chapter 1 has more emphasis on reducing sign clutter, as expected. But the biggest surprise is perhaps the reappearance of the water depth indicator for use at fords in Chapter 4, with the note that it now needs to be authorised by the relevant national authority.
Chapters 1 & 4 have appeared today on the TSO shop website to ‘pre-order’ with no publication date yet announced. However, they contradict that by saying they will be despatched within 1-2 days of ordering!