I did compose an explanation, but must have forgotten to click the "comment button"

I got the speed limit boundary wrong because I was fixing it relative to the (now mapped) crossing island, rather than the bridge. I assumed that the crossing point had been mapped correctly.

So the speed limit signs and path crossing point have now been moved to the correct position - some way south of the bridge.

Thinking about it, the bridge should probably not be mapped as the canal is mapped as in a tunnel.
