wrote:

Now this I find interesting.

I understand obstacle clearance, but had no idea that runway markings
and taxiway spacing affects DA.

I can understand runway markings (although I thought they were
standard for precision approaches) but taxiway spacing?


Yes. It's an Airports standard, not a TERPs criteria. It's contained in the
airport design advisory circular.

The rationale is spacing for wingtips in low visibility for spacing. And, there
is the issue of avoiding back-taxi at Class E or G airports.