Interestingly, ICAO have just issued a notice of proposed rule change that amends the criteria for ACN/PCN calcs. It affect Annex 14.
I'm not clever enough to give a link to it but if someone can I think it's very informative.
A big discussion within ICAO's Pavement Sub-Group has been the factor applied to the metric for 6 wheel bogeys (read 773) the Alpha factor. I think Boeing won.
If an airport wants to pin its pavements' resilience to load then a falling weight deflectometer might help. Just don't stand too close unless you want very flat wide feet
There's the 10% overload allowance too btw.
Sir George Cayley