I have just come across another, multi-country road design standard. It covers the Arab Mashreq International Road Network. Wikipedia says that :
The Arab Mashreq international Road Network is an international road network between the Arab countries of Syria, Iraq, Jordan, Palestine (Israel included), Lebanon, Kuwait, Egypt, Saudi Arabia, Bahrain, Qatar, UAE, Oman and Yemen.
The 2001 UN document (ref. 2135) on the “Agreement On International Roads In The Arab Mashreq” includes a table with technical specifications to be met on the links in this network, and other detailed notes on e.g. vertical clearance. Much of the table seems to be based on AASHTO specifications.
Most of the countries listed above have their own road design standards. They are not necessarily the same as (or worse than) the suggested design values in the UN Agreement.
2135 UN, Agreement On International Roads In The Arab Mashreq; 2001