FOREIGN TRAVELERS WILL BENEFIT from a ``Currency Pak'' available to participants on any Trafalgar Tour. For $100 participants get enough local currency to get started in each country included in the itinerary. For details call (212) 319-6770. THE AMERICAN AUTOMOBILE ASSOCIATION has called for more-stringent standards for trucks to encourage safety on highways. Measures include enforcement of truck driver testing and licensing, stiff fines for violations of safety regulations, tougher standards for brakes and bumpers, and requiring of splash guards. BOSTON-LUXEMBOURG INSTANT FALL FARES will drop to $398 round trip from Sept. 8 through Sept. 30, to $378 in October, and then to $348 from Nov. 1 to Dec. 14. This includes a stay of 7 to 30 days abroad, with a stopover in Iceland. Purchase tickets through a travel agent or Icelandair, 800-223-5500. THE US STATE DEPARTMENT regularly prints foreign-travel advisories citing conditions that make travel difficult or unsafe. To check on a specific country or to ask for a series of pamphlets called ``Tips for Travelers,'' write to Citizens Emergency Center, Bureau of Consular Affairs, Room 4811, NS, US Department of State, Washington, DC 20520.