I think I've come up with the perfect plan.
Leg one: Seattle, Washington to Osaka, Japan (Starting point an island so that contestant row to mainland to drive to airport.)
Leg 2: Osaka, Japan to Manila, Philippines (NEL)
Leg 3: Manila, Philippines, to Ho Chi Minh City, Vietnam (With throwback Roadblock)
Leg 4: Ho Chi Minh City, Vietnam, to Antananarivo, Madagascar
Leg 5: Antananarvio, Madagascar, to Nairobi, Kenya (NEL)
Leg 6: Nairobi, Kenya
Leg 7: Nairobi, Kenya, to Athens, Greece
Leg 8: Athens, Greece, to Sofia, Bulgaria (Final NEL)
Leg 9: Sofia, Bulgaria, to Budapest, Hungary, to Vienna, Austria
Leg 10: Vienna, Austria, to Lisbon, Portugal
Leg 11: Lisbon, Portugal to Bridgetown, Barbados
Leg 12: Bridgetown, Barbados, to either New Orleans, Louisiana, or Miami, Florida
Sorry no South America