There are many combinations in Kundali which help in traveling abroad.Rahu in the 4th house makes a person travel abroad. the 4th house indicates the residence or home of a native. Rahu in 4th makes it difficult to settle in your home town.  This happens true if Rahu Dasha also running. Since Rahu Dasha runs for 18 years after some hurdles finally Rahu causes a change of place also known as sthan dosh in  antardasha of Rahu or Ketu or  planets aspecting 4th house