After reaching Ouagadougou, the next stage of their journey would have seen them head to a reforestation project in Togo, which is considered safer by GAC. But getting there overland would have required a journey through another red zone in southern Burkina Faso. ("Avoid all travel to 40 km within borders of Benin and Togo due to the threat of banditry and terrorism.")
Travel dates back to antiquity where wealthy Greeks and Romans would travel for leisure to their summer homes and villas in cities such as Pompeii and Baiae. While early travel tended to be slower, more dangerous, and more dominated by trade and migration, cultural and technological advances over many years have tended to mean that travel has become easier and more accessible. Mankind has come a long way in transportation since Christopher Columbus sailed to the new world from Spain in 1492, an expedition which took over 10 weeks to arrive at the final destination; to the 21st century where aircraft allow travel from Spain to the United States overnight.