One day, French President Gaston Doumergue mentioned to André Citroën and Georges-Marie Haardt that a regular rail link between the North African French colonies and Madagascar, a French territory isolated in the Indian Ocean, would be advantageous to France.
André Citroën organized the "Black Cruise", to survey rail routes, and no doubt, to publicise his automobile company. After 10 months of preparation, 8 Citroën half-tracks left the southern terminus of the Algerian Railway on 28 of October 1924. It appears that the half-tracks were based on Model "B" Citroëns.
The expedition was again led by the general manager from Citroën, Georges-Marie Haardt, and each half-track carried three men. A motion picture producer and a camera operator, an artist, a medical doctor who also took care of taxidermy, scientists, nine factory driver/mechanics, and other staff (some military) were on the expedition. http://www.practicalmachinist.com/vb/antique-machinery-history/ot-crawler-tractors-196276/index13.html
Georges-Marie Haardt authored a book about the second African trip (The Black Journey: Across Central Africa with the Citroën Expedition) and a National Geographic Magazine article in the June 1926 issue
So, it is a very long story, started by 1910 in St. Petersburg, where the Kégresse track was invented, continued in the twenties and thirties in Africa and Asia with the great Citroën expeditions, opening car routes across Sahara and on the Silk Road, immortalized in the two movies that were rediscovered by Jack Goelman in the fifties, then by the two German directors that created the documentary for ARTE in 2006, and finally published on youTube by the passionate Zagrebians from the Citroën Klub.
some info and the videos from http://updateslive.blogspot.com/2010/11/la-croisiere-noire-1926.html
in 1923-25 the Renault company was also trying to get publicity and accomplishments http://justacarguy.blogspot.com/2013/05/1923-1925-renault-10cv-type-mh-6x6.html
above from http://www.citroen.co.nz/citroen-universe/history/adventure/
To bring attention to his half-track vehicles launched in 1922, André Citroën organised a trans-Saharan expedition from 1922 to 1923. This success was followed by the Croisière Noire expedition, which crossed the African continent from north to south, travelling from Colomb-Béchar to Cape Town, between 1924 and 1925.
The Croisière Jaune expedition crossed Asia, from Beirut to Beijing, between 1931 and 1932.
Citroën subsequently supplied Admiral Byrd with three half-track vehicles for his Antartic expedition (1933 – 1935). It also supplied five vehicles for the Croisière Blanche expedition organised from July to October 1934 in the Rocky Mountains of Canada. http://justacarguy.blogspot.com/2009/12/failed-1934-expedition-acorss-canada-in.html
for a good over view of cross country pioneering motorists in Africa, see http://www.londoncapetownrally.com/history.html or http://www.andrewdenning.org/driving-into-darkness.html