Awesome look behind the scenes....
https://www.bbc.com/news/entertainment-arts-47827316So here was the challenge, taken up by the teams (five started the race, and six pairs took part in all - but one team had to be replaced in the first episode due to a family emergency, and one was eliminated at the second checkpoint):
◾They had to travel the 12,000 or so miles overland - Singapore being chosen as it's the further place from the UK you can get to by rail and road
◾They were given: a world map; money belts containing £1,329 in pounds sterling each; a GPS device to track their progress; a travel guide with local job ads, so they could top up their cash along the way
◾The first team to arrive in Singapore would get a £20,000 prize to share
◾Each team had two members of the film crew embedded with them, but they had no say in any of the decisions