Comedian Sue Perkins and adventurer Charley Boorman travel across Alaska to the notorious Dalton Highway - a dirt track built in the 1970s as a supply road to support the Trans-Alaska oil pipeline. As Arctic conditions close in on them, the pair have to rely on the help of hardcore truckers for whom the highway is home.

Comedians Rhod Gilbert and Greg Davies attempt to drive through the mountainous, landlocked nation of Nepal. Starting from the chaotic border with India, they travel across the country's most important roads, from highways that maintain its cities to freshly-dug dirt tracks that connect to isolated communities.

Adventurer Ben Fogle and comedian Hugh Dennis drive a historic route from the Peruvian Andes to the depths of the Amazon, along roads built to conquer and exploit the natural wealth of Peru's rainforest. It's a rollercoaster ride of 2,000 foot drops and hairpin bends on one-lane dirt roads. At the end of this epic journey they hope to find the lost city of Constitucion.

Good friends and fellow comedians Ed Byrne and Andy Parsons brave temperatures as low as minus fifty to drive across Siberia's infamous Road of Bones. Along the way they encounter all that Siberia can throw at them from terrifying roads of ice and deserted gulags, to the surprising welcome of the people who inhabit this freezing wilderness. Ed and Andy soon learn the rules of road in this remote region - never turn the car engine off and refuel on the go but the further they get along the road, the more they realize they are out of their depth.

Sue Perkins and Liza Tarbuck drive the legendary Ho Chi Minh Trail, a network of dangerous roads hacked through mountains and jungles of Laos and Vietnam. Its role in the Vietnam War has left it one of the most perilous roads in the world as it is littered with unexploded bombs. Sue and Liza face a gruelling drive to some of the least explored sections of the trail, with both terrifying and hilarious consequences.

Comedians Hugh Dennis and David Baddiel drive over 2,000km of Ethiopia's death-defying, bone-shaking roads in a quest to reach Aksum, known as the home of the Ark of the Covenant. Along the way they have to compete with truck drivers high on local drug khat, a calamitous breakdown and a shortage of fuel in the middle of the night. At times, it seems like David and Hugh will need a miracle to get them to the end of the road and the holiest place in this deeply religious country.