Seventy-two cars have set off from Russia's north-western port of Murmansk for what is being billed as the world's longest winter rally.
The rally is being held in treacherous conditions
They are aiming to cross Russia in two weeks, finishing the Expedition Trophy race in the eastern port of Vladivostok some 12,000 km (7,456 miles) away.
The winner will receive 10kg (22lb) of gold, reports say.
The race follows the opening last year of the trans-Siberian highway - the longest road in a single country.
The highway from St Petersburg to Vladivostok spans some 10,500km (6,524 miles).
The 36 teams - each consisting of two cars - will compete over seven stages, with several losers eliminated at the end of each stage.
On the rally's last leg from Khabarovsk to Vladivostok only seven teams will be left.
The contestants range from amateurs to corporate-backed teams from Russia, Ukraine, Latvia, Germany and the US.
And they're off... icy surfaces await the drivers
They set off on Wednesday from a lighthouse near Murmansk and were expected later in the day near St Petersburg - where the race would begin in earnest.
The rally is being promoted under the slogan "There are enough roads for everyone".
But in reality, contestants will face thousands of kilometres of little more than gravel and ice on their way to Vladivostok.
"It is a road in the loosest sense of the word," Alexander Kravtsov, one of the organisers of the rally, was quoted as saying by Russia's The St Petersburg Times newspaper.
A special train - with reporters and celebrities - will accompany the rally. A huge concert is planned on a frozen lake when the competitors reach the city of Irkutsk.
The race dwarfs the 7,821km-long (4,860 miles) Trans-Canada Highway and America's Route 66 from Chicago to Los Angeles, which spans for 3,862km (2,400 miles).