The Zilov Gap was a 400 mile (640 km) roadless section in Central Siberia where there was no east-west road - the only communication was via the Trans-Siberian Railway

Trans-Siberian Railway

The Trans-Siberian Railway is a network of railways connecting Moscow with the Russian Far East and the Sea of Japan. It is the longest railway in the world...

. The Zilov Gap was a major challenge to long-distance overland expeditions and nearly caused the end of the Mondo Enduro

Mondo Enduro

Mondo Enduro was a round-the-world adventure motorcycle expedition in 1995-1996. Team members Austin Vince, Gerald Vince, Chas Penty, Bill Penty, Clive Greenhough, Nick Stubley and Mark Friend set off to go round the world by the longest route possible in the shortest time.Their route took them...

 expedition; the Long Way Round

Long Way Round

Long Way Round is a documentary television series, DVD set and book documenting the journey of Ewan McGregor and Charley Boorman from London to New York on motorcycles...

 trip avoided it altogether.

Notorious for the muddy terrain where 300 metres progress can take 3 hours and its numerous serious river crossings, the Zilov Gap was first crossed in 2000 by the Terra Circa

Terra Circa

The Mondo Enduro round the world motorbike expedition attempted but did not cross the Zilov Gap in Central Siberia. In 2000 a follow-up expedition, Terra Circa, was organised by Dave Greenhough, brother of one of the Mondo Enduro team members...

 expedition.

There is a well established road route round the north of Lake Baikal

Lake Baikal

Lake Baikal is the world's oldest at 30 million years old and deepest lake with an average depth of 744.4 metres.Located in the south of the Russian region of Siberia, between Irkutsk Oblast to the northwest and the Buryat Republic to the southeast, it is the most voluminous freshwater lake in the...

 which follows the Baikal Amur Mainline line.

There is a new road from Khabarovsk

Khabarovsk

Khabarovsk is the largest city and the administrative center of Khabarovsk Krai, Russia. It is located some from the Chinese border. It is the second largest city in the Russian Far East, after Vladivostok. The city became the administrative center of the Far Eastern Federal District of Russia...

 to Chita which was under construction in 2005, see article (with link to map in Russian) and photos. The remaining 2 km gap on the southern route was about to be filled in. The road was then used to export used cars from Japan.

Eastbound travellers on M58 highway (Russia)

M58 highway (Russia)

The Russian route M58 is a federal highway in Russia, part of the Trans-Siberian Highway. It runs from Chita to Khabarovsk and has a length of 2100 km....

 would load their cars onto cars of the Trans-Siberian Railroad at Chernyshevsk for the 800-km trip to Magdagachi

Magdagachi

Magdagachi is an urban-type settlement and the administrative center of the Magdagachi raion in Amur Oblast, Russia; population: 11,150 ; 12,208 ; 15,578...

(at least this was the case in 2001.). The Chernyshevsk-Magdachi gap is just north of the northernmost part of Manchuria.