Some roads and regions are known to be difficult to cross, if at all, because of poor terrain or because of complex administrative or unstable political conditions. This list below is only indicative of the global situation and is available to the community of riders to update. Also, the US Department of State offers some up-to-date information about country-specific travel conditions and warnings.
Central Africa - The many civil wars in Eastern Democratic Republic of Congo and Rwanda since the mid-1990s, as well as involvement from Uganda, has made tourism and travel through this region difficult and unsafe. However, several travelers still ride through the region.
The Horn peninsula - This region is currently one of the riskiest area in terms of political instability. Although Ethiopia remains a accessible, Somalia, which has been under a state of civil war and lawlessness for the last two decades, is definitely a no-go zone for tourism.
Sahel (Southern Algeria, Niger, Chad, Mali, and Mauritania) - The entire Saharan region called Sahel, stretching from the Mauritanian Atlantic coast to Chad and from Southern Algeria to Northern Mali is politically unstable and terrorism activities and recent kidnapping and killing of Westerners has made it almost a no-go zone. Tensions rose so much over the last 5 years that even the Dakar Rally organization decided in 2008 to move the entire rally raid to South America.
Dakar to Bamako - In addition to the political tensions in the entire Sahel region, the road between Dakar (Senegal) and Bamako (Mali) is extremely difficult going through rough terrain. Going East, conditions worsen starting from Tambacounda in Eastern Senegal and don't clear up until Kayes in Western Mali. An alternative is to use the Dakar-Bamako train, although this also remains a adventure in itself. These conditions force the rider who do not want to engage on this road but wishes to continue onto Africa to chose the West African coastal road or the Northwest African coastal road onto Mauritania and Morocco, although both are marked by significant political instability. The other option is to ship the motorcycle out from Dakar to another destination in Africa or South America.
Zimbabwe - The country's current regime has made tourism and travel in the country extremely risky since the late 1990s. There are however alterne routes bypassing the country, through Zambia, Botswana, or Mozambique, for the trans-African rider.
Iran - Iran has been unanimously described by riders as a great place to tour by motorcycle because of the sheer beauty of the landscapes, the richness of a 3,500 years old culture, and the very welcoming people. This said, recent escalation in tension between Iran's government and Western countries has made the country riskier to travel through.
Pakistan - Aside from the Karakoram Highway (see this entry above) which is still ridden, Pakistan has traditionally not been a place for motorcycle riding. Tensions in the region bordering Afghanistan and in Kashmir and frequent acts of terrorism as well as the scarcity of road linking the country to its neighbor countries doesn't make Pakistan a reasonably safe and practical destination for motorcycle riding.
The Amur Highway (between Chita and Birobidzhan, Russia) Some rough terrain on the Amur Highway, between Chita and Birobidzhan (2004) - The 2,100 km (1,300 mi.) long road is a combination of asphalt recently laid down and poor terrain that range from deep gravel to dirt and broken bridge. Traffic is regular, especially from spring to fall, and assistance can always be found from local drivers. The road is supposed to be fully covered with asphalt as of August 2010[1].
The Road of Bones (in Northeastern Siberia) - Branching off the Amur Highway, near Never, the 4,000 km (2,600 mi.) long road heads Northeast through Yakutia, a vast expense of land covered with thick taiga, to reach the Pacific ocean port of Magadan. The unpaved road is known to be extremely difficult with featuring dirt, gravel, and collapsed bridges and has remained a major challenge for motorcyclists, few having succeeded in riding it all the way through.
North Korea - The country is obviously unreachable, especially since the mid-2000s, when international tensions with Western countries, Japan, and South Korea about the communist regime's nuclear weapon program reached a peak. It is unheard of any motorcyclist having traveled through North Korea.
China - The only real difficulty in China is that the rider must get a local driver's license. The task is definitely feasible but requires a bit of time and logistics.
Mongolia - The country is a paradise for motorcyclist who love open spaces and who want to share the life of the locals horseback riders. The first difficulty to reach Mongolia, either from China or Russia, is the time it takes to obtain from the local consulates the proper documentation for independent motorcycle riding. A typical unpaved countryside road in central Mongolia (2004) The second difficulty is the poor quality of the road outside of the capital Ulaanbaatar, although most can be handled by a motorcycle. The third difficulty is the vast distance between towns and even between yurts, and the very low traffic on the roads, making assistance extremely scarce if needed for a technical or medical emergency.
Burma - The country is practical because it can link Eastern India with China and Thailand, thus helping making the Southern Asian road more continuous. The country is, however, a communist dictatorship which means that independent travel, particularly with a motorcycle, will require complex administrative processing.
Pacific Islands - The main problem with riding on the Pacific islands (Polynesia, Micronesia, Melanesia) is that the motorcycle must be shipped over to each island while the riding opportunities remain limited due to the small size of the islands.
Cuba - Like for any island, the motorcycle needs to be shipped over which adds to the trip's cost and logistics. More, citizens of the United States are officially not allowed to travel to Cuba, although this restriction is only enforced on the US side.
The Darién Gap (Panama/Colombia) - The Darién Gap is a large swath of undeveloped swampland and forest separating Panama's Darién Province in Central America from Colombia in South America. It measures just over 160 km (99 mi.) long and about 50 km (31 mi.) wide. Road building through this area is expensive, and the environmental toll is steep. Political consensus in favor of road construction has not emerged, and consequently there is no road connection through the Darién Gap connecting North/Central America with South America. It is therefore the missing link of the Pan-American Highway. Only a few riders have attempted to cross the gap and this multi-week long endeavor was met with incredible challenges, sometime having to haul the motorcycle with ropes, across swamps. The only way to bypass the gap is to ship the motorcycle by boat or airfreight from Panama to Columbia, Venezuela, or Ecuador.
Boa Vista to Manaus (Brazil) - The road allows going from Venezuela to Manaus. It is a difficult trans-Amazonian road, and pretty much the only one worth being labeled that way. Weather is definitely the main factor deciding on how difficult traveling will be. Daily showers can transform dirt roads into muddy marshes very difficult to cross.
Bolivia - Half of the country is at very high altitude in the Andes but many roads are in terrible conditions, especially in the South going through the Salar de Uyuni. The roads are also very sensitive to poor weather conditions.
Colombia - The country has been marred with guerilla and mafia activities for the last few decades with some foreigners, including a renown world-touring rider, being kidnapped. It seems, however, that recently travel is becoming more accessible. Many motorcyclist have traveled through Columbia over the last years, though, as the country is directly on the Pan-American Highway.
Reaching and riding in Antarctica - Cost of transportation and extremely limited riding opportunities are the main problems with riding in Antarctica. The only way to bring a motorcycle to Antarctica is to use one of the expensive cruise boats that sail from Southern Chile or Argentina to these countries' respective scientific bases on the iced continent. Once arrived, one can only ride around in the base assuming the iced or snow-covered ground allows for it. Not a practical choice but definitely a symbolic one fir the rider who wants to ride across all of the seven continents.
