The summary that follows was supplied by Jordi Pons, Barcelona, who took part in the expedition.
In July and August 2005 we measured the heights of those until now considered Highest Motorable passes in the world. The measurements were taken with GPS Leica GS20 and we can safely confirm that Semo la, a pass in Tibet, is 5565m high.
Khardung La, a pass through the Indian Himalaya north of Leh, Ladakh, considered until now the highest rideable pass in the world, and by Guinness World Records to be the highest accessible pass for vehicles, is 5359m high, not 5602m, as officially stated, or 5682m as still stated by some authorities. The measurements of the pass, recorded in GPS Leica GS20, have been postprocessed and recalculated by Leica Geosystem, the Cartographic Institute of Catalonia and Instituto Geografico Nacional (Spain).
We hope that the difference of more than 200m that we have found between both passes will be recognised by Guinness World Records. One of the problems to reach the Semo la pass is its height. Another big problem is the isolation of the place: the roads are in poor condition, there are hardly any villages and it is really difficult to find supplies, shelter, spare parts. In addition to this, the traveller has to get along with the lake salty waters... those who want to repeat the experience will need a considerable amount of time to recover their strength.
We encourage people to continue the research, and we will collaborate with those who take part in it, also we’d like to see the quest for other possible highest passes in Asia or in South America.
In the next issues of the "Vèrtex" and "El Mundo de la Mountain Bike" magazines, more detailed information will be included.
The road Leh to Khardung La is 37 km (more or less, because there are different routes from Leh to the start the road). It's paved and easy for 24 km, up to a check point, although the action in winter of ice, snow and the water in summer has broken up much of the paving. The Khardung pass summit is dirt. There is no paving for the last 13 km on the Leh side, or on the Nubra side. There are narrow and dangerous steps, and crossing rivers. It is ok for trucks and four wheels, but too bad for normal cars.
Is Semo motorable? Yes. There are no crossing rivers, or dangerous steps. The road is dirt, not paved, but it is wide. Workers repair the road. We saw trucks. There is a once weekly bus.
The profile in both passes is slow and similar 4%, 3%, 4% etc.
Frankly, if I were a truck driver I would prefer the Semo pass.