Motorists desperate for a stunning road trip to tick off their bucket list may have Route 66, the Pan America Highway or the Stelvio pass among their top picks. 

However, the little-known Asian Highway 1 may top the lot with a 12,000-mile scramble over more than a dozen countries in less than a week. 

Dubbed the “gateway to Asia”, the route is the “longest road trip” across the continent and ticks dream destinations along the way. 

Starting in Istanbul, Turkey, the route will see motorists tick off the famous Danube River before heading East to Iran. 

Passing the capital Tehran, the map follows the north of the country before heading into Afghanistan, Pakistan and India. 

Drivers can head into Bangladesh before heading to Myanmar, Thailand and Cambodia. 

The next stretch heads across Vietnam,  Hong Kong and China before the final run passes through North Korea, South Korea and then into Tokyo, Japan. 

According to experts at Allianz, AH1 is likely to take motorists around 125 hours to complete. 

This means the whole journey can be completed in around five days if road users get a move on and don’t hang around. 

But, the specialists stress this isn’t the best way to see the sites and it is advised that holidaymakers take things a bit slower. 

Allianz instead claims visitors will want to allow around 4-6 weeks to take in the “magnificent treasures” along the way. 

Believe it or not, those travelling from Japan to Turkey can extend the trip well onto Europe for an extension to their trip.

It is possible to continue the route via the E80 which will lead drivers across to Lisbon in Portugal. 

Those not looking to drive can still explore a part of the route through a 2,800-mile bus trip from India to Singapore.

The journey will head through Myanmar, Thailand and Malaysia with around 20 passenger capacity for the three-week journey. 

However, AH1 is just one part of the much larger Asian Highway Network, a series of 87 different routes criss-crossing across the continent. 

The next largest is the AH2 road which is made up of over 8,000 miles from Denpasar in Indonesia to Khosravi in Iran. 

AH2 runs through a further 10 countries with drivers travelling through Indonesia, Singapore, Malaysia, Thailand, Myanmar, India, Bangladesh, Nepal, Pakistan and Iran.