TOKYO -- Japanese logistics company Nippon Express will begin road tests of automated trucks with a Volvo subsidiary next month, a step toward addressing the industry's severe shortage of drivers.

Nippon Express and local Volvo unit UD Trucks will carry out the testing with the Hokuren Federation of Agricultural Cooperatives, headquartered in Hokkaido. The trials will start out in the northern Japanese island's town of Shari, along a stretch connecting a sugar plant of the co-op group to a processing line 1.3 km away.

The trucks will operate at level 4 automation, just one notch below full autonomy. This will mark the first test in Japan using trucks at that level, often described as "high automation." For Volvo -- the Swedish commercial-vehicle maker on the forefront of self-driving trucking technology, along with Germany's Daimler -- it will mark the first such test in Asia.

Japanese law allows only level 1 and 2 vehicles on public roads, since these levels of automation still require substantial driver involvement. Nippon Express' testing is exempt because it will be done on private land. A staffer will sit in the driver's seat to handle unforeseen obstacles, but the goal is for the vehicle to handle everything itself.

The Japanese trucking industry is strapped for personnel. There were 2.86 driver job openings this May per applicant, more than double the 1.35 ratio for the labor market as a whole.

As the national population grays, Japan will face a shortage of 240,000 truck drivers by 2027 due to such factors as mass retirements, according to Boston Consulting Group.

Testing of level 4 vehicles is already allowed on public roads in the U.S. Only this May did Japan make legal changes to permit level 3 driving as early as next year.

Hokkaido has been pitching itself as an ideal testing grounds for automated vehicles, thanks to its wide-open spaces as well as its snow, chilly weather and other environmental extremes. The prefecture is now home to the highest concentration of testing areas at 28. Apart from public roads, a portion of the testing is being carried out at sparsely attended driving schools and vacant ski slopes.