Mr Xu settles down in his usual seat on the "green train" to Tai'an and smiles.

There are much faster ways to get to Tai'an. A high-speed train could get him there in under an hour, whereas the old diesel-engine train with its trademark green carriages can take three times that long.

But Mr Xu doesn't mind the longer journey. "It is OK to take a walk on the train if my legs are numb, but I can't do that on high-speed trains or shuttle buses," he says.

The "green train" travels between Tai'an and Zibo, two cities in East China's Shandong province. The diesel-engine train, the last service of its kind still operating in Shandong, has been running since 1974. [Photo/wechat: taiandzwww]