Since he began working on China's rail network in 1985, Xue Jun has earned seven train driver's licenses. Over the past 30 years, Xue has driven trains powered by steam, diesel and electricity, including diesel multiple units and bullet trains, and witnessed speeds rise from 60 kilometers an hour to 350.

The 50-year-old, who drives bullet trains for the Jinan Railway Bureau in the capital of Shandong province, was elated when he sat in the driver's cabin for the first time in 2011.

"I felt proud of myself for earning a license to drive such an amazing train, and proud of my country for developing the infrastructure so rapidly," he said.

He remembers his first encounter with the railway when he traveled on an old-fashioned steam locomotive with green livery, the type that disappeared from China's tracks long ago. "It was about an eight-hour journey but the cars were so full of people there wasn't even a small area of floor to sit on. I stood for the entire journey," he said.

Growing up near a railway line, Xue often watched the giant vehicles rushing by and thought it would be exciting to drive one. Eventually, his wish came true. During his training, the teacher told the students that after 2000, all trains would be powered by electricity, would be equipped with air conditioners and would not emit pollutants.

"We found that impossible to believe," he said.

Xue started as a fireman, shoveling coal into the locomotive's firebox - after every 12-hour shift, his face, hands and clothes were covered with coal dust. However, when he gained a train driver's license in 1987, he found the job was just as hard as being a fireman.

"The locomotive always shook greatly and swayed from side to side. We had no safety monitoring systems, and most drivers relied on observing rocks on the adjoining road to guess their speed."

When intercity multiple unit trains began operating in 2008, Xue had a glimpse of one as it dashed by when he was driving an old electric locomotive.

"Now, I only have a vague memory of its appearance. At the time, I was just stunned by the speed, and determined to get a license."

The days when he got dirty and fought to stand upright in a locomotive have long gone. His bullet train is equipped with a comfortable cabin that contains a refrigerator, a microwave oven, a heater and an air conditioner. Advanced safety devices are fitted during construction, so people can enjoy safe, quick and smooth journeys.

"People nowadays have a growing need for travel, and all the convenience and comfort they experience are largely due to 40 years of technological developments," he said.