Thanks to tight restrictions aimed at stopping the spread of COVID-19, foreign athletes, media staffers and officials at the Beijing Winter Olympics will only glimpse everyday life in China from inside the so-called closed loop management system separating them from local residents. While the Olympic exclusion zone is essentially limited to sports venues, press centers and accommodation, it also affords some visitors a close-up look at one of the most visible symbols of China’s growing economic power — the country’s high-speed railway network. The main Olympic hub in central Beijing is connec…