Construction on an express railway linking Beijing and the northern city of Zhangjiakou is expected to begin in 2014 and be completed in 2017, a local official said on Monday. The 174-km-long line is a cutting-edge advantage for the two cities to bid for the 2022 Winter Olympics, according to Zhang Chunsheng, an official in charge of the bidding office in Zhangjiakou. The express railway will reduce travel time from around four hours to 40 minutes.