the 1970s, the speed was increased further. In 1986, the travel time was 16 hours, 59 minutes. China introduced six line schedule reductions from 1997 to 2007. In October 2001, train T13/T14 took about 14 hours from Beijing to Shanghai. On April 18, 2004, Z-series trains were introduced. The trip time was cut to 11 hours, 58 minutes. There were five trains departing around 7 pm every day, each 7 minutes apart, arriving at their destination the next morning. The railway was completely electrified in 2006. On April 18, 2007, the new CRH bullet train was introduced on the upgraded railway as part of the Sixth Railway Speed-Up Campaign. A day-time train D31 served the route, departing from Beijing at 10:50 every morning, and arriving at Shanghai at 20:49 in the evening, travelling mostly at (up to in a very short section between Anting and Shanghai West). In 2008 overnight sleeper CRH trains were introduced, replacing the locomotive-hauled Z sleeper trains. With a new high-speed intercity line opening between Nanjing and Shanghai in the summer of 2010, the sleeper trains made use of the high-speed line in the Shanghai–Nanjing section, travelling at for a longer distance. The fastest sleeper trains took 9 hours, 49 minutes, with four intermediate stops, at an average speed of . As the Nanjing Yangtze Bridge connected the two sections of the railway into a continuous line, the entire railway between Beijing and Shanghai was renamed the Jinghu Railway, with Jing (京) being the standard Chinese abbreviation for Beijing, and Hu (沪), short for Shanghai. The Jinghu Railway has served as China's busiest railway for nearly a century. Due to rapid growth in passenger and freight traffic in the last 20 years, this line has reached and surpassed capacity. Dedicated high-speed rail proposal The Jinghu high-speed railway was proposed in the early 1990s, because one quarter of the country's population lived along the existing Beijing-Shanghai rail line In December 1990, the Ministry of Railways submitted to the National People's Congress a proposal to build the Beijing–Shanghai high speed railway parallel to the existing Beijing–Shanghai railway line. In 1995, Premier Li Peng announced that work on the Beijing–Shanghai high-speed railway would begin in the 9th Five Year Plan (1996–2000). The Ministry's initial design for the high-speed rail line was completed, and a report was submitted for state approval in June 1998. The construction plan was set in