March 28 – First services operate on Binhai Mass Transit (or Jinbin light rail) in Tianjin, China, including No. 1 bridge (25.8 kilometres (16 mi) in length).[2]
June – Caltrain finishes their two-year-long CTX project, which included strengthening the tracks between San Francisco and San Jose and introducing an all new CTC system. This project allowed for the start of Baby Bullet express service and the resumption of weekend service on the route.
June 7 – The high speed Gautrain between Johannesburg and Pretoria, South Africa is announced; it is expected to open in 2009.
July 29 – The Dublin to Rosslare Europort route becomes the first in the Irish Republic to have locomotive hauled trains completely replaced by diesel railcars.
August 15 – Fourth rail was finished in 13 km section between Helsinki, the capital of Finland and Kerava, its suburb.
August 31 – The United States Surface Transportation Board renews the authority of TTX Corporation to continue pooling and leasing railroad rolling stock for ten more years, over the protests of other rolling stock leasing companies.
September – In Ireland, following the replacement of the Cahir viaduct, the Limerick junction to Waterford section of railway reopens after nearly a year after the viaduct collapsed under a cement train.
October 14 – The Canadian Transportation Safety Board issues its final report on the CN accident of May 2, 2002; the report blames the truck driver's fatigue as the cause of the accident and admonishes fire crews for less-than-optimal training in hazardous materials.
October 15 – Canadian National Railway announces that it is selling its locomotive remote control business unit (which produced the Beltpack control system) to Cattron Group, Inc., so the railroad can focus on operations.
October 22 – Canadian National Railway (CN) announces that it will open shipping offices in Shanghai and Beijing; the office will advertise CN's shipping abilities to North American destinations, especially on the Pacific coast.
Siemens receives an order to build 60 new ICE trainsets for service between Moscow and Saint Petersburg, Russia; the new equipment is expected to enter service in 2007.
April 22 – In the Ryongchon disaster, a flammable cargo explodes at the railway station in the town of Ryongchŏn, North Korea, near the border with China; the explosion occurs only a few hours after North Korean leader Kim Jong-il passed through the station en route back to the capital from a secret meeting in China.
May 19 – Two BNSF Railway rock trains (#6351 north and #6789 south) collide near Gunter, Texas, killing one person and seriously injuring tjree others. The cause was the southbound train not stopping at its assigned stopping point for reasons unknown.
May 31 – A fire erupts in one of the Seattle Center Monorail trains; of the 150 passengers aboard at the time, only 5 required treatment for minor injuries and no deaths occurred.
June 17 – The Karanjadi train crash was the accidental derailment of a passenger train at Karanjadi, a village in Maharashtra, India, on June 17, 2004. 20 people were killed and well over 100 injured in the crash, which was the result of heavy monsoon rains.
October 23 – The Chūetsu earthquake, 6.8 magnitude, in Japan causes the first derailment of a Shinkansen train; the train was traveling 200 km/h (125 mph) on the Tokyo-Niigata line, but no fatalities were reported.
