1940 in rail transport

January 9 – The Østfold Line in Norway takes electric traction into use between Ås and Dilling.^[1]
January 14 – Atchison, Topeka and Santa Fe Railway discontinues the San Francisco-Los Angeles-Chicago Navajo.
January 27 – The Boston, Revere Beach and Lynn Railroad ceases operations in Massachusetts in preparation for abandonment.
January 29 – Three gasoline-powered trains carrying factory workers crash and explode while approaching Ajikawaguchi Station, Yumesaki Line (Nishinari Line), Osaka, Japan, killing at least 181 people and injuring at least 92.

May 1 – The Østfold Line in Norway takes electric traction into use between Dilling and Fredrikstad.^[1]
May 20 – Sixty-six railroads in the United States, in cooperation with the Travelers' Credit Corporation, begin selling railroad tickets, Pullman accommodations and all-expense tours on an installment basis, known as the Travel Credit Plan. Purchases over $50 can be charged.

June 21 – East Wind begins summer service over the Pennsylvania, New Haven, Boston & Maine and Maine Central railroads between Washington, D.C., and Maine.^[2]
June 29 – Syracuse Transit Corporation closes the South Salina and Nedrow lines in Syracuse, New York.
June 30 – Last day archbar freight trucks can legally operate in U.S. Interchange service (and then only on empty cars returning to their home roads).
June – Chicago, Rock Island and Pacific Railroad takes delivery of the unique EMC AB6 locomotives.

July 1 – Portions of the SNCF in Alsace-Lorraine are incorporated into the Deutsche Reichsbahn.
July 15 – The Østfold Line in Norway takes electric traction into use between Fredrikstad and Sarpsborg.^[1]
July 17 – The last section of the Baghdad Railway's mainline linking Istanbul and Baghdad is completed between El Yaroubieh and Baiji^[3] and the Compagnie Internationale des Wagons-Lits' Taurus Express begins to run throughout between Haydarpaşa Terminal, Istanbul, and Baghdad Central Station.
July 29 – Rail traffic is suspended in France between French-retained and German-occupied territories.
July 30 – The Pennsylvania Railroad orders its first 4-4-4-4 T1 duplex-drive steam locomotives. They are expected to be serious competition for diesel power.

August 1 – Norwegian State Railways runs first through train on the Flåm Line.^[4]

October 1 – The Pennsylvania Turnpike opens, constructed using tunnels and grades originally built for the never-completed South Pennsylvania Railroad.

November 4 – Norton Fitzwarren, England: a train driver on the Great Western Railway misreads the signals on a four track line, and drives his train off the end of the track.
November 11
- The Østfold Line in Norway takes electric traction into use between Sarpsborg and Halden.^[1]
- Syracuse Transit Corporation closes the Elm Street line in Syracuse, New York.
November 22 – The Newark City Subway in New Jersey opens an extension from Heller Parkway to Grove Street.^[6]

December 15 – The IND Sixth Avenue Line of the New York City Subway is completed and opened throughout.
December 17 – The Florida East Coast Railway introduces the Dixie Flagler passenger train between Chicago, Illinois and Miami, Florida, replacing the Henry M. Flagler.

Events