This article lists anniversary events related to rail transport that occurred on April 4.

• 1909 – The Chicago, Lake Shore and South Bend Railroad (predecessor of the Chicago South Shore and South Bend Railroad) begins passenger train operations between Hammond, Indiana, and Pullman, Illinois.^[1]
• 1987 – The Soo Line Railroad announces the sale of its Lake States Transportation Division to private investors, forming the new Wisconsin Central Transportation Corporation.

• 2002 – General Motors Electro-Motive Division and Porterbrook are awarded a contract to build new diesel locomotives for the first open access rail freight carrier in Belgium.

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  2005 – East Japan Railway Company and Tokyo Waterfront Area Rapid Transit introduce women-only passenger cars in trains on the Saikyo and Rinkai Lines to deter groping.
• 2005 – The sale of General Motors Electro-Motive Division to Greenbriar Equity Group and Berkshire Partners is completed; the new company is known as Electro-Motive Diesel, Inc. (EMD).

• 1818 – Robert Pearson Brereton, chief assistant to Isambard Kingdom Brunel who completed many engineering projects after Brunel's death in 1859 (d. 1894).
• 1903 – Edward T. Reidy, president of Chicago Great Western Railway 1957-1968 (d. 1975).