Humanitarian corridors have been used since the mid-20th century. During the so-called Kindertransport from 1938 to 1939, Jewish children were evacuated to the UK from areas under Nazi control. They were also created during the siege of Sarajevo, Bosnia, in the 1990s and the 2018 evacuation of Ghouta, Syria.
Article source: https://www.huffingtonpost.co.uk/entry/humanitarian-corridors-ukraine-russia_uk_62262826e4b012a2628e6912