Portal:Transport/Selected anniversaries/September 3
- 1878 – Over 640 die when the crowded pleasure boat Princess Alice collides with the Bywell Castle in the River Thames.
- 1967 – Dagen H (pictured) in Sweden: traffic changes from driving on the left to driving on the right overnight.
- 1976 – Viking program: The Viking 2 spacecraft lands at Utopia Planitia on Mars.
- 1997 – A Vietnam Airlines Tupolev TU-134 crashes on approach into Phnom Penh airport, killing 64.