http://www.google.co.jp/logos/shinkansen.gif

The Shinkansen is a network of high-speed railway lines in Japan operated by four Japan Railways Group companies.
http://en.wikipedia.org/wiki/Shinkansen

Cool Doodle! – JR West will run special Hikari services on December 6, 13 and 14 to officially retire the 0 Series train.

http://en.wikipedia.org/wiki/0_Series_Shinkansen

if, like Pascal and me, you were searching for the "OOG" in the search engine's doodle, it's there:
http://www.zorgloob.com/images2/shinkansen-oog.jpg