blue traffic ticket; minor violation ticket
Refers to a blue-colored ticket issued for minor traffic violations in Japan, as opposed to a red ticket (赤切符) for more serious offenses. Often used in contrast with 赤切符.
See also: 赤切符
I got a blue ticket for speeding.
second-class ticket
Obsolete colloquial term for a second-class ticket, especially on trains. No longer in common use.
In the old days, you could ride in a second-class car with a blue ticket.
Compound of 青 (blue) and 切符 (ticket). The traffic ticket sense comes from the blue color of the paper form used for minor violations. The obsolete second-class ticket sense also derives from the blue color of such tickets historically.