The 1970s were when the term of bōsōzoku first truly began to emerge. This was a period of time characterized by actual riots between police and many of these youth groups. The term, bōsōzoku, was not actually created by these biker groups, but was eventually widely adopted and used by these various groups. In the 1980s and 1990s, bōsōzoku would often embark on massed rides, in which up to 100 bikers would cruise together slowly en masse down an expressway or major highway. The motorcyclists would run toll booths without stopping and would ignore police attempts to detain them. New Year's Eve was a popular occasion for the massed rides. The bikers would sometimes smash the cars and threaten or beat up any motorists or bystanders who got in the way or expressed disapproval of the bikers' behavior. Participation in the gangs peaked at 42,510 members in 1982. This made bōsōzoku the prevailing form of youth delinquency within Japan.