Starting March 1, juveniles who commit misdemeanors on buses and Max trains will be booked and detained for up to 36 hours at the Multnomah County juvenile court facility, authorities said Thursday.

"It shows we're serious when we say 'we're not going to take it anymore," said Shelly Lomax, TriMet Director of Safety and Security.

TriMet says that young people intimidating riders and getting in fights on trains or near stations is a main source of complaints and adds to the impression that the system is out of control.

There have been several assaults in recent months on or near the Max line.

Right now youths who cause problems on TriMet vehicles don't face a serious consequence, according to Multnomah County Senior Deputy District Attorney Tom Cleary.

"We talking about people who engage in behavior that's dangerous to themselves and other people," said Cleary. "We're not interested in people who didn't pay their fare.

Cleary said the policy shift has been two months in the making, with the full cooperation of TriMet and the police agencies who respond to calls. Youths facing a misdemeanor charge will be taken to the intake center at Juvenile Detention in Northeast Portland. Parents will be called, and officers will work out an action plan with the offender.

There are five intake slots at the facility, and one transit officer said he thinks there will be a need for more slots once the changes take effect. But Sargent Eric Boothby applauds the move. "It's a great tool," he said.

TriMet is adding more officers to patrol the system. Five will be added on the west side and officials are still in discussions regarding how many will be added to the east side.