"Our goal is to keep the system safe, and keep the people safe on the system," Sgt. Trent Stephens says.
Some of the things they're looking for include littering, smoking outside of designated areas, spitting, and threatening behaviors.
They say it's all part of an effort to make sure everyone's ride is a safe one.
"Generally we're not heavy-handed," Sgt. Tony Oliver says. "We emphasize a zero tolerance approach; however, zero tolerance in this case means we're not going to let anything go by without talking to them about it."
Officers are primarily enforcing the rules along bus routes that service high schools.
"It's designed to educate students that are returning to our bus system, and new students on to our bus system of what our expectations are regarding good behavior and proper respect for everybody on the transit system," Sgt. Oliver says.
During last year's enforcement, police banned 68 people for disorderly behavior or criminal activity, and it's a number they say is decreasing.
"This is a highly successful program," Sgt. Olivier says. "We've been doing this for four years now, and every year the stats get lower and lower, which is a good indication that it's working."
Anyone who violates the Pierce Transit conduct codes can be banned for 90 days.