Essdras M Suarez/Globe Staff

Derek Bass was cited for fare evasion by undercover MBTA agents at the Park Street T Station recently.

Essdras M Suarez/Globe Staff

Though the loss from fare evasion is hard to calculate, planners estimate it may be in the tens of millions of dollars annually.

Wendy Maeda/Globe Staff

Transit Police have devoted increasing attention to the problem, with officers writing a record 3,482 tickets last year.

Wendy Maeda/Globe Staff

Paul Cravedi (pictured) said he was outraged by fare evaders using electronic gates in rapid transit stations.

Essdras M Suarez/Globe Staff

The new law makes the fine $50 for a first offense and requires payment or a request for an appeal hearing within 30 days.