GO Trains use a "proof-of-payment" policy where the fare system is run on an "honour system" and passengers are expected to carry a paper ticket or Presto card to prove that they paid for their fares. To increase compliance, passengers may be subject to random fare inspections at any time during travel. This system is designed to reduce costs and improve efficiency. Enforcement of this system is carried out via Metrolinx's By-law No. 2 that, by reference to the Provincial Offences Act, imposes a $100 fine for fare evasion.