If we knew what city/route/service and day, we might be able to get a better idea.

• Sometimes operators declare a ‘fare holiday’ when everyone rides free, usually as compensation for some major fuckup previously, or for some other PR stunt. Metlink in Wellington doesn’t charge on Christmas Eve, Christmas Day, or New Year’s Eve.

• Operators sometimes half-strike and refuse to collect fares.

• The specific route, service, or time of day might be free.

• It’s an express service that you can’t pay cash on (only fare cards) and it’s easier/nicer to tell you to ride for free than to tell you to get the next bus because they don’t take cash.

• You might be part of some group (youth, students, elderly) that doesn’t have to pay.

• Something is broken and they can’t collect fares.

• They don’t want to deal with the big banknote you had.