It costs $2.80 for a child and $5.50 for an adult to catch the bus in Rangiora.
But there was no charge for Nismo the five-month-old puppy, who snuck onto a Metro Blue Line bus on Southbrook Rd headed for Christchurch.
The pooch led bus users on a chase around the bus as he craftily evaded capture.
Fortunately after a brief ride on the bus, which goes from Rangiora into the city, Nismo was guided off.
He then took off around Southbrook School grounds, before finally being collared and taken back home by animal control.
Nismo's owner Jess said she had turned around to make her son's lunch and was just putting the spread back in the cupboard when she noticed her dog was missing.
"We've recently moved house and it's not properly fenced. We're getting a fence put up on the weekend so this won't happen again," Jess said.
A district council spokesman said: "We like to promote public transport because we have so many commuters, it is nice to see pets are getting the message too."
Nismo has carved a wee bit of fandom on the Waimakariri District Council's Facebook page.
Jess said she did get a 'bit of a telling off' by animal control but reassured them she was getting the fence put in at the weekend.
Jess said it was nice that he had "made lots of peoples' days."
But now Nismo is enjoying the sun from a secure position, tied on a long lead in the backyard.
"He'll have more adventure," she said. "Just next time it might be a good idea if he does it with his owner."