ST. PETERSBURG — Drinks in hand, the partiers took their place on bicycle seats that circled the contraption parked in a gravel lot outside Ferg's Sports Bar & Grill.

This was not quite a pub, not quite a bicycle, and not quite a bus.

This was PedalPub, an open-air pedal-powered party bus that recently debuted in St. Petersburg. Where the party rolls and how fast it gets there is entirely up to those on board, whose task is to move the bus using the pedals beneath their seats.

For Rose Wink, 32, of Tampa, the perks of the PedalPub are two-fold.

"To be honest, I think it's good because you can drink and have exercise at the same time," she said.

Wink, originally from St. Paul, Minn., near Minneapolis where the PedalPub first rolled, also felt a need to support a piece of her hometown while becoming acquainted with a new city.

"It's an opportunity to see more of St. Pete," Wink said.

In a center aisle between the two groups of five on either side of the bus, Krista Bertelson, PedalPub's local manager and one of three bus drivers, handed out waiver forms for the group to sign as she explained the rules.

Among them:

• Don't get off while the pub is moving.

• Don't become extremely intoxicated.

• Don't urinate in public.

"I'm curious to see where we go and how it all works," said Hayley Matrai, 25 of Tampa. "I like that fact that you can all go as a group to pubs and bars and meet new people."

Before embarking on their journey, the group tossed their cups and bottles into a trash bag — a requirement of all PedalPub patrons to avoid brushes with open container laws.

Bertelson reached up to tune an overhead radio to a classic rock station at the group's request before turning on a multicolored rotating strobe light that hung from the bus roof.

Then they set out. Pedaling with fury and strain, the group pushed the bus over bumps and bricks until its sailed across Central Avenue at its top speed of 5 mph. Pedestrians stopped and stared from sidewalks as it coasted by with 10 sets of cycling legs giving the open-air party bus the look of a centipede. Nearby, a man in a motorized wheelchair passed at a slightly faster speed.

Despite reservations some have expressed about the drinking shuttles being introduced in St. Petersburg, Bertelson says PedalPub's first few runs have gone seamlessly.

"We've had no problems yet," Bertelson said. "But we're not totally busy yet."

Bertelson, along with the owners of another pedal bus company, City Cycle Tours, struggled to gain permission from the city to operate the buses in St. Petersburg. They pointed out the concept's success in other cities, like Chicago, Austin, Denver, Savannah, and Milwaukee. Still, some officials remained skeptical and demanded the pedal buses conform with a host of restrictions.

"It's just so new to everybody that they don't understand them," Bertelson said.