But one company is under fire, accused to illegally serving alcohol on its rides.

From party barges to bathtubs, even firetrucks – there is no shortage of options to explore Nashville on wheels.

It’s a type of transportainment that’s seeing constant evolution.

“There’s no lack of innovation in beer industry,” said Benton McDonough, Executive Director, Metro Nashville Beer Permit Board.

But with that innovation, comes safety concerns that are now taking a front seat.

According to a recent complaint filed anonymously with the Metro Nashville Beer Permit Board and Tennessee Alcoholic Beverage Commission, party wagon company Nashville Tractor has been allegedly selling alcohol illegally on board its rides for at least a year.

Video obtained by News 2 shows a cash bar in action and employees appearing to list the beers for sale Thursday afternoon.

McDonough is investigating.

“It’s a very serious matter,” said McDonough. “Anytime you have someone selling alcohol without being properly permitted, they haven’t gone through the proper steps to get permitted, that’s a serious matter.”

Riders are permitted to drink on board, but according to state law, selling beer or alcohol on the rides is prohibited.

“What we see is that typically they are BYOB, they’re bring your own beer on board,” said McDonough. “And so they do not have the authority to sell on the party wagon.”

But on the company’s website, the exact opposite.

It reads, “Sorry no outside drinks allowed on the Nashville Tractor. Our wagon is stocked with ice cold beers and other drinks so no need to BYOB and carry drinks around town.”

We called Nashville Tractor’s owner.

He told News 2, “I’m sorry, we’ve got no comment.”

In the complaint, the company allegedly uses a catering permit to sell the beer and alcohol through a partnering bar.

According to the Beer Board, they have no record of such permit.

Even so, McDonough said such a permit can only be used at a precise location, not on a ride, indicating a violation.

McDonough said he spoke to the bar management.

“They admitted to the fact that there was a misunderstanding and how the law was being applied by them versus how we interpret the law,” he said.

As the investigation continues, McDonough said corrective action has been taken.

A start — the plan to issue more off-sale permits.

This allows operators to partner with bars for customers to purchase alcohol and then drink it on their rides.

“Our biggest concern is to make sure that the public is safe,” said McDonough. “But, we also don’t want to stifle innovation at the same time.”

McDonough said the partnering bar of the Nashville Tractor has applied for an off-sale permit.

The TABC and Metro Police are also investigating.

A civil penalty could range in up to a $1,000 fine — if criminal, up to $2,500.