Jodi Timmersman has been a substitute teacher looking for a full-time job. So with prospects not looking great for landing one this fall, she hit the bricks.

"If someone told me I'd be pushing around a hot dog cart," she says, laughter cutting short her sentence.

Timmersman, who lives in Cloquet, has been working Superior Street in downtown Duluth this summer with her cart, called D's Dogs. It's perhaps a sign that the national food cart and food truck trend is trickling into the region.

"We heard about Minneapolis and the food cart craze," she said of the inspiration to ease the financial stress of joblessness.

More than 50 food trucks and vendors can be found listed online roving Minnesota's largest city since it began experimenting with them in 2010. Across the country, the trend has also exploded, forcing city officials to create special rules to keep traffic flowing on sidewalks and streets and to assuage traditional restaurant owners who could suffer a loss in customers.

For now, Timmersman's enterprise is more of a novelty in Duluth. There are also at least three food trucks roaming downtown, the hill toward Miller Hill Mall, and West Duluth.

There are no specific rules for the food vendors in Duluth, just an OK from the Minnesota Department of Health and the acquisition of a city peddlers permit.

"We have been getting a lot of phone calls," said James Backstrom, manager of the Department of Health's Duluth district office.

Backstrom said the inquiries have involved people who are kicking the tires on the idea of converting a truck for food. There are also those who are using a national company that custom builds or remodels trucks for customers, another sign that the trend has ballooned beyond niche, Backstrom said.

The Department of Health issues a license, and then it is up to the vendor to make sure local rules are being followed. The state license requires that vendors not spend more than 21 days at one location and includes an initial inspection of the operation and regular checks after that.

Backstrom said his department is heartened by the trend because the trucks often offer items beyond the expected greasy fair foods.

"It used to be just corn dogs and other fried food," he said. "Now they're getting better with food options. That's good from a healthy food perspective."

For Timmersman, it's mostly hot dogs. She has soda and chips available but keeps things simple.

"It's a compact cart," she said. That's a plus, because she's honoring the city permit admonition that she keep moving and not stay in one spot for too long.

She plies Superior Street from 11 a.m. to about 1:30 p.m. Monday through Friday.

At various hours, including evening in nightlife areas, the food trucks The Rambler (specialty sandwiches) and Habaneros (Mexican) and Chow Haul (variety) can be found. Duluth pizza restaurant Green Mill also has a mobile unit, and shaved ice and ice cream trucks have been more visible during a hot summer in Duluth.

"They've got their food, and we've got ours," Timmersman said, shrugging off any perceived competition.

All of the vendors have Web sites and social media contacts so eaters can keep up with their locations.

Timmersman said the reaction downtown has been invigorating, with some businesses like US Bank asking her to set up outside the office during lunch time.

"It's been a blast," she said of getting to know people downtown. She has yet to hear complaints from regular restaurants losing part of their lunch crowd.

She said staffers at Pizza Luce were jazzed by her presence.

"They wanted to know what was up," she said. Then they offered to trade some pizza for hot dogs.

It's inevitable that competition concerns will come, and one downtown business group is keeping an eye out.

"This is definitely on our radar," said Darlene Marshall the special events coordinator for Duluth's Greater Downtown Council. She invited Timmersman to sell her food at Movies in the Park at Leif Erickson Park this summer.

"It's something the council is looking into," Marshall said of how the new food vendors will be supervised.

Marshall said she expects the city will need to follow others in creating special rules to control the influx of vendors.

"We're going to walk a fine line," Marshall said. She said she expects some kind of compromise between vendors and restaurants.

She said Duluth can learn from mistakes and lessons learned in other cities.

Dan Hartman, president of the Duluth City Council, has talked about setting up more specific rules for vendors as an encouragement to have more come in.

"The city has a lot of rules infringing them from coming in," Hartman said.

He'd like to follow what Minneapolis has done in easing the strict rules that require vendors to keep moving. He said the food trucks are also finding it difficult to find places to park.

He is also wary of hurting local restaurants.

"The last thing I want to see is a hot dog stand in front of the Coney Island," Hartman said, referring to the long-established hot dog restaurant on East Superior Street.

He said there are pockets downtown where it would be an enhancement to lure vendors in. But bringing them into a restaurant district like Canal Park wouldn't make sense, he said.

The City Council had a unanimous vote recently to prod the city administration into tweaking food vendor rules.

"As soon as we have a policy we'll be going to them," Marshall said of helping the city council strike a balance.

Timmersman intends to keep her business going past the summer, working on weekend nights and serving an always hungry college crowd.

She knows that audience, she said, since she and her husband, Dustin, are both University of Minnesota Duluth graduates.

She isn't so sure about continuing through the winter.

"A man from Winnipeg said people stop buying hot dogs when they're wearing mittens," she said.