The fashion truck trend made its Pittsburgh debut last summer, and based on the public's positive response it won't be leaving town anytime soon.

As temperatures pick up, so will the trucks' schedules as they pop up at parking lots and businesses across the region in the coming months.

These boutiques on wheels are like food trucks, but instead of filling stomachs they fill closets with apparel and accessories. In Pittsburgh so far there are four of them: Roadie (owned by Cailey Breneman), Style Truck (owned by Jackee Ging), Broke Little Rich Girl (owned by Samantha Lugo) and the Vintage Valet (owned by Marissa Zimmerman).

At first, passers-by were hesitant to peek inside and seemed a bit confused.

"They thought it was a food truck," Ms. Lugo says. "They didn't know they were supposed to go inside."

After a few weeks on the road, the trucks started to catch on and attract a varied clientele.

"One of my first customers was an 80-year-old woman and the next was a teenager buying some funky jewelry," Ms. Ging says.

Like the food trucks, the mobile boutiques strive to cater to a variety of tastes so they can complement each other's offerings rather than compete. They also see benefits in working together, even meeting on occasion to swap stories or participating in fashion truck roundups across the region. One of the first roundups of the season will be the Ladies Night Out event Friday evening at SouthSide Works (details at www.southsideworks.com), where three of the four fashion trucks will be parked. Roadie, a rustic 1981 RV, recently died, Ms. Breneman says. She's considering a replacement so she can hit the road again.

Separately, many are planning to be out and about most weekends this spring and summer, with the Strip District among their more popular spots. Parking on city property can be tricky due to regulations regarding where trucks can park and for how long. They've had better luck partnering with private businesses for an afternoon or an event. For instance, last year Roadie teamed with Bar Marco in the Strip District and Union Pig & Chicken in East Liberty for a few outings, and Style Truck connected with Urban Cottage boutique, which closed last month in Bloomfield.

As the weather got colder, the fun -- and the trucks' following -- tapered off, with many calling it quits for the season in November. Style Truck continued to build its brand by having a booth at the Peoples Gas Holiday Market in Market Square. Broke Little Rich Girl kept its travels going through the winter by equipping the truck with sliding doors that held the heat inside so people could shop and stay warm.

Truck owners have looked to other cities for tips. Nationwide, fashion trucks come in a mix of looks and sizes, from 1960s-style trailers and 18-wheelers to vehicles that resemble an ice cream truck. The trend has spread from a couple dozen dotting the country in 2011 to about 400 today, according to the Los Angeles-based American Mobile Retail Association, a group that supports the efforts of these nomadic retailers. California, Texas, New York and Washington, D.C., are spots where the presence of fashion trucks seems to be picking up, says association cofounder and president Stacey Steffe.

Ms. Lugo of Broke Little Rich Girl serves as the association's Pittsburgh ambassador. Some of the other local trucks are part of the association, too. It offers sessions that educate truck owners about the ethics of mobile businesses (not parking a mobile boutique next to a brick and mortar boutique, for example), and how to coordinate events and collaborate with other businesses.

Each truck owner also pulls from her professional background to grow the business. Ms. Breneman is a stylist who travels the country assisting with photo and video shoots. Some of what Roadie stocks are items she has picked up while on the road or used for a shoot. Ms. Zimmerman started making plans for the Vintage Valet about a year ago while a student at The Art Institute of Pittsburgh. Ms. Ging had some retail experience after college but, like Ms. Lugo, has spent her career in marketing and business.

And the trucks themselves? Their backgrounds are just as diverse -- and not nearly as glamorous prior to being converted into boutiques on the go. Style Truck was "green and rusty," Ms. Ging says, and had been used for military purposes and for storing tools. Broke Little Rich Girl hauled tools and wood for a construction business and was bright metallic blue before getting its pink-and-white makeover. Ms. Zimmerman liked the smaller build of a U-Haul truck for her Vintage Valet. While Ms. Breneman considers Roadie's future, she'll likely use a smaller vehicle such as a Jeep, like she did prior to buying the RV, to move inventory around.

The trucks try to keep their selections fresh and on trend by going on buying trips in New York and other cities. Earlier this month, Ms. Lugo went to Italy to seek out new styles.

All try to keep prices affordable and less than $100 with a handful of pieces with higher price points.

With some experience -- and miles -- behind them, the roaming boutique owners are looking forward to booking new appearances and bringing style to more sections of the Steel City.

"People are starting to hear the buzz," Ms. Ging says.

Just in time for Pittsburgh Fashion Week, there's a new mobile boutique on the block.

Earlier this month, Marissa Zimmerman, 31, of Monongahela took her shop on wheels, the Vintage Valet, out for its inaugural spin at the Perryopolis Flea Market. Fashionistas will be able to find it out and about during Fashion Week, including Tuesday at the pop-up fashion display in Market Square from 11 a.m. to 2 p.m.

"I've always loved fashion," Ms. Zimmerman said. Plus, she likes to travel, so she decided to combine the two. She came up with the idea about a year ago while a student at The Art Institute of Pittsburgh studying fashion and retail management.

"I just started looking on the Internet and realized, my gosh there are lots of these elsewhere, such as California, New York and Texas," she said.

Since early summer, three others have cropped up in Pittsburgh: Roadie, Style Truck and Broke Little Rich Girl. Ms. Zimmerman's truck offers contemporary women's clothing with a vintage twist, so expect to find lots of crocheted looks, lace, pleats and floral prints. About half of the apparel is made in America. Pieces range from about $20 to $55.

"So far, people really like it," Ms. Zimmerman said. "They look inside and say, 'Am I supposed to go in?' It's exciting to see people's reactions."

To learn more, visit thevintagevalet.com.