Frank Greco, left, talks with his customers, construction workers at a site in the Shaw neighborhood of Northwest Washington. Several catering trucks jockey for position at construction sites around the city. (Amanda Abrams/FOR THE WASHINGTON POST)

Frank Greco and his employee Diane Gomez know they’re running late. The last stop took 10 minutes longer than usual, and in their business, that short amount of time can be everything. On this October morning, it means the duo has seven minutes to get from Southwest Washington to the next construction site in Northwest’s Shaw neighborhood.

“You got it, Frankie. Go!” yells Gomez, peering into the passenger side mirror. Greco nimbly edges his truck past a stalled car to breeze through a yellow light.

But they’re not fast enough. Pulling into an alley next to the former Wonder Bread factory just off of Seventh Street NW, Greco groans. “She’s here.”

Ahead on the sidewalk is a catering truck similar to the one Greco is driving: the same silver side panels that raise to reveal a grill, heated shelves and a refrigerated section, the same three-person cab. Except that this one’s already mobbed with customers.

Wasting no time, Greco and Gomez jump out and begin setting up. Gomez, the grillmaster and Greco’s sole employee, hoists the panel covering a crowded griddle with steaks, cheeseburgers, pork chops and chicharrones; the food is just about ready to go. Meanwhile, Greco opens the other panels, checks appearances and sets up a rickety cash table as fluorescent-vested construction workers surround the truck.

Like the gourmet and specialty food trucks that have been garnering attention over the past couple years, these vehicles are restaurants on wheels serving a devoted clientele. But in this case, the trucks are virtually invisible to the layperson: They serve construction workers, spending weekdays from morning to early afternoon driving from site to site throughout the region, serving breakfast and lunch. Development in the District has picked way up since the 2008 downturn, and their business is booming. But as a result, competition is getting intense.

“Three or four years ago, it was dead,” says Greco, 57. The Millersville, Md., resident is a 20-year veteran of the business who serves 10 sites around the District. “It’s changed dramatically. Now there’s more jobs than I can handle. But there’s a lot more people selling food.”

Ask the superintendents of the various construction jobs around the District — who pick the trucks that feed their workers — and most will tell you Greco’s food is a cut above the rest.

“It’s the best truck I’ve ever seen,” says Bryan Langan, a site supervisor for Clark Builders Group. “The guys really like his food. It’s all fresh.”

That freshness is a point of pride for Greco, who has worked in food service his entire adult life. He says even construction workers have become more picky about the quality of their meals.

“I used to use more canned stuff, but you can’t do that any more,” he says. “People want homemade food now.”

Greco, who estimates he goes through $400 to $500 worth of ingredients per day, says he regularly puts in 15-hour days shopping for supplies, then prepping and cooking on the truck’s grill before heading out for the day. He serves what could be described as guy food: hearty, rib-sticking dishes plus a few lighter options. And there’s lots of variety.

Offerings on a given day might include up to 10 various grilled meats, plus entrees such as lasagna, meatballs, fried rice, tamales and shrimp scampi pasta, as well as side dishes such as green beans, hash browns, plantains, sauteed zucchini and fried eggs. One side of the truck holds cold offerings and has just enough space for a small salad bar, plus cut fruit, though the fresh offerings tend to go a lot more slowly than the rest.

And it’s all dirt cheap: A plastic foam container loaded with pupusas, lasagna and chicken wings might go for around $5.

But no matter how cheap or tasty Greco’s food might be, the market is just begging for entrants.

A study by the Associated General Contractors of America released in September reported that construction employment in the District is the highest it has been in a couple of decades. For businesses like Greco’s, the sites provide a clientele who might otherwise have to bring food from home or eat at a convenience store. It’s not surprising that increasing numbers of vendors are joining in.

There might be a couple dozen of the trucks serving sites around the city, but the District’s Department of Consumer and Regulatory Affairs does not have any data on whether this particular segment of the food-truck industry has increased over time. The agency regulates the vehicles like it does other mobile food vendors and does its best to crack down on “gypsies,” the unregulated vendors working the field. Construction catering trucks are nowhere near as closely monitored as the more consumer-oriented food trucks, Greco says. Even when the trucks park on the street instead of on construction properties, Greco says, they do so for a much shorter period of time.

“The fact that they move from site to site to site does complicate enforcement a bit more,” says DCRA legislative and public affairs officer Helder Gil.

That might have been in play at Greco’s and Gomez’s next stop: the future Walmart rising from a parking lot near First and I streets NW. Around 10:45 a.m., just before Greco arrives, a woman in an SUV swoops in, peddling to-go containers of grilled tilapia, salmon or chicken for $8 to $10 out of the back of her car. Then she quickly leaves.

But this construction zone, located far from retail establishments, has enough business for everyone. Greco’s real nemesis is the woman who showed up at the old Wonder Bread factory. She’s now getting to three of his 10 sites on a daily basis, arriving about 15 minutes before him at each one and taking away a good percentage of his customers.

On this day, she’s already at the next stop as well, an in-progress residential building in NoMa. “She runs a good truck. I’ve got to give her credit,” says Greco grudgingly.

The fiery woman who identifies herself only as Anacleta, has added a few mouthwatering items to a menu that otherwise looks similar to Greco’s, such as a pulled chicken sandwich with cucumbers and cilantro, and a robust coleslaw that includes radishes and feta cheese.

About five minutes after Greco arrives, so do the D.C. police, who pull over and ask to see Anacleta’s permits. Apparently, the construction superintendent had complained that she’s not approved to sell at the site. But technically she’s on public property (the street) and produces all the right documents, so the police have few options.

Greco is convinced that Anacleta’s truck is longer than the maximum 181 / 2 feet permitted. Size matters: Greco formerly owned three trucks that were too long and finally sold them after receiving repeated tickets. But his complaints to the DCRA have so far gone unheeded. A couple of stops later, at the two-block-square O Street Market site, there she is again.

“This business used to be easier,” Greco says with a sigh.

Although he complains about the competition, Greco’s love for the job is evident in his easy, joking manner with customers. There’s a sense of freedom to it that he never found standing in the back of a kitchen.

“I like doing this,” he says. “As long as I’m making some money, I’m okay.”

Amanda Abrams is a freelance writer in Washington.