Once a week or so, a limo driver named Ahmed Nizam shows up near baggage claim carousel No. 15 at Dulles International Airport, the spot where weary overseas travelers pour out. Dressed in a tie, white shirt and dark slacks, Nizam carries a sign showing someone’s last name.

It’s a ploy.

As passengers wheel their suitcases toward the taxi lines, Nizam makes his play. He asks them if they want a ride, an enticement that violates Dulles’s rules and Virginia law.

“It’s very risky,” he later said. “There are undercover cops.”

Unnoticed by most travelers, a little war plays out daily in the arrivals area at Dulles, home to more than 23 million passengers a year.

On one front, the “hustlers”: limo drivers who pretend to pick up passengers who supposedly had made reservations but are discreetly soliciting fares from fliers on the spot, without authorization.

On the other front, the undercovers: a squad of Metropolitan Washington Airports Authority police officers who pose as passengers wearing three-piece suits, toting luggage and speaking foreign languages.

Police say they want to protect passengers from getting ripped off or riding with limo drivers who aren’t properly insured. They also aim to block illegal competition that could hurt two groups: the large number of limo drivers with prearranged reservations to pick up passengers (which is legal); and the Washington Flyer taxi service, a collection of three independent cab companies that holds the airport’s contract to collect travelers.

At airports in some countries, solicitors are customary, legal and, at worst, in-your-face. But at most if not all commercial U.S. airports, the hustlers — as they are frequently labeled by authorities and fellow limo drivers — are prohibited by airport regulations and local or state laws. (In Canada, hustlers are known as “scoopers.”)

In the Washington region, hustlers thrive at Dulles, where international travelers — who might be unaware of stringent American airport taxi culture — are dumped out in one location as easy pickings. The hustling escalates during the summer tourist season.

A legitimate fare from Dulles to Washington should run $60 to $65, but limo drivers, whose sleek Lincoln Town Cars magnify the impression of upscale transport, charge as much as $100, if not more — and sometimes ask unsuspecting tourists to cover their parking lot fees.

Most hustlers are immigrants who say they’re just trying to piece together a decent existence. Many times, they have a reserved pickup and don’t need to solicit. But they still skirt the law, even if it means risking their livelihoods and facing the opprobrium of fellow immigrants who play by the book.

Drivers say that even in convention-heavy Washington, it’s difficult to make a living: Before the recession, they could accumulate enough daily fares for annual incomes that reached $60,000. Now, many drivers — who are often stuck with monthly finance payments for their Town Cars — say they make $30,000 to $40,000.

Cost-conscious travelers are axing black-car services from their budgets, opting for Washington Flyer cabs or for more economy with blue Super Shuttle vans.

It’s hard to know whether hustling at Dulles has become more or less frequent, because not every limo driver who solicits gets caught. Airport police catch about four hustlers a month, down from about eight in the mid-2000s, said David Hehr, an airports authority police officer. He said that increased enforcement might have scared limo drivers away from soliciting.

Once caught, drivers are slapped with a misdemeanor ticket carrying a fine of up to $500 for violating a provision of Virginia law requiring drivers to possess trip sheets showing the name and flight information of the passenger being picked up at Dulles. Sometimes, drivers appeal their cases in the Loudoun County court system.

On top of that, Dulles has its own rules. Hustlers busted three times earn a one-year airport ban. Banned hustlers can go to Dulles only if they have tickets to fly somewhere, but picking up friends or relatives at the airport is forbidden. If hustlers get caught breaking that ban, they risk trespassing charges.

Tara Hamilton, an airports authority spokeswoman, said solicitors are not much of a problem at Reagan National Airport. Sgt. Kirk Perez, a spokesman for the Maryland Transportation Authority police, said solicitors used to pop up at Baltimore-Washington International Marshall Airport, but he is not certain whether they still do.

‘A good day in May’

At Dulles, where intercom announcements regularly warn passengers about not accepting solicitors’ rides, the hustlers dress in the customary outfits of their peers: a shirt and tie, maybe a sport coat. They carry placards showing someone’s name — “Dr. James A.,” “N. Julia” — that could be a legitimate pickup. Or not.

Sometimes they work in pairs.

“If one driver wants to hustle, another guy down the hall informs him that a cop is coming,” said Faisal Memten, a driver waiting to pick up a prearranged passenger one recent afternoon.

Officer Hehr, 58, a former Arlington County fire captain, talks of his work with the elan of a lawman describing a drug sting or other bad-guy takedown.

“Oh, God, we had a good day in May. Two undercovers got solicited. We caught six total. I witnessed one of them from my cruiser outside — I had my binoculars going,” Hehr said. “I saw one of my undercovers coming out with a solicitor. I watched the car doors open. Then my undercover calls my cell and says, ‘It’s me. Come get him.’ ”

Then, there are the runners.

“The runners! Some see me in the terminal and they’ll run out the building into the parking lot,” Hehr said. “I will normally follow them out to the parking lot, and I will stop them by foot and ask, ‘What is your business?’ ” (The reply often uttered: Just stopped by Dulles to use the bathroom, officer.)

Mohammad Shahid, 48, of Fauquier County said he has been banned from Reagan National for hustling — but he still takes his chances at Dulles, where he solicited a Washington Post reporter.

“It’s not easy and depends on your luck. You have to stand there and look for professional people,” said Shahid, who emigrated 17 years ago from Pakistan. “Getting a ticket is all right. I’m not feeling pain for the ticket, but if you’re banned, it’s painful.”

Drivers sometimes contest their bans in emotional appeals hearings at the airport. “Operators will come in with pictures of their kids and family,” said Chris Browne, the airport manager, who adjudicates the hearings.

As for Nizam, 41, whose previous jobs have included running a liquor store, a fried chicken joint and a convenience store, he said that being a limo driver has become too expensive and time-consuming. Gas costs $40 a day, insurance is $300 a month, and the new air conditioning unit set him back $1,200. A note stuck to the dashboard of his Lincoln Town Car reads: “Oil change.”

“I want to quit,” Nizam said. He wants to spend more time with his wife and children.

“My family doesn’t like me driving,” he said. “I’m looking for a job.”

But until he finds one, he’ll have to keep up the hustle.