Adeniyi Isiaka staggered out of O’Hare airport into a chilly, rainy afternoon. He had just landed at O’Hare after a 25-hour series of flights that originated in Nigeria, where he’d been visiting his family. He was exhausted, and he just wanted a cab to take him to his home in Chicago Heights. Idling by the curb was a car marked Midwest Taxi.

“I only have $100,” Isiaka replied. “Just drop me at the Blue Line.” It was only Isiaka’s second trip out of O’Hare, and he didn’t know there was a Blue Line stop right inside the airport.

Chicago cabs are closely regulated by the city’s Department of Consumer Services, which issues the numbered medallions taxis are required to display on their hoods. (The department auctions off a limited number of medallions every year, but once they’re issued, drivers and cab companies are free to sell them on the open market, where they can fetch around $50,000.) A taxi operator who violates the service standards set by the department–by charging more than the legal rate, for example–risks losing his medallion.

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The suburban taxi trade is much less closely regulated than that of the city. “The state licenses taxis, but it doesn’t regulate them,” says David Druker, spokesman for the Secretary of State. “To qualify for a taxi license plate, you have to prove that you’re carrying $250,000 per car of insurance for bodily injury, plus another $50,000 of insurance against property damage, and you have to pay the $78 fee. Beyond that, the state leaves the regulation of taxis to the municipalities.”

According to Jay Kleeman, service quality director for American Taxi, a Mount Prospect taxi dispatch service, most suburban taxis abide by the rules. “The ones most inclined to cheat are individual operators who are not associated with a dispatch service, because they have nothing to lose,” he says. “I want to choose my words carefully here, because there are a lot of great one- and two-car operations that hold very high standards. But anyone can buy a car, get it painted and lettered like a cab, and then install a meter and fix the software to charge whatever they feel like charging. And maybe the municipality of origin has laws governing the allowable rate, but once the taxi leaves that area it’s very difficult for the police to respond knowledgeably to a customer complaint.

“How much did he charge you?”

“You know you’re not allowed to pick up at O’Hare,” I said.