— Police at Raleigh-Durham International Airport have handed out more than 100 citations to drivers with the Uber and Lyft ride-sharing services in recent weeks, saying the private vehicles used in the services don't comply with the airport's permit regulations.

In order to standardize the service and fares charged by taxis that serve the airport, RDU requires all cabs to obtain a permit, carry proof of $1.5 million in liability insurance and have drivers who have undergone background checks and physicals.

Ride-sharing companies, which use smartphone apps to arrange rides and usually charge less than taxis, said they don't need to meet such standards, and they called RDU's crackdown as an attempt to limit competition.

"Unfairly ticketing drivers is simply an effort to limit consumer choice and opportunity and does nothing but hurt the people who rely on Uber to make a living and travel safely around town," Uber spokesman Taylor Bennett said in an email to WRAL News.

Drivers for the ride-sharing services said they have been picking up and dropping off passengers as far away from RDU police as possible to avoid detection.

RDU taxis quote an estimate of $30.80 to drive someone to Raleigh, which they say is a 14-mile trip. A 14-mile trip through Uber would cost about $19.35, while Lyft would charge $17.53 for the trip. As for tips, Uber says a 20 percent gratuity is figured into the price of a ride, while Lyft allows people to add tips through their app

Traveler Kendra Mangan also called the $50 citations and prospect of misdemeanor trespassing charges for repeat offenders unfair, saying she likes the convenience and lower cost of ride-sharing.

"It should be a free market," Mangan said. "Transportation is up to the person that is getting into the car, and it's sort of helping the taxis monopolize."

Taxi driver Lee Churchill said, however, that she finds it unfair that Uber and Lyft drivers don't have to pay for a commercial license or meet other requirements that she has to meet.

"They're really hurting our livelihood, but also the safety, health and welfare of the general public," Churchill said.

RDU spokeswoman Mindy Hamlin said the ride-share services simply don't meet the standards the airport has set, but she said airport officials are trying to reach a compromise with Uber and Lyft.

"We want to get ahead of this," Hamlin said. "We know that it's a service that some of our customers want, but at the end of the day, we do have to ensure the safety of our passengers."

Uber and Lyft maintain they provide blanket insurance to cover their drivers, but Hamlin said the companies haven't produced any proof of that.

"We are committed to standing strong with drivers and passengers every step of the way, fighting any citations, covering relevant costs and making policy progress," Lyft spokeswoman Chelsea Wilson said in an email.

"We will continue to safely and reliably move people around the city, including to and from the airport, while we continue to work with officials on a proper process that embraces ride-sharing and greater options," Uber's Bennett said.