The cars started lining up an hour before pop music star Gwen Stefani wrapped up her concert at St. Paul’s Xcel Energy Center.

As 5,000 concertgoers streamed out of the arena, the drivers went to work. “Do you want an Uber ride?” asked one. Another held up a big piece of paper marked “Uber” and told passersby they could save a lot of money by paying him cash for a ride.

In the scramble to get home, it was impossible for customers to tell which of the drivers actually worked for Uber. Half the vehicles were not displaying corporate logos, as required by law. Most of the drivers openly solicited potential customers on the street or agreed to take cash for a ride, tactics that are illegal for Uber drivers.

Such scenes have become common in the Twin Cities, where Uber and the rival service Lyft now provide more rides than traditional taxicabs. Operating with little city oversight and less stringent rules than taxis, an informal and dangerous ride-sharing culture has emerged in which people casually hail unmarked cars and barter for rides.

Uber and Lyft both tell customers they shouldn’t get in vehicles unless they first book their ride through the companies’ phone apps. But many people ignore the warnings, accepting rides from strangers who sometimes turn out to be predators.

At least five women in the Twin Cities have been abducted or assaulted by men who presented themselves as Uber drivers in the past two years, police reports show. In Atlanta, Los Angeles and other cities, men pretending to work for Uber have been charged with attacking women after luring them into their cars. Chicago police warned last year of robbers posing as Uber drivers.

“The whole idea behind this service was that people were supposed to know what they were getting,” said St. Paul Council Member Dan Bostrom, a former policeman. “I am concerned that folks are putting their lives in the hands of somebody they don’t know in a vehicle they don’t know anything about.”

In recent months, Star Tribune reporters repeatedly observed drivers ignoring regulations aimed at protecting the public, making it difficult to distinguish a legitimate ride-sharing vehicle from a fake.

Drivers can be cited for infractions, but regulators in Minneapolis and St. Paul have done little to crack down. The vast majority of Uber and Lyft drivers caught breaking the rules have gotten a warning, records show. Altogether, drivers here have been fined $5,500, vs. millions of dollars in penalties in other cities.

Moreover, regulators are largely absent when Uber and Lyft drivers are busiest, such as after concerts or sporting events and outside bars at closing time.

After being told of the Star Tribune’s findings, officials in Minneapolis and St. Paul pledged to improve enforcement.

“We don’t want to outlaw the convenience — we want to target the rule breakers,” said Minneapolis City Council Member Jacob Frey, chief author of the city’s ride-sharing ordinance. “And we can do that through additional enforcement, which clearly needs to happen.”

App use encouraged

Uber and Lyft officials say riders who go outside the app are taking their chances because they are getting into a vehicle without knowing whether the driver has passed a criminal-background check or is driving a safe vehicle. Moreover, even if the driver is with Uber or Lyft, passengers will not be able to collect from the companies’ insurers if they’re involved in an accident during an unofficial trip.

“For the safety of drivers and passengers, solicitations made outside of the Lyft app are strictly prohibited,” Lyft said in a written statement.

In response to the Star Tribune’s reporting, Uber said it recently began a public awareness effort. The Twin Cities campaign, which will include e-mails to drivers and pop-up messages to riders during surge periods, advises customers to “request your ride before you go outside.”

Some veteran drivers say the problems are a direct result of the ride-sharing companies’ pricing model, in which rates spike when demand is high.

Though Uber and Lyft rates are typically lower than a traditional taxi, a cheap ride is often hard to find after midnight. One driver said he charged a passenger $121 for a 7-mile trip last Halloween — a trip that normally would have cost about $15. Unlike taxicabs, which can be hard to find at bar closing time, Uber and Lyft can charge whatever they want. The companies also are known as being friendly to customers who have had too much to drink.

Drivers said they are sometimes mobbed by people seeking a cheaper ride home, who knock on their windows pleading for a cash ride. Drivers often accept, even though local rules forbid taking street hails. City officials have expressed concern about the level of chaos and are taking steps to ensure the orderly flow of traffic at bar time in downtown Minneapolis.

“It’s crazy when the bars close,” said Todd Boeser, who has driven for both companies. “If you’re in Uptown [Minneapolis], people jump out and stop you.”

Boeser said he has accepted an illegal fare just once, when a group of drunken out-of-towners piled into his car and offered him $20 for a 2-mile ride. He thinks many of the people providing illegal rides are not affiliated with Uber or Lyft.

“It’s not safe for the passengers, because they’re unaccounted for,” Boeser said.

In February, a 35-year-old woman was flagged down by the driver of a black sedan after she walked out of a Franklin Avenue restaurant. The driver said he worked for Uber, police records show.

Heather, who asked to be identified only by her first name, said her first hint that something was wrong came when he promised not to charge her for the ride. Then, a few blocks from home, he asked if she lived alone.

Heather decided to cut the trip short. The driver chased her down.

“He pushed me into the door and tried sticking his tongue down my throat. He grabbed my breast at one point,” Heather said. “It was really scary.”

In August, a man posing as an Uber driver tried to sexually assault a passenger after picking her up in the Uptown area of Minneapolis and driving her to Woodbury, records show. Police said the woman fought off her assailant, who fled the scene.

St. Paul City Council Member Amy Brendmoen said she’s concerned that people are putting themselves at risk. “We have been told that since we were 5 years old — don’t get into a car with a stranger,” Brendmoen said, adding that it may be time to add more consumer protections.

An Uber spokeswoman noted that customers who use cars without going through the app lose out on safeguards built into the system, such as the ability to identify drivers and report problems.

Unlike taxicabs, which are easily identifiable on the street, Uber and Lyft vehicles tend to blend anonymously into traffic.

Many drivers said they prefer not to put stickers featuring company logos on their windshields, even though the stickers are required.

“I didn’t want to be a target for cabdrivers, so I decided I wasn’t going to put those in my window,” said Lyft driver Barbara Peppe, who continued driving without the logos after St. Paul regulators warned her about the violation in January.

In Minneapolis, one of the most heavily trafficked intersections for ride sharing is the Uptown neighborhood of Hennepin and Lake. Outside the nightclub Cowboy Slim’s, Uber and Lyft drivers park at the cab stand and solicit customers. Star Tribune reporters observed a police officer occasionally shooing them away one night earlier this year, only to see them return minutes later.

Lyft driver Liban Hassan, driving a Honda minivan, pulled up alongside a reporter and made his pitch: “$30? Got money? Want a ride?”

A few days later, Hassan denied doing anything wrong. “I know the only people who can pick up for cash are the taxi people,” he said.

Grant Wilson, the top ride-sharing regulator in Minneapolis, said his team has conducted just a few sting operations since licensing Uber and Lyft in 2014. He doesn’t have the authority to tell Uber or Lyft to remove drivers caught operating illegally.

An Uber manager said he was unaware of any Minnesota drivers who have been removed for illegal pickups or other violations. Lyft officials declined to answer questions.

Enforcement attempts

Earlier this year, regulators in Minneapolis summoned Uber and Lyft representatives to a meeting at City Hall. Despite issuing dozens of warnings for violations, compliance was not improving, records show.

“This can’t keep up,” city regulator Wilson told Uber officials.

For the past two years, the city’s main tactic for identifying rule-breakers has been to order a car and conduct a surprise inspection when it shows up. The most common problem is missing logo stickers.

Uber and Lyft officials told city officials they were taking steps to address the problem.

“It is our anticipation that we should see this get significantly better,” said Clay Carroll, Uber’s senior operations manager.

A month after the meeting, Star Tribune reporters took to the streets, spending four weekends observing Uber and Lyft drivers in Minneapolis and St. Paul. Of the 300 or so drivers who identified themselves as working for Uber or Lyft, just 30 percent were using the stickers.

So far, St. Paul has not fined any Uber or Lyft drivers despite documenting at least 60 violations, including driving without a license. Minneapolis has fined a handful of drivers.

“It’s important that we make sure there aren’t incentives for bad behavior,” said Brendmoen, who co-authored the city’s ride-sharing ordinance.

Brendmoen said she’s glad that so many people are using Uber or Lyft instead of driving home after a night of drinking, but she said riders need to be aware of the risks of taking an illegal ride.

Kimberly, a 28-year-old from Eagan who asked to be identified only by her first name, said she learned the hard way.

One night last year, she spotted a car with the Uber logo after spending a few hours at the annual Beer Dabbler event at the State Fairgrounds. She asked for a ride.

The driver suggested she sit up front, she recalled in an interview, and a few minutes later he began rubbing her thigh. Upset, Kimberly asked the driver to pull into a nearby gas station. Once inside, she began “crying hysterically” and police were summoned.

Kimberly told officers she couldn’t identify the driver or his vehicle, and the investigation was closed. If she had booked through the app, police could have used the information to identify the driver.

“I have no problem riding in an Uber if I am with a friend and my friend books it through the app,” Kimberly said. “But I probably won’t drunkenly get into an Uber by myself again.”

Jeffrey Meitrodt • 612-673-4132