LODZ, Poland — People drag-race on the main avenue here in broad daylight, and the police just stand by and watch. That is, until the commissioner steps up to hand trophies to the winners.

Gleaming BMW M3 sports cars mingle with souped-up speedsters incognito in the form of stubby Fiats — and everything in between. “Are you kidding me? Suzuki never made a blue engine,” one of the organizers shouted, after popping a car’s hood during the prerace inspection.

A newly flush Poland has a new hobby, cars, and the faster, the better. Nowhere is that more clear than here in the country’s second most populous city, where municipal officials struggled in recent years to deal with an explosion in the number of illegal races on public streets and a raft of complaints from residents nearly driven off the road by them.

“You have young people with powerful machines that until recently older people would have to work their entire lives to afford,” said Jaroslaw Woloszynski, the police commissioner. The police said cracking down on the activity was difficult, because racers would just stop their cars when officers arrived; handing out a few tickets for violations was usually the best they could do.

As a result, municipal leaders in Lodz (pronounced “Woodge”), deciding that if you can’t beat them, organize them, set up events in which proud car owners, overwhelmingly young and largely male, could challenge one another head to head over a quarter-mile of closed road downtown. The city government even spent close to $20,000 to buy timing equipment, with the local emergency services providing fire trucks and ambulances free of charge.

On a recent Sunday afternoon, thousands of people turned out to watch the organized races, called Street Legal, with the earsplitting roars of tuned-up engines and the brimstone scent of speeding tires. The monthly events, which are open only to local residents, have made Lodz’s racers the envy of others in Poland and earned the city the unofficial title of the country’s street-racing capital.

“Because we were christened the capital of street racing, we decided to live up to the name,” said Lech Ryszewski, 60, chairman of the Lodz Automobile Club and a former rally driver and stuntman.

“The Polish soul has always been drawn to horses,” he said, citing the country’s proud cavalry tradition, “and today it’s horsepower.”

A generation ago, Poles living under Communism had to wait years to own a car, if they were ever able to. The changing of the guard politically made automobiles more widely available, but they were still out of reach financially for many families. Poland’s recent economic success, coupled with the ease of importing used cars from Western Europe since the country became a member of the European Union in 2004, has meant a surge in car ownership.

Mix in a stronger currency, rising employment, higher wages and expansion of consumer credit, and the car has gone from being a luxury to an expectation. The number of motor vehicles on the road grew from 9 million in 1990 to 18 million in 2006, according to a report commissioned by the Polish Automotive Industry Association. And last year more than 1.25 million additional passenger cars were registered in the country, whose population is about 39 million.

In an echo of Communist times, the lines at the car registration office here in Lodz grew so long last year that a group of men actually started a business of standing in lines for money — until the overwhelmed motor vehicle officials adjusted to the new pace. Across Poland, it is difficult to find a major road without cars bearing telltale blue signs on the roofs: an “L” for student driver.

Poland’s latest hero is Robert Kubica, the country’s first driver on the prestigious Formula One open-wheel racing circuit. But Poland still lags behind its more affluent neighbors, with few tracks and ragged roads. To reach the highest levels of auto racing, Mr. Kubica had to leave Poland and move to Italy.

At a promotional event in Warsaw last month that drew 70,000 spectators, Mr. Kubica said there were not enough tracks and organized races for young drivers with ambitions to become professional racers. “We don’t have the circuits for them,” he said. “They don’t have the possibilities yet.”

So young Polish racers turn to the streets instead. In Lodz, groups with names like Storm Riders, Red Line Racers and Night Crazy Drivers were holding impromptu racing events, with no guardrails to keep spectators from crowding the roads as the cars hurtled past.

With so many new drivers on the overcrowded roads, and the young racers also present, safety had become a huge concern. The industry association’s report found that in 2007 there were nearly 50,000 road accidents in Poland, and 5,563 fatalities. “Every eighth victim of a road accident in the European Union dies on Polish roads,” the report said. Poles account for roughly one in 13 people in the union.

So officials in Lodz tried a different approach. They decided to “hold out our hands” to young people, Mr. Woloszynski, the police commissioner, said.

“We just want to let people go fast and let them do it safely,” he added.

The first legal drag race took place four years ago. It was considered a moderate success and became an annual event, but it did not really change driving habits. This year the police joined forces with the automobile club and a group of racers from the illegal racing scene. With money from the city for the timing equipment, they started holding races monthly, starting on Valentine’s Day.

Members of the Street Legal group said the public races were great for the drivers and the city, and they said they, too, appreciated the safety precautions.

“When we were racing illegally, we had people who could come out in front of the car,” said Viper, one of the organizers, a 26-year-old whose real name is Lukas Wozniak.

Dressed all in black on a scorching afternoon, with spiky blond hair and a beard tracing his jaw line, Mr. Wozniak looked as if he had stepped out of the movie many of the racers claim as their inspiration, the 2001 American film “The Fast and the Furious.”

Unlike the flashy cars in the movie, many of those in the Lodz competition are unassuming. But the VW Golfs or Honda Civics roar like lions at the starting line, overpowering the kittenish purr of brand-new, factory-built sponsor cars in demo duels before the main event.

Marcin Madry, another of the Street Legal organizers, said car-tuners in Lodz were known for emphasizing speed over style, while in some other Polish cities — he mentioned Poznan — owners put more energy into style, or what they call “optic” modifications.

Mr. Woloszynski said illegal racing had been reduced by 80 to 90 percent. A hard-core racer who is a member of one of the local clubs, who did not provide his name for fear of unwanted attention from the police, said they were still out racing illegally at night.

Indeed, Mr. Ryszewski, the chairman of the Lodz Automobile Club, said several drivers who wanted to compete in the legal races had been suspended from them after undercover officers caught them on camera in illegal races in March. But all sides agreed that there was far less illegal racing since the sanctioned competitions began, particularly among the dangerous novices.

“You’ve got different types of people,” said Pawel Zel, 21, a bartender watching cars whipping past at the races.

“Some want the adrenaline rush of racing. Some want the rush of breaking the law,” said Mr. Zel, who acknowledged that in the past he had participated in illegal street racing. “There’s far fewer people who actually race illegally now.”

Arkadiusz Kubiak, who was the winner in the highest of six categories of cars, based on engine size, said that he would not deny that he had raced illegally in the past, but that those days were over for him.

“When driving illegally, it’s in the dark, it’s dangerous and you can’t measure the time,” Mr. Kubiak said.

He said he had spent more than $10,000 fixing up his car, a Mitsubishi — more, he said, than he had paid to buy it — and had done all the work himself, except for the electrical system.

“Knowing you’re the fastest driver in Lodz?” he said. “It feels great.”