NEW YORK (AP)  The city can force groups of 50 people on bicycles to get a parade permit, a judge ruled Tuesday in a legal clash between cyclists and police that landed in court after hundreds of cyclists were arrested when the 2004 Republican National Convention was in town.

U.S. District Judge Lewis Kaplan said he was sympathetic to cyclists’ concerns but was not persuaded by the argument that the 50-person threshold is arbitrary and lower than necessary to achieve “the city’s substantial interests in safety, efficiency and traffic flow.”

The lawsuit was brought in Manhattan by the Five Borough Bicycle Club and interested bicycle enthusiasts after more than 260 bicyclists were arrested during the 2004 convention. They said their rights to travel, expressive association and free speech were violated.

Each year, the not-for-profit bicycle club organizes about 250 group rides, mostly on weekends and holidays, that travel from 25 to 80 miles and take place at least partially in New York City. The judge noted that about 1,000 group bicycle rides occur each year in a city that has more than 100,000 riding bicycles each day on its streets.

So-called Critical Mass bike rides became the focus of a police crackdown in the summer of 2004. The bike rides started in San Francisco in 1992. Two years later, they started in New York. Now, they take place around the world on the last Friday of every month to assert cyclists’ rights and to protest urban areas’ reliance on motor vehicles.

Critical Mass rides in the city were small before thousands of people participated in a ride several weeks prior to the Republican convention.

On the eve of the convention, one of the rides became chaotic and dangerous as participants engaged in traffic violations including running red lights and taking up all lanes of traffic, Kaplan noted.

In his written opinion, Kaplan included the quote of one police officer who described it as scary, saying screaming cyclists threw things, revved their engines and lurched forward in a threatening manner toward pedestrians. “I thought we were going to have mass murder,” the officer said.

Kaplan said he remained unpersuaded by arguments that large groups of bike riders are often safer on the roads than individuals.

“Large groups of cyclists may well be more visible than individual cyclists and may take up less space than large groups of vehicles, but countervailing factors such as their lack of predictability and their tendency to try to stay together in a moving column, even if this means going through a red light, nevertheless endanger other travelers and disrupt orderly traffic flow,” Kaplan wrote.

Lawyers for the cyclists declined to comment on the ruling.

City attorney Mark Muschenheim said the city was pleased with the ruling.

“The court recognized that the policing of Critical Mass rides was not based on any attempt to infringe First Amendment rights, but rather stemmed from Critical Mass bicyclists’ lawless behavior, which included intentionally blocking traffic, riding through red lights, and cycling the wrong way on both one-way and two-way streets,” he said.