Traffic? What Traffic?

Braced for weeks for possible turmoil and traffic gridlock, this city instead sailed through the first day of the Democratic National Convention.

Boston experienced virtually no reported crime on Monday and roads were unusually clear. Even the weather cooperated, with blue skies and none of the oppressive humidity generally associated with Boston summers.

“It’s just glorious,” said Nick Bigney, who cruised into Boston Harbor on Monday with his family aboard their 38-foot sloop, Rubicon. Bigney said that Coast Guard and Boston police vessels were lining the harbor “like little dominoes,” but that they did not hamper navigation.

After months of dire prognostications, the uneventful debut of the city’s first national political convention brought inevitable comparisons to the 1984 Summer Olympics in Los Angeles, when traffic flowed smoothly, crime dropped and smog abated.

The only arrest in Boston in the first 24 hours of the four-day convention was made by the National Park Service, not the police, said Boston police spokeswoman Beverly Ford. The arrest Monday was unrelated to the convention, she said.

Helicopters hovering over the convention site at the FleetCenter were not called into action. Demonstrators in a fenced-off protest zone near the arena adhered to a strict speaking schedule without incident, officials said.

Traffic on major roads around Boston was unusually light Monday, said dispatcher Scott North of the Massachusetts State Police. Although 40 miles of highways, bridges and tunnels were shut down at 4 p.m. when the convention officially opened, the area’s thoroughfares did not turn into a gigantic parking lot, as many commuters anticipated.

“That has not been the case,” said North. “All the roads are very light. But remember, this is Day One.”

Rather than bringing their cars into Boston on Monday, Joanne Vitale and Jo Ciulla walked from their homes in Charlestown, just north of the city, to get close to the convention action.

“Today was fantastic,” Vitale said. “There was no disruption. None.”

Companies such as Gillette, one of Boston’s largest employers, rearranged convention-week schedules so many workers could end their days at 3:30 p.m., before road closures. Corporate spokesman Eric Kraus said many Gillette employees took vacations or made plans to work in locations outside Boston.

A quarter-mile from the convention site at Boston’s FleetCenter, Massachusetts General Hospital changed appointments and clinic hours to get as many day patients as possible out of the hospital by 2 p.m., director of police and security Bonnie Michelman said.

Michelman said the city’s largest nongovernmental employer spent more than a year planning for the convention. Among other accommodations, Michelman said, about 700 employees of Massachusetts General gave up their assigned parking spaces in lots near the FleetCenter so media trucks could use the space.

Despite the deluge of 35,000 delegates, party officials and media representatives, some local businesses suffered because so many Boston residents heeded warnings about traffic and stayed out of town Monday.

“Our business is down by half, if not less,” said John Caparella, owner of Mother Anna’s restaurant in Boston’s North End, not far from the FleetCenter.

“It stinks,” he said. “Usually we have too many people -- with cars backed up and everybody honking at each other. Right now, we definitely don’t have that problem.”