Sunday's TD Bank Five Boro Bike Tour, which organizers expect to draw 32,000 cyclists, may cause significant delays for motorists in the city.
The 42-mile tour, now in its 33rd year, starts and ends in lower Manhattan, with cyclists crossing five major bridges.
Police advised drivers to avoid the Verrazano-Narrows Bridge, which will be partially closed Sunday until 6 p.m. After that, travel on the bridge will be fully restored.
Motorists also should avoid the RFK Bridge from 8 a.m. until 1 p.m., police said.
The Queensboro and Pulaski Bridges will be closed to motor vehicles from about 9 a.m. to about 1:30 p.m., potentially snarling traffic at the Queens-Midtown Tunnel as drivers are diverted there.
Cyclists will start the tour at Battery Park at 8 a.m. and head north on Church Street and the Avenue of the Americas into Central Park. Continuing through Harlem, riders cross into the Bronx before turning south and riding along the FDR Drive.
A detailed list of street closures is available on the city Department of Transportation's website at nyc.gov/html/dot /downloads/pdf/2010_bike_ tour_route_and_timetable.pdf.
The nonprofit organizer, Bike New York, provides a map of the bike route on its website at bikenew york.org /rides/fbbt/images/fbbt-route map.pdf.