The Department of Transportation is inspecting city bridges whose condition is rated “poor” every three months, more than twice as often as a previous schedule required.

The transportation commissioner, Janette Sadik-Khan, said yesterday at a City Council hearing on bridge safety that the city adopted the more rigorous inspection time line “to make sure that the city’s bridges are in absolutely the finest condition they can be.” Ms. Sadik-Khan added that the city’s bridges are safe and in their best condition in generations. In 2006, three city bridges, including the Brooklyn Bridge, were given a poor rating, down from 40 in 1997; 456 bridges were given a “fair” rating in 2006, down from 530 in 1997.

The city began inspecting bridges with poor ratings more often after a Minneapolis bridge collapsed during rush hour on August 1.

Ms. Sadik-Khan drew fire from some council members for testifying that the expected implementation of Mayor Bloomberg’s congestion pricing plan would provide the city with more money to ensure bridges are in good repair. Some council members expressed outrage at the linking of the safety of city bridges to the mayor’s proposal to charge drivers for entering parts of Manhattan during designated hours.

“It is wrong to put forward that our bridges may be unsafe if not for requiring an additional tax for our taxpayers,” Council Member Vincent Ignizio, a Republican of Staten Island, said, referring to congestion pricing.