Standard&Poor's Ratings Services assigned its 'A-' rating to Mid-Bay Bridge Authority, Fla.'s senior-lien revenue bonds, series 2004A and 2004B. The rating reflects the following credit strengths: The Mid-Bay Bridge's strong historical growth in traffic and revenues, evidenced by toll revenue traffic growing 8.8%, on average, from fiscal year ending Sept. 30, 1998, through 2003, while toll revenue has grown 9.8%, on average, over the same period. The Florida Department of Transportation's (FDOT) commitment to pay annual bridge operating and maintenance costs as long as bonds are outstanding pursuant to an irrevocable lease purchase agreement between the authority and FDOT. Sound coverage of senior-lien annual debt service with pledged revenues, along with additional liquidity provided from $6 million held