The announcement sparked a furious reaction in Fife and Dundee, but delighted business groups in the west of Scotland.
The Executive said lifting the 60p tolls on the Clyde crossing would relieve congestion and improve air quality by diverting traffic from the toll-free Clyde Tunnel and Clydeside Expressway. The construction costs of the 35-year-old bridge have been paid off, but the move will require 4.5 million a year for its maintenance.
By contrast, Tavish Scott, the transport minister, said the 40-year-old Tay crossing had yet to pay off its capital costs, and congestion and pollution would get worse in Dundee city centre, at the north end of the bridge, without the 80p tolls. The toll booths, at the Dundee end of the bridge's southbound carriageway, may be switched to the opposite end of the bridge.
Anne McGovern, the leader of Fife Council, said: "Removing the tolls on the Erskine Bridge but retaining them on the Forth and Tay is wholly unfair and inequitable for Fifers."
However, Jim Harrold, the president of Renfrewshire Chamber of Commerce, said: "Mission accomplished! I'm delighted the minister has acted decisively."