BOSTON – Massachusetts transportation workers on Friday removed seven additional light fixtures from the Tobin Bridge a day after one fell onto the road.

The lights were removed after a physical inspection found three with signs of corrosion and four needing new bulbs, Transportation Department Secretary Richard Davey said. Eighteen light fixtures were inspected.

He said all the lights, which were installed in the early 1990s, will be replaced in the coming months.

The inspection also found that three supports for the light fixtures’ electrical apparatus were loose due to rust. They have been reinforced, Davey said.

Officials confirmed Thursday that one of the bridge’s lighting fixtures fell about 20 feet onto a traffic lane on Route 1 in Charlestown. A police officer found the 10- to 20-pound fixture in the traffic lane around noon. The fixture fell due to corrosion and age, said officials. It did not cause any damage or injuries.

Davey said he was surprised the spotlight-style light fixture fell, but was relieved it did not land on one of the 70,000 to 100,000 vehicles that cross the bridge each day.

The Tobin Bridge, near Boston’s North End, connects the Charlestown neighborhood and Chelsea. The lights were last inspected in September 2011.