The state Department of Transportation announced temporary gate closings for the Route 40 and 30 bridges at the city’s edges.The Route 40 drawbridge will undergo a series of closures between 9 a.m. and 2 p.m. Friday. Each closure will last 5-10 minutes, the DOT said in a news release.On Wednesday and Sept. 24, the same closures will occur on the Route 30 drawbridge.