The city shut the River Street bridge over the Amtrak and commuter-rail lines for about 90 minutes late this afternoon because of excessive vibrations motorists felt as they drove outbound from Cleary Square.
The bridge was re-opened shortly before 6 p.m. after engineers determined the bridge was safe to drive over and would not come tumbling down on the train tracks underneath. Even after the bridge was re-opened, however, a couple of highway engineers from MassDOT stood guard over the trouble area, a patch roughly three feet wide in which the asphalt had given way and the planks underneath made a clanging sound as vehicles drove over it.
Traffic was backed up on both ends of River Street, Hyde Park Avenue in both directions and on Summer Street, which parallels Hyde Park Avenue. But traffic in Cleary Square itself never reached gridlock as Boston police officers kept the cars moving. Trains along the busy tracks were ordered to slow down as they passed under the bridge.