Officials with the Massachusetts Department of Transportation are planning to close the Rte. 99 underpass on the northbound side through Charlestown's Sullivan Square starting Monday, June 16.
The closure is due to ongoing $56.1 million reconstruction of the Alford Street Bridge that connects Charlestown and Everett, a project that is expected to be completed by the end of August, MassDOT said in an announcement last week.
The route will be closed for about six weeks, but will not affect traffic traveling in the southbound direction of Rte. 99; during the closure, northbound vehicles will instead access Rte. 99 through Sullivan Square, according to the announcement.
Traffic on the bridge, meanwhile, will be shifted so that vehicles traveling northbound toward Everett will be moved toward the east side of the bridge, while vehicles traveling southbound toward Charlestown will remain on the west side of the bridge, MassDOT said.
Moreover, one travel lane will remain open at all times in each direction during construction, and implementation of the shift may be postponed due to weather conditions.
Drivers in the area are asked to seek alternative routes to avoid delays during the six-week period; drivers that need to travel through the area can expect delays and will need to reduce speed while moving through detour routes, MassDOT said.