The saturation and shift under the roadway is pretty bad. This is going to be an actual tear out and rebuild job, right down to the underlying concrete slabs. Due this, there will probably not be an opportunity to open it to one way traffic during the construction. ~ Steve

I received this update from NHDOT:

“Regarding the closure of a portion of Route 12 in Charlestown, the Department has gathered sufficient data to draft a plan for repairs. 

It is anticipated that the road will be repaired and open to the public around the end of November, 2021.The site is constrained by the railroad corridor, Connecticut River flood plain and wetlands, and utilities.  The Department has been working closely with NHDES, FHWA, and the railroad to determine the requirements for roadway repair and funding available to assist in the efforts. Our data collection is nearly complete and alternatives to reduce impacts are being investigated. Reconstruction of the roadway is required to remove compromised soils and construct a stable repair for the roadway and railroad. 

We are working diligently to prepare an emergency construction contract to bid and begin construction in early September. The work will include deep excavations, removal of the underlying concrete slabs, stabilization and strengthening of the slope, and replacement and repair of the pavement and drainage. Similarly, the Department is required to meet federal and state regulations in performing the work, and doing so in an expeditious manner. We are further evaluating the permitting and construction schedule, but estimate having the road open by Thanksgiving. ” ~ NHDOT