The Thayer School expansion involves a lot of changes to an entire district of the campus. Campus Services has information on the overall project.
The page describes the new Thayer School building:
The proposed building, to be located south of the Maclean Engineering Sciences Center, will be constructed over a new three-level parking garage. The garage will replace Cummings lot, and will significantly increase the number of parking spaces in this area. This project will also change the flow of traffic along West Wheelock Street and throughout the West End. Thayer Drive will close, and a new access road will be constructed specifically to provide access to the parking garage, and Thayer loading docks and the Channing Cox parking lot. Old Tuck Drive will be reconstructed and reopened to support one-way traffic heading from west to east. Improvements to the intersection of West Wheelock, West Street, and the new access road will also be made to improve access and safety of pedestrians, cyclists and drivers.
Dartmouth News has a story on the proposal for a new set of stoplights on West Wheelock Street at Thayer Drive (see also the Valley News).
We learn from the college news story that the Thayer School building “will be connected at ground level to the MacLean Engineering Sciences Center and Cummings Hall.” Presumably “at ground level” means aboveground as opposed to belowground, where the garage is. Because renderings show only a second-level bridge connecting the new building to MacLean; pedestrians will go under the bridge to follow the “Green to Blue” route. See this rendering reproduced from the latest Dartmouth Life print publication (showing the existing brick wall of MacLean in white on the right):
Incidentally, the college’s project manager for the Beyer Blinder Belle West End Master Plan was planner Douwe Wieberdink; he’s now with BBB. And the landscape architects for the West End work are Michael Van Valkenburgh Associates: perhaps one can feel a bit better about the fate of historic Tuck Drive following its partial demolition.