This week, probably tomorrow, the MBTA will release a master plan for rapid transit expansion within the Boston metropolitan area. One of the key recommendations is expected to be the extension of the Harvard Square line into North Cambridge, probably to Porter Square and then out to Route 2. And one possible route for this extension would take the subway directly beneath Radcliffe Yard and precariously close to the Loeb Drama Center.

The prospect is not pleasing: the new subway tunnel represents a threat of permanent vibration, and while construction is underway, the Yard would be a monumental mess. MBTA engineers would probably use a cut-over technique of construction through the Yard; that is, they would dig down from the surface, build their tunnel, and then relandscape the surface when the tunnel is completed.

Given these facts, the response of University officials (off the record) and Mrs. Bunting (on the record) has been both realistic and constructive. Mrs. Bunting has not pledged implaccable opposition to the roue, if the MBTA does indeed select it. What she has said is that she wants to be convinced that this is the best possible path for the subway.

There is apparently one other possibility: destroying the present tunnels under the kiosk and having the subways turn sharply at Harvard Square and swing directly up Massachusetts Ave. But this scheme involves huge engineering problems, and therefore, a considerable financial strain.

In any case, if the MBTA does select the Radcliffe route, it clearly has an obligation to do everything possible to eliminate noise, vibrations, and any other permanent effects from the Radcliffe-Loeb area (and including a small residential district between the Loeb and Mt. Auburn St.). These problems are not insoluble, and by working together Harvard and MBTA experts should be able to design the extension without permanent damage. Whatever the route choice, Harvard and Radcliffe should remain calm: by accommodating the public interest, the University is in the best position to protect its own.