Future vacations may find Harvard and Radcliffe students being blasted through an underground pneumatic tube between Boston and Washington.

Such an air propelled train was one of many possible railroads of the future envisaged by William W. Selfert, dean of engineering at M.I.T., and head of the federally financed "Project Transport."

Selfert explained in an interview yesterday that the project was intended as a preliminary study of transportation conditions in the Northeast. He said that the government is particularly interested in proposals for a high speed railroad between Boston and Washington referred to by President Johnson in his state-of-the-union address Monday.

The study is trying to remain as noncommittal as possible, according to Selfert, and is taking even the remotest possibilities into consideration. To be successful, however, any new form of transportation would have to offer both a speed and a fare comparable to those of the airlines.

"This would mean speeds on the order of a couple of hundred miles an hour at the minimum," the M.I.T. professor said. Counting time to and from the airport, this would achieve about the same speed as present air travel.

No Stops

In order to maintain high average speeds, the trains would need to be expresses, Selfert explained. The problem of getting people on and off the moving trains at intermediate stations would therefore be an important area of research.

Selfert seen one solution in trains which would be made up as they went along. A special car, for example, might be boarded at Providence, accelerate to the speed of the train and couple on as it passed. Getting off the train would be accomplished in much the same way.

Another important requirement for high speed, according to Selfert, is a very straight route. "The present right-of-way is so full of curves that you might as well forget about it," he said. The choice of a new route would depend on the kind of equipment used.

The roadbed for conventional or elevated equipment would be best located along a line some distance inland from the coast. Land would be cheaper here and special access routes could be built to serve the major cities.

Subterranean routes would require no right-of-way at all. However, with present tunneling techniques, Selfert feels that the cost of building an underground roadbed would be greater than the cost of acquiring the necessary right of way.

Any guideway used would probably have to be enclosed. Selfert said. He mentioned a high speed railroad now in use in the San Francisco Bay area.