RECENTLY, the Cambridge City Council voted to join a citizen group's suit demanding an injunction against extension of the Red Line through Harvard Square by the Massachusetts Bay Transit Authority (MBTA). The council's vote, indicative of the growing sense of frustration felt by some Cambridge leaders, residents and businessmen, appears to be a well-directed step to ensure that citizens' views are not diregarded in the extension process.

Clearly, Cambridge has a lot to complain about. The MBTA's practices over the past few years in Cambridge have been questionable at best. Specifically, the community has been misled as to the types of construction the MBTA will use, the overall impact on Mass. Ave. businesses and traffic patterns and the planned use of various public facilities.

What is at issue is the possible transformation of an area which has remained unchanged for more than a generation. Because such arguments are absract, the fight has necessarily been shifted into the courts.

The legal issue centers on an environmental impact statement (EIS) which was prepared when the MBTA planned to extend the Red Line to Rte. 128. The MBTA claims that this impact statement can be applied to its current extension project, even though the line is planned to go only as far as the Alewife Brook Parkway.

The citizens charge the MBTA with violating three federal statutes in attempting to apply the old statement to the new project. The MBTA, on the other hand, argues that any delays in construction--which a court battle necessarily implies--will mean losses of $3 million a month and jeopardize nearly half billion dollars in federal funds earmarked for the extension project.

It is time for the MBTA to stop making dire predictions and launch a supplementary EIS on the changed extension plans before a federal district court orders it to do so. This process would allow Cambridge residents and businessmen to have imput into the project while helping to insure that the extension will run smoothly if hte project is allowed to begin. Regardless of the outcome of the EIS--whether the extension is found to be environmentally safe or not--the interests of the community should be met in the process.