Peter Blake, author of the controversial bestseller God's Own Junkyard, called for a moratorium yesterday on all superhighway construction in the Boston metropolitan area until a long range masterplan has been developed for the city and its suburbs.

"The time has come for our cities to be shaped, not by highway engineers, but by urban designers and planners who start with the human needs of cities and then subordinate all the services required--including superhighways--to those human needs," he said at a press conference.

Blake, who is managing editor of Architectural Forum, was in Cambridge at the invitation of Edward L. Bernays, the founder of the Emergency Committee to Save Memorial Drive. God's Own Junkyard is an attack on the "planned deterioration of America's landscape."

Declaring that he was "delighted that it may not be too late to prevent the destruction of your Memorial Drive waterfront," Blake maintained that river banks and waterfronts are "desirable assets for a city."

"It seems to me it is more important for people to get to the water than to have cars running up and down a highway," he said.

From his experience, Blake observed, the construction of underpasses along Memorial Drive would probably lead to the eventual widening of the roadway into an expressway. He explained that small changes attract more cars, which create new and larger traffic problems and finally induce more extensive alterations.

Blake singled out highway planners for special criticism. "We can no longer afford to have our cities, in effect, shaped or mis-shaped by technicians whose sole interest is getting so many thousands of cars per hour from one place to another."

"Their power is now so vast," he continued, "That once they have built their super highway in a wrong place--as they propose to do in Cambridge--no amount of urban design, however inspired can possibly erase that mistake."

Transportation problems must be solved, Blake said, through coordinated planning among different highway-building bureaus and other transit agencies. Such cooperation is not wide spread today, he noted. He emphasized, however, that all transportation solutions must be tailored to the overall priorities of urban design.

After the press conference, more than 60 people, including several state legislators from Cambridge and a number of city councillors, flocked to Bernays' home to hear Blake.