ON THE FLOOR of the Cambridge City Council's chambers, there is a massive table where City department heads sit when the Council grills them. Come into the chambers during the Council's meeting on Monday and, likely as not, you'll see Robert E. Rudolph, the Director of Traffic and Parking, sitting behind the table sometime during the afternoon.

The Council's interrogations of Rudolph are so frequent that they've become stylized. The Traffic Director walks in, hitches up his trousers, puts his briefcase on the floor, and nervously lights his cigarette. His eyes dart first toward the Mayor's chair and then over to his left, where Councillor Alfred E. Vellucci sits.

His finger waving, Vellucci opens fire: "Mister Rudolph, we held up that money so you could come in here and tells us about," the councillor pauses for emphasis, "WIN-sor Street." Heavy traffic on Windsor was Vellucci's opener last Monday, but the councillor soon moved on to other favorites--a stop sign at 4th and Hurley, a traffic light at 6th and Gore. After a while Vellucci got tired and said "I have a big long list, but I'll save it for another night when we'll make you the big star here." Rudolph was lucky that time; only one other councillor quizzed him about traffic problems. Sometimes every one of the nine councillors takes his turn with Rudolph, grilling the Traffic Director about problems in his particular bailiwick.

Throughout the sessions, Rudolph keeps repeating: "I'll try it if that's what you want, sir," or simply, "Yes sir." His silver pen makes notes of the Council's requests in a black book. If the Traffic Director has the men and money, he acts on the problems; otherwise, they remain until the next go-around drags them up again.

The hours spent listening to the Council represent only one of the many headaches which Rudolph must endure to earn his $16,000 yearly salary. If the street patterns of Cambridge were planned at all, they were planned by a disciple of Jonathan Edwards bent on bequeathing a tangled hell to latter-day Cantabrigians. The streets are often narrow, and they careen into each other at odd angles, forming the squares which dot the map, and clog the traffic. Besides residents and students, floods of commuters from neighboring cities--such as Somerville and Watertown--use the streets on their way in and out of Boston. The numerous construction projects of the universities and private firms often make temporary changes in the traffic patterns necessary.

FACED with these probably insoluable problems, Rudolph must sometimes wonder why he came to Cambridge from Baltimore some six years ago. Since then, he's tinkered endlessly with various traffic patterns in a Canute-like struggle against the cars. One such experiment was his new Harvard Square traffic pattern which began last summer. Under pressure from the Council, Rudolph axed half of this new pattern, but kept the rest, mostly the one-way traffic on Mass. Ave. and Mt. Auburn St.

The Traffic Director insists that even the abbreviated pattern has helped traffic flows around Harvard, but critics feel that cars, even if they move faster for awhile, still get caught in the same old bottleneck in Harvard Square. Complaining letters flow in the Cambridge Chronicle. Even poets take their crack at Rudolph. In April, a poem by a senior citizen and longtime Cantabrigian" appeared in the Chronicle. In this poem Paul Revere, on a second ride, got lost in the Traffic Director's latest pattern. Rudolph was moved to respond in kind, and an exchange of poems began in the paper. The Traffic Director's latest work ended like this:

The red bloods are jammed through the mains

So the blue bloods won't get hurt in the veins

Show the blue bloods that they

Should instead lead the way

And relieve the reds of their pains.

The new Harvard Square pattern stirred up more than letters and poems. For a while, it looked as though the Council might ask the City Manager to fire Rudolph. That, and holding up appropriations, are the only weapons which the Council has against the Traffic Director, who is actually under the sole control of the City Manager. But the crisis has apparently passed, and Rudolph still has his job.

Despite the outward emnity between the Council and Rudolph, he actually performs a valuable service for them--taking the heat of citizen complaints. Some years ago--before Rudolph's time--the Council had direct control over traffic problems. "Sometimes they loved it. They were close to the people. They'd spend hours arguing over where to put a traffic light," one longtime Council observer recalls. But the votes gained from citizens who had a new traffic light near their home were balanced off against the votes lost when somebody didn't get the light he wanted. That, and the growing complexity of Cambridge's traffic problems, led to the present set-up whereby councillors can take most of the credit for a new traffic light and ease off complaints onto Rudolph's square shoulders.

SO, RUDOLPH'S weekly beatings from the Council are mostly show. They give the councillors a little space in the Cambridge edition of the Record-American. Constituents rest assured that their representatives are looking out for their best interests in the traffic department. It's pretty cozy, so comfortable in fact that a Vellucci motion to put traffic problems directly under the control of the City Council and the City Manager has lain on the table for over a month. Someday, the Council and the Manager may agree to fire Rudolph; but, even if they do, another man will probably fill his lightning-rod role.

Right now, firing Rudolph doesn't appear to be in the cards. His sessions with the Council even appear to be getting a little shorter of late. But angry citizens caught in the waves of Cambridge traffic still call City councillors to complain, so Robert E. Rudolph will still spend a lot of time behind that big table in the Council chambers.