For Traffic Engineers, a Balancing Act : Commuting: They deal with the little things--signals, signs, turn lanes--that keep the city moving.

Commuters inched forward, part of a mile-long backup. Several drivers jerk-stopped their cars, too late to slip through the green light. One frustrated motorist in a pickup truck cut off a car, and the two drivers exchanged obscene gestures.

Nearby, a gas station operator grumbled that business was down. A traffic officer proclaimed that ticket-writing was up.

Amid the commotion at the intersection of Victory and Sepulveda boulevards last week, there stood soft-spoken Eleanor Pui Ng, stopwatch and clipboard in hand, preparing to tinker once more with the commutes of the 65,666 motorists who pass through the intersection each day.

At a time when horn-honking, fist-flailing traffic woes are a prime producer of complaints all over Los Angeles, Pui Ng is a member of a little-known but influential cadre of Los Angeles city traffic engineers who quietly spill onto the roadways each workday on a sometimes futile, occasionally victorious, mission to fix troubled streets.

“Maybe if I take two more seconds from Sepulveda it will help Victory,” Pui Ng said, eyeing the traffic-signal timer. “Maybe 2 1/2 seconds. You know, sometimes this can be very delicate. A few seconds can screw everything up.”

The traffic engineer’s judgment can alter the length of the backup on major avenues, the safety of an intersection and the profits of a business. Some residents, desperate for traffic improvements, plead with engineers for relief because their lifestyles, even their lives, are at stake.

“I take my life in my own hands when I make a turn,” wrote one resident who lives near Mulholland Drive. “We must have a left-turn arrow.”

“Customers can’t reach us because the alley is blocked off,” said David Lynch, operator of a drive-through hot dog stand, asking engineers to settle a dispute between competing restaurants.

Hundreds of similar complaints create the traffic engineer’s raison d’etre, officials said. Although the complaint-line telephone number is not publicized like a hot line, scores of residents have managed to find it, creating a citywide backlog of about 16,000 complaints that would take more than a year to work through, said Ed Rowe, general manager of the Department of Transportation.

While high-level transportation officials handle decisions on mammoth traffic improvement projects--such as subway construction, selection of rail routes and the installation of a multimillion-dollar traffic-signal synchronization program--traffic engineers most often deal in minutiae: stop signs, red curb zones, left-turn arrows, median stripes and timing of traffic lights.

In their work, they have found that the popularity of the simple street sign cannot be underestimated.

Last year, nearly 5,000 Los Angeles residents requested new street signs. About 5,700 more wanted some type of new pavement marking and about 2,000 residents requested new traffic signals.

And they all seem to want their signs, markings and signals now.

“We carry the brunt of a lot of frustrations. Some people come to us truly belligerent about things,” said Thomas Jones, a senior transportation engineer. “There is only so much we can do to make traffic flow better. I can’t promise a miracle, but we can do some good things.”

What people have trouble understanding is that raising a street sign is a complicated task. Switching on a five-second left-turn arrow can bring on a mile-long backup. Car-count surveys, geometric designs, “pedestrian-seconds” and signal cycles must be considered before any new street device is installed.

Few locales offer such a fine example of a traffic mess as the intersection of Victory and Sepulveda boulevards in Van Nuys.

For months, residents in a four-block neighborhood southwest of the intersection pleaded with the city to stop what many described as the selfish practice of speeding commuters who turned right off of Victory to take a shortcut through their streets.

“It was bedlam out there,” said Orion Street resident Kathleen Freeman. “There is no reason for a neighborhood to be destroyed so that someone can get to a job 10 minutes faster.”

The residents demanded that traffic engineers install a “No Right Turn” sign.

But first, the city had to investigate. Was there really bedlam on Orion Street? A device was laid on the road to count the number of cars. The calculator tabulated more than 800 vehicles an hour.

“That’s pretty much,” Pui Ng said.

Up went several “No Right Turn” signs to prevent motorists from turning before the major intersection at Victory. A right-turn lane was added on Victory to accommodate the 800 cars back on the boulevard each hour. A new right-turn arrow was added to help the 800 cars make it around the corner.

The result?

Smiling residents. Scowling commuters. One grumbling gas station manager who said business has dropped about 10% because customers can’t turn right into his station. And a six- to 13-minute delay eastbound on Victory Boulevard that on a bad day creates a 1 1/2-mile backup.

Pui Ng figures that she can steal two, maybe 2 1/2 more seconds from Sepulveda commuters so that two more cars on Victory can traverse the intersection each cycle.

If she took half a second more, the average pedestrian, who walks four feet per second, would not have enough time to cross Victory Boulevard.

“This intersection was like a suitcase that had been stuffed as tight as it can,” Pui Ng said. “Then someone wanted to put a pair of shoes in because it would be nice. Now you see what’s happening, the whole thing is bulging.”

To prevent the suitcase from bursting open and spilling its contents back onto Orion Street, Los Angeles police officers are ticketing “No Right Turn” scofflaws.

To be sure, the intersection of Sepulveda and Victory is an exceptional case, traffic engineer Gerald Tom explained as he drove to Pickford Street and Spaulding Avenue in the Mid-City area to make a critical, though less complex, decision.

“I just can’t justify a stop sign at this intersection. There are no blind spots and only light traffic,” Tom said, reviewing a 40-signature petition from nearby residents.

The residents wrote that they need a stop sign to “curb excessive speeds which create lethal conditions.” Tom plans to respond that a stop sign is not warranted.

Tom’s next stop was at the beleaguered intersection of Rodeo Road and La Cienega Boulevard near Baldwin Hills. One nearby resident is fed up with the time it takes to make a left turn onto La Cienega. He is demanding a green left-turn arrow.

What the resident doesn’t know is that a left-turn arrow would be likely to anger 43,361 of his fellow commuters. They would be trapped in a “big mess” because the little five-second green arrow means that every other car has to wait longer for its turn, Tom said.

“There is no magic solution,” Tom said. “An arrow would just jam everything up.”

On a quieter road, along the 12300 block of Laurel Terrace Drive in Studio City, Myrtle Jones, 82, has detected a traffic dilemma from her bedroom window.

“It’s just awful what I see,” said Jones, who uses a wheelchair and passes much of her time reading near her window. “I see (drivers) cross over that median line every day. They have taken down the lamppost and the hydrant.”

Traffic engineer Rolando Buensalida watched almost every motorist speed over the double yellow line. He measured. He sketched out street stripes. He became confused.

This was a case for the Geometric Design Team, Buensalida concluded. Traffic experts on the team use mathematical formulas to determine the configuration of yellow stripe lines.

At his West San Fernando Valley office, Transportation Engineer Raymond H. Wellbaum grappled with what promises to be the next project of Sepulveda-Victory magnitude.

He points to a stack of letters from Tarzana and Encino residents and repeats a familiar lament: “They are unhappy because traffic is clogging their neighborhood.” Motorists are avoiding congested Sepulveda Pass on the San Diego Freeway via hillside shortcuts.

As Wellbaum studied a map of Ventura Boulevard, the Valley’s notoriously congested thoroughfare, he began to mumble in traffic engineer-speak: road capacity, peak-hour restrictions, signal cycles.

A traffic engineer “can only deal with what’s physically there and operate the best he can,” Wellbaum said, walking away from the map of troubles.

Nonetheless, Wellbaum said, he will attempt “to balance the needs of the neighbors against the needs of commuters.” His determination resembles the spirit of the cartoon near his desk that reads, “Your traffic engineer is always ready to get you out of a jam.”

Never mind that the picture above the caption depicts a hopelessly gridlocked intersection.