RUTHERFORD, N.J. -- It is 4:01 p.m. at Shadow Traffic Network and Fred Bennett's headset is buzzing with bad news.

A school bus accident has snarled traffic along Flatbush Avenue. A disabled tractor-trailer is tying up the Bronx-Whitestone Bridge. Another truck accident is blocking an entrance to the George Washington Bridge. Five minutes later, the Manhattan Bridge is packed after being closed while President Bush's motorcade carried him to a GOP fund-raiser at the Waldorf.

Bennett, operations manager for a firm that provides live reports to 62 area radio and television stations, alternately works the phones and takes two-way radio reports from six aircraft and 40 cars, furiously typing each tie-up onto a color-coded computer screen.

At 4:37, helicopter pilot Bob Glantzberg reports that construction is causing bumper-to-bumper traffic on the Van Wyck Expressway. At 4:57, things look bad on the New Jersey Turnpike. At 4:59, Glantzberg's voice crackles over the headset with word of yet another accident, this one causing a standstill on the Brooklyn-Queens Expressway. Bennett's computer screen is full.

Shadow Traffic's far-flung network provides minute-by-minute confirmation of what anyone who drives in and around New York City already knows: The place is a commuter's nightmare. With 900,000 smoke-spewing vehicles crawling into Manhattan each weekday morning -- 25 percent more than a decade ago -- traffic routinely backs up at the 20 bridges and tunnels connecting the island with the rest of the sprawling tri-state area.

By one estimate, New Yorkers waste 50 million hours a year stuck in traffic. Eleven million cars compete for space across the 31-county region, a number that is expected to jump to 16 million within 25 years.

Things have gone from awful to absurd recently as a spate of construction projects has further constricted the aging concrete arteries that bind the region. Two lanes on the FDR Drive, Manhattan's main north-south highway, were closed this month for a reconstruction project scheduled to last three years. Two lanes were shut down last month on the Queensboro Bridge, where endless construction has tied up traffic since the early 1980s.

Repaving on the Long Island Expressway approach to Manhattan will last until 1995; work will continue on the Brooklyn-Queens Expressway through 1994. From cable repairs on the Brooklyn Bridge to nighttime work on the George Washington Bridge and Lincoln and Holland tunnels, the list seems endless.

"There is no off-peak period any more," said former city traffic engineer Samuel Schwartz, who writes the "Gridlock Sam" column for the Daily News. "We've moved into a dimension of round-the-clock rush hours. We're condensing 50 years of construction work into 10 years."

The reason for the jackhammer pace of construction is that the city's highways and bridges are falling apart. Local officials plan to spend $3 billion during the 1990s, most of it federal and state money, just to keep open the same basic system that carried about half as many cars into Manhattan during World War II.

"This construction is necessary because we have the oldest infrastructure in the country and it's been subjected to years of neglect," said Joe DePlasco, spokesman for the city's Transportation Department. "Many of these facilities are in very poor shape. Most of the highways are approaching 50 years old; many of the bridges are approaching 100 years old. Some of them haven't been painted for years."

The price of bottlenecks -- from Montclair in New Jersey to Montauk on Long Island -- is more than just frayed nerves and increased air pollution. "It's definitely a drag on the economy: time wasted in traffic, wear and tear on roadways, the very high cost for truckers trying to get goods in and out of the area," said Mary Rivers of the Regional Plan Association.

The danger level is also increasing. Last year, a 500-pound slab of concrete fell from the FDR Drive, killing a Brooklyn dental technician in his car, and part of the Manhattan Bridge was closed after two support beams rusted through.

In 1988, the Williamsburg Bridge was closed for a couple of months for safety reasons a year after two 30-pound steel bars fell from the bridge into the East River. In 1982, part of the West Side Highway collapsed. A year earlier, a Japanese photographer died after being struck in the head by a 600-foot cable that snapped on the Brooklyn Bridge.

Thanks to New York's seaside geography, traffic is constantly snarled at toll booths, where drivers pay up to $5 for the privilege of transversing rivers and bays. The gridlock even extends to the skies: Flight delays soared 111 percent at LaGuardia airport and 52 percent at Kennedy last year.

Remarkably, only 16 percent of the 3.4 million daily commuters converging on midtown Manhattan arrive by car or taxi, compared to 60 percent by subway and 23 percent on buses and commuter trains. Yet despite years of official hostility to the automobile ("Don't Even THINK of Parking Here"), a tripling in the number of parking tickets and $32-a-day midtown garage fees, still more commuters are hitting the highways. Others are fleeing the subway system -- where ridership is down 6 percent because of rising crime and higher fares -- for such alternatives as express buses and private car services.

"We were the most adept in the country at squeezing more and more cars into a shoebox, but we ran out of tricks," Schwartz said. "People are going to be leaning out their car windows and screaming."

Suburban job growth and real estate inflation have also turned once-rural highways into parking lots as waves of homeowners move deeper into remote communities. The Long Island Expressway, designed to serve 80,000 vehicles a day, now carries about 180,000.

Back at Shadow Traffic's 9th-floor headquarters in the New Jersey Meadowlands, it is 6:21 p.m. and the blizzard of bad news continues: bumper-to-bumper on the FDR; thirty-minute delays at the Queens-Midtown Tunnel; 15-minute wait at the Lincoln Tunnel; car fire on the Long Island Expressway. Even the "experts" can't escape.

"I used to be able to leave the house at 6:30 {a.m.} and not hit any traffic," said operations manager James Walling, who drives 43 miles from the Jersey Shore. "Now I have to leave at 5:45 or 6. You have traffic jams at 6:30 in the morning."