NEW YORK (AP) _ A garment truck owned by a mob-linked company sits in traffic, its horn blaring, its driver screaming. On West 37th Street, where the pedestrians move faster than the vehicles, even the Mafia has to wait.

With an average weekday vehicular speed of 2.1 mph, 37th between Seventh and Eighth avenues is the slowest street in town.

''It could be the slowest street in the country,'' says Samuel Schwartz, former deputy city transportation commissioner. ''Sometimes it's almost like you're going backwards.''

West 37th passes through the heart of the garment district, Manhattan's last bastion of manufacturing, a 20-square-block area with 5,000 businesses that design, make and sell clothing.

Because fashions can change in the time it takes a truck to move one block, the pace is frenetic, the mood volatile. Even the names of West 37th's businesses - Loadstone Inc., Flat Tire Sportswear, Wings Fashions - hint at its odd mixture of speed and stagnation.

The street is a smoky canyon of 10- to 20-story industrial buildings that reverberate the sounds of idling engines, squealing brakes and honking horns. Delivery trucks hug the curbs or double park while ''pushboys'' unload bolts of material and load on racks of finished dresses.

Pedestrians dodge easily between the mired cars and trucks, but tread carefully around the manually powered vehicles: hand trucks, dollies and wheeled racks. Salesmen, buyers, jobbers and union agents cluster on the sidewalk, schmoozing.

Halfway down the block, in the midst of this quagmire, is what at first looks like a mirage - a sooty brick firehouse.

This is Engine Company 26, whose members are resigned to the fact they will never be first at any fire farther away than the end of the block.

When an alarm is sounded on weekdays, the firefighters must 1) clear vehicles from in front of their red garage door; 2) stop traffic so they can pull the engine into the street; and 3) try to get vehicles up ahead to clear a 10-foot-wide channel for the engine.

This is even harder than it sounds, and thousands of decibels louder. It always takes the company at least three minutes just to get off the block, as much or more time than it generally takes other companies to reach a fire.

''It's frustrating,'' admits Lt. John LaPerche. ''You know you're going to a fire, but you're sitting there in traffic, and you know you're not going to get there first, even if you're first due.''

Firefighters often run ahead of the engine to clear a path through stalled traffic, and sometimes they're tempted to answer the call on foot. But, LaPerche laments, ''we can't do much without the rig.''

The firehouse predates the garment industry's move here from the Lower East Side in the 1920s. ''The problem just grew up around the house,'' LaPerche says.

Across the street, a women's clothing wholesaler says he sympathizes with the firefighters, rues their shrieking siren, and loves the traffic they hate.

''It's good for business,'' says Ori, who - like many people on the street - does not give out his last name. ''People sit in the traffic and they have nothing else to do but look at the clothes in my window. Then maybe they come back.''

The recession has reduced the flow of vehicles into Manhattan, and in the past year the average weekday speed in midtown has risen from 7.3 to 7.9 mph, according to the city.

But West 37th between Seventh and Eighth remained stuck at 2.1 mph.

City planners need to locate traffic bottlenecks, so Transportation Department surveyors track them down the hard way - by driving repeatedly down the worst blocks. On average, it took them six minutes to clear the one on West 37th.

Schwartz, the traffic expert, says the street's real transportation problem is vertical, not horizontal. Inside its buildings, 50- and 60-year-old manual freight elevators creak along at 250 feet a minute; outside, waiting trucks back up and block traffic.

In a stab at reform, the Seventh Avenue entrance to the block has been plastered with signs barring passenger cars between 10 a.m. and 3 p.m. on weekdays. Traffic officers once stood at the corner, ticketing vehicular trespassers, but budget cutbacks have stopped the patrols.

Traffic agents still stalk the street, however, ticketing cars that pull to the curb. The other day Christina Iliopoulos got a $40 ticket even though her motor was running, even though she was behind the wheel, even though she was just waiting at the curb for her mother.

''No parking, no standing, no nothing,'' said traffic agent Gabreja Josefina. ''Not on this street.''