Here's a novel excuse: traffic.

According to a new study by the advocacy group Transportation Alternatives, people who live on highly trafficked streets tend to go out less and have fewer friends and acquaintances than people who live in less congested parts of the city.

Seems car horns and exhaust fumes aren't so conducive to chatting up that new neighbor down the block.

The study surveyed 450 residents in Brooklyn Heights, Astoria, Chinatown, and the High Bridge section of the Bronx in an effort to quantify the decline in quality of life caused by the growing number of motor vehicles jamming up our streets.

The preliminary findings about how traffic affects social relations and children's ability to play will be presented Wednesday night at the Municipal Arts Society (457 Madison Avenue at 51st Street), where a two-month exhibition addressing the Big Apple's love affair with the auto is underway.

"Livable Streets: A New Vision for New York," takes aim at New York's "auto-centric" grid by challenging the city, and in particular, the traffic planners at the Department of Transportation, to rethink how people use the city, and to what end.

Pedestrians outnumber car-commuters in Manhattan by more than seven to one. So how come our streets are largely devoted to motor vehicles? "Other cities have begun to measure the performance of their streets in terms of walkability or bike-ability," notes Paul Steely White, executive director of Transportation Alternatives. "Here in New York, we're still measuring by how many potholes we've filled or the 'vehicular level of service,'"—i.e., how many cars can cram down a street at any given time.

More than a design show, this exhibit, which runs through March 31, is the opening salvo in the New York City Renaissance Campaign, a new coalition of community and advocacy groups, elected officials, and business leaders who are pushing to restrict automobiles and level the playing field for bikers and pedestrians.

Cities like London, Copenhagen, Bogot