The smart-growth urban planning fad that is sweeping the nation’s cities has taken root in Loudoun County, Virginia where the local Board of Supervisors recently passed a new comprehensive plan that rezones 205,000 acres (two-thirds of the county) for either one house per twenty acres, or one house per fifty acres. Supporters of the new plan, including the membership of the Piedmont Environmental Council, now intend to use Loudoun as a model for other suburban and rural counties in the commonwealth. These true believers preach that smart growth will create a promised land of reduced congestion and air pollution, more affordable housing, and more urban open space.

The reality turns out to be exactly the opposite. Smart growth’s prescriptions of high-density housing combined with few highways greatly increase congestion. This dirties the air because cars pollute more in stop-and-go traffic.

Smart growth creates plenty of affordable housing if you want to live in an apartment, but it prices most families out of the American dream of owning their own home. And urban open space rapidly disappears under smart-growth demands for infill development.

All of these trends are visible in Portland, Oregon, which has adopted the strongest smart-growth plan in the nation. Planners promised to save Portland from becoming like Los Angeles, the most congested, most polluted, and one of the least affordable urban areas in the country. So voters agreed to create Metro, the nation’s strongest regional planning authority.

Metro planners drew an urban-growth boundary around the region that included Portland and nearly two-dozen suburbs. Most land outside the boundary was downzoned so that people can’t build a house on their own land unless they own at least 160 acres and, if it is farmland, actually earn $80,000 a year farming it.

Metro estimated that the region’s population would grow by eighty percent over the next fifty years. To accommodate these people, Metro ordered the cities and towns inside the boundary to upzone existing neighborhoods to much higher densities.

Many cities rezoned neighborhoods of single-family homes for apartments. Zoning rules are often so strict that if your house burns down you are required to replace it with an apartment.

Portland built a light-rail line in 1986 that carries less than half as many people as originally projected and does nothing to relieve congestion. Portland’s light-rail system costs as much per mile as an eight-lane freeway yet carries fewer people than one-third of one freeway lane. Yet Metro wants to build another eighty-five miles of rail transit, while building almost no new roads.

To promote transit, Metro directed that dozens of high-density transit-oriented developments be built. Since developers knew that there was little demand for high-density housing, Metro and the region’s cities had to offer tens of millions of dollars of subsidies to promote these developments.

What is the effect of all these policies? In 1990, ninety-two percent of all travel in the Portland area was by auto, while only 2.5 percent was by transit and five percent was by walking and bicycling. Metro predicts that its policies will double transit’s share and slightly increase walking and cycling.

But that still leaves eighty-eight percent of all travel by automobile. With an eighty percent population increase and few new roads, Metro predicts that the amount of time people waste sitting in traffic will quadruple.

That’s okay, says Metro, because congestion is a sign of “positive urban development.” Metro has actually targeted most of the region for what traffic engineers call congestion level F, meaning stop-and-go traffic, because it fears that without that congestion few will ride its expensive light-rail lines.

Meanwhile, the urban-growth boundary has driven up the price of land from $20,000 an acre in 1990 to $200,000 an acre today. Before 1990, two out of three Portland-area families could afford a median-priced home. Today, less than one out of three can afford such a home.

Metro’s plans are also destroying the urban open spaces they promised to protect. To meet Metro’s density targets, cities rezoned vacant lots, urban farms, golf courses, and even a few city parks for high-density housing. When voters gave Metro $135 million to buy parks and open spaces, eighty-five percent of the land it purchased was outside the urban-growth boundary, where it was inaccessible to most people.

In 1994, Metro reviewed U.S. urban areas to see which one was closest to its plan for Portland: a high-density region with few roads and lots of rail transit. It turned out that the highest density urban area in America also has the fewest miles of freeway per capita and is building one of the most expensive rail transit networks. What urban area is that?

Believe it or not, it is Los Angeles, which turns out to be the epitome of smart growth. Metro concluded that Los Angeles “displays an investment pattern we desire to replicate” in Portland. Once again, smart growth produces exactly the opposite of what it promises.

If you want to replicate Los Angeles in Virginia, then by all means follow Portland’s smart-growth example. However, if your idea of livability is something other than congestion, pollution, unaffordable housing, and disappearing open space, then you should avoid smart growth like the plague.