Sooner or later, we all may have to come to terms with Los Angeles, which could prove to be the urban model of the future, even for metropolitan Washington.

Along with several other University of Maryland architecture faculty members and students, I just completed a five-day, nonstop Los Angeles odyssey, an attempt to get better acquainted with the realities and myths of this sprawling, gaudy, animated city.

I was tempted to dig deeper into Los Angeles' architectural forms and fantasies because we in the East so often cite that city, almost by reflex, as the kind we don't want but nevertheless seem to be building.

Of course, there are significant differences between Los Angeles and Washington, ecological contrasts being among the most apparent.

Los Angeles' climate is hot and arid, its plains and hills part of an irrigated desert abutting the Pacific Ocean. Adding water year-round to its dry but fertile soil produces incredibly lush, tropical vegetation that looks all the more colorful and succulent in the otherwise scrubby, brown and gray landscape.

By East Coast standards, Southern California has just one season, an amalgam of spring and summer. Although one might miss the variety of conifers and deciduous trees dominating this region, one might like the West Coast weather -- it doesn't snow or freeze in Los Angeles.

This not only allows outdoor living much of the year, but it also puts little stress on streets and structures, some of which seem little more than giant, stuccoed cabanas. The lack of climatic extremes makes it possible to build homes and roads on steep hillsides -- at the risk of succumbing to earthquakes and mud slides -- that would be impossible here.

One other notable environmental difference between Los Angeles and Washington -- at least for now -- is air quality. Los Angeles is still plagued by smog, despite pollution controls on cars and industries. Washington has little industry, but its car count is rising fast.

Of course, Los Angeles and Washington have different reasons to be. The District is the nation's capital, an administrative city full of politicians, civil servants, lawyers and lobbyists. Only in recent years have high-tech service industries arrived and grown, mostly around the Capital Beltway, to complement Washington's governmental industry.

Los Angeles' economy is more diverse than Washington's -- it has more heavy industry -- but its popular image as the entertainment capital of the world still prevails.

Thus, although both cities are capitals in one sense or another, most of Washington's citizens and institutions are quite restrained in their tastes and behavior while much of Los Angeles' citizenry inclines toward the offbeat, the flamboyant, sometimes the bizarre. A bit of Hollywood infects all of Los Angeles; Potomac propriety is more the Washington style.

Los Angeles and Washington have very different city plans. Washington's baroque pattern of relatively small blocks is woven together -- and regularly interrupted -- by diagonal avenues, squares and parks overlaying a tight street grid. The L'Enfant plan was predicated on imparting a strong sense of civic form transcending the surveying and subdividing of undeveloped real estate.

Like most newer western cities, Los Angeles clearly has a surveyor's plan. It consists of a grid pattern, but with much larger blocks and wider streets mostly aligned east-west and north-south. The major streets became the city's commercial strips. Within the large blocks, further subdivision created smaller residential blocks.

Today, greater Washington still has a distinct center -- the District with its downtown, the Federal Triangle and Mall, the surrounding urban neighborhoods of Georgetown, Capitol Hill, Dupont Circle and, across the river, Alexandria and Arlington. This remains the region's symbolic and functional core, connected by perhaps the world's most attractive subway and park systems.

Los Angeles today has no such core, even though it has a so-called downtown full of skyscrapers. Greater Los Angeles is an outstretched tissue of neighborhoods and mini-cores mapped onto numerous, disparate political jurisdictions covering several hundred square miles.

The only physical connections are overloaded freeways and commercial strip roads. You move around Los Angeles entirely by car, even for traveling relatively short distances. Forget bicycles and walking.

Los Angeles has become a city of many little centers, its fringes a maze of subdivisions, shopping malls, office buildings and retail roads lined by parking lots. It's the result of seemingly endless supplies of cheap land and gasoline, unregulated growth and real estate speculation, and an acceptance, if not a desire, by many Californians to live in a city of dispersal. Sound familiar?

If you work and live in one suburban community, and if you don't feel the need for a dominant city center like Washington's, then the Los Angeles model is undeniably attractive.

In this sense, metropolitan Washington is only several decades behind Los Angeles. In the next half century, an urbanized greater Washington could stretch continuously from Annapolis on the east to Howard County and Frederick in the northwest, from Maryland's Charles County on the southeast flank around to Virginia's Prince William and Loudoun counties in the south and west.

Looking at a map shows that this emerging regional city is easily comparable in size to greater Los Angeles. Likewise, a future greater Washington could match the population and automobile dependency of Los Angeles.

Because of the Metro and growth, Washington's existing inner ring of subcenters -- Silver Spring, Bethesda, Rockville, Tysons Corner, Alexandria -- soon will feel even closer than before as residential and commercial development penetrate farther into outer rings of cheaper land.

In 50 years, more and more people will claim to be residents of greater Washington but, like residents of Los Angeles, may never go "downtown." As in Los Angeles, more and more people will drive more and more cars unless, somehow, a regional mass transportation strategy for the coming century is hammered out soon. In 2020, it might take hours to drive across or around greater Washington.

What is most convincing about the coming of Los Angeles to Washington is seeing how alike, despite all the ecological differences, new development looks around each city. Subdivisions, streets, parking lots, office buildings and overall densities are surprisingly similar. There are the same national chain stores, franchises, fast food outlets and signs everywhere. Regardless of architectural contrasts, one feels immediately at home, secure with the familiar, no matter where or how far one goes.

Could the Los Angeles model be okay? If it's so ubiquitous, perhaps it's the true expression of what we want, or of what our system inevitably produces.

Yet we could build in Washington a better version of Los Angeles.

We could insist on rational, form-giving order -- with public as well as private space -- in laying out new communities.

We could control and coordinate regionally the rate and location of growth, more effectively managing public resources and infrastructure.

We could change travel habits, aiming for a better split between private cars and public mass transit.

And we could reinforce both the perception and reality of the District as the uncontested central core -- for business, culture, government -- of greater Washington.

It's not too late to learn from Los Angeles, but it soon could be.

Roger K. Lewis is a practicing architect and a professor of architecture at the University of Maryland.