When you think about streets, chances are that you think about automobiles, commuting, speed limits and parking meters. In your mind, traffic congestion and road network capacity may be the No. 1 urban design issue. Concern about automotive travel convenience may outweigh any anguish you have about the visual quality of streetscapes and roadways.

Few citizens protest publicly the questionable character, the ugliness and disorder of the routes they frequently or repeatedly follow. But if there are too many cars on such routes, if it's bumper to bumper before, during and after rush hours, then people eagerly find and sacrifice time to appear at hearings or to write indignant letters to government officials.

There's no denying that traffic congestion is a vexing and critical problem. Yet while addressing the needs of the automobile, people should also think about the character of the street space created to accommodate them. Given the amount of time that many of us spend driving, why shouldn't we at least have something nice to look at?

Some well traveled roads are memorable. Integral to the physical image of the cities or suburbs of which they are part, they can be as much an artifact to be appreciated and preserved as are single buildings, monuments, plazas or parklands.

Connecticut Avenue, one of Washington's most intensely used roads, exemplifies a street that does more than just facilitate the movement and parking of cars.

It begins at the northwest corner of Lafayette Square, but is interrupted after one short block by Farragut Square. Many people incorrectly assume the intersection of Connecticut, K and 17th streets, the northwest corner of Farragut Square, is the terminus of Connecticut.

The avenue continues to Chevy Chase Circle at the D.C.-Maryland line, temporarily departing from its original alignment once. Between Florida Avenue and the bridge over Rock Creek Park, it inflects slightly eastward and then returns to its original alignment.

Downtown, Connecticut Avenue is like other downtown streets, lined by latter-day office buildings with ground-floor retail shops or restaurants. But as it approaches and passes Dupont Circle, where there is an underpass for those in a hurry, its character changes radically.

Buildings are lower, many of them stately, turn-of-the-century row houses now dedicated to commercial use. The avenue seems more European, more Parisian, having a "boulevard" feeling and scale. This is imparted by street trees, street lights, commodious sidewalks, colorful and well-lit display windows, indoor-outdoor cafes and doorways leading to narrow stairs serving office levels above ground-floor shops.

Crossing Florida Avenue, the original boundary of Pierre Charles L'Enfant's plan for the city of Washington, Connecticut's eastern edge loosens momentarily where the Hilton Hotel claims its spacious triangular site. The avenue rises, reminding you that this is the gentle escarpment that influenced L'Enfant in determining Washington's perimeter and the alignment of Florida Avenue, which originally was named Boundary Street.

Here begins Connecticut's brief encouter with the Kalorama area, and here are the first of a series of elegant apartment buildings fronting the avenue, many of which were built in the good old days before 1929. They seem to be well situated, signaling the transition between the 19th-century city and the city that grew up beyond Rock Creek during this century.

North of the bridge and Calvert Street, Connecticut is flanked by a mixture of gigantic hotels and low- to medium-rise buildings containing shops, offices and apartments. This marks the beginning of a fairly consistent avenue land-use rhythm alternating between apartment and commercial buildings. The alternating pattern helps define the avenue's character all the way to Chevy Chase Circle.

In fact, D.C.'s zoning map reveals that Connecticut Avenue is unique in manifesting this pattern. Five distinct, linear segments of retail and commercial zoning alternate with four longer segments of mostly-high-density apartment zoning.

The commercial segments cluster in the Calvert Street area, in the Cleveland Park area between Macomb and Porter, in the Van Ness area immediately south of Nebraska Avenue, and in the last few blocks below Chevy Chase Circle. Van Ness is the largest and densest of these, including in its neighborhood the Intelsat building, the University of the District of Columbia, several office buildings and dozens of stores.

By contast, the shopping area near Nebraska Avenue is much smaller and less dense, intended primarily to serve the surrounding community. The Van Ness portion of Connecticut, while catering to local needs, constitutes a regional activity center, like a minidowntown. Not surprisingly, it can be one of the places on the avenue where traffic gets bottlenecked.

In between these five commercial nodes of varying scale are some of Washington's most magnificent apartment buildings. Only the most oblivious driver could fail to notice these grand structures lining both sides of Connecticut, especially between Woodley Road and Macomb Street, between Porter and Tilden streets, and north of Albermarle Street.

Many of these buildings frame the streetscape with wings abutting the sidewalk. Often entryway and other courtyards are shaped and partially enclosed by portions of building masses. Some edifices sit back from the street and are surrounded by beautifully landscaped yards with mature deciduous and evergreen trees, plus dense shrubbery. Entrance porticos and drive-throughs frequently are provided, leaving little doubt as to the location of the front door and the civility of the residents who use it.

Many buildings are richly decorated. Stylistic aspirations range from neoclassicial to neogothic to art deco. The primary building material seems to be brick, but with a wide variety of color and textural manipulations. Carved and cast stone, plaster, ceramic tile, wrought iron and other decorative metals abound. The placement and variety of windows reinforce the visual presence of the facades of these giant residences.

Regardless of specific ornamental gestures, the overall effect of these buildings and their relation to the avenue is to convey a sense of elegance and affluence. But the pictures seem refined and composed, not ostentatious or pretentious. To speak of "upper Connecticut Avenue" is to conjure an image of both a lifestyle and a streetscape, of high-ceilinged apartments and a beautiful setting for walking and jogging.

Strolling along these residential stretches of Connecticut, one might wonder where the apartment occupants park their cars. Some buildings have parking in back, away from the avenue, and some have underground garages. Residents park along abutting streets, especially at night. And some apartment dwellers don't own or drive cars regularly. They are able to get around the city using buses, or the subway, one of the great conveniences of living along today's Connecticut Avenue.

What one doesn't see in front of these apartment buildings is vast parking lots. The avenue's width has not been visually tripled or quadrupled by lining it with more asphalt paving on which to drive and park automobiles.

Perhaps Connecticut Avenue and its traditions -- of land use, site planning and building design -- have something to teach us about making streets, something we have have forgotten on the Rockville and Columbia pikes.

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