Every village, town and city should have at least one special, ceremonial street. Many don't.

Like so many other urban phenomena, the concept of the ceremonial street is ancient. Roman towns and cities routinely dedicated certain streets to ritual procession, public celebration and ceremony. Along such streets and at their end points were temples, government buildings, arenas and squares befitting and reenforcing the nature of the street itself.

Later, Renaissance and baroque planners of cities in Italy, France, Spain and Northern Europe created secularly inspired grand boulevards leading to monuments, triumphal gates, plazas or seats of government, as well as to cathedrals.

Older cultures in Indo-China, China and Japan likewise created special streets and sacred precincts intended for collective ceremony and ritualized procession.

European and Asian designers usually relied on grand compositional strategies for laying out such streets and spaces. Legible plan geometries, often based on circles and squares, and spatial relationships, often axial, would connote intuitively the uniqueness of these ceremonial routes.

But a different tradition took root in America. Powerful, uncoordinated mercantile forces shaped most cities and towns once a grid pattern was chosen. The character of streets was influenced primarily by transportation efficiency and convenience, land speculation and zoning predicated on segregation of land uses. Local jurisdictions were reluctant to impose grand master plans on a free and independent real estate market, especially in light of changing political interests.

Thus, few American cities have ceremonial avenues like Paris' Champs Elysees, Berlin's Unter den Linden or Washington's Pennsylvania Avenue. Such avenues have to be invented, designed, cultivated and maintained. They do not occur by accident. They are not an inevitable byproduct of laissez-faire capitalism.

What specifically makes a street grand and ceremonial? And does it matter if cities such as Houston, Baltimore, Newark, Los Angeles or Phoenix don't really have such streets?

Washington's Pennsylvania Avenue, as originally envisioned by L'Enfant, connected the president's house with the houses of Congress. The connection was to be symbolic as well as functional and experiential. L'Enfant sensed a need for something significant -- a monument, an important public building or plaza -- at the ends of such streets.

Pennsylvania Avenue between the White House and Capitol is straight, and few world-class ceremonial streets curve. This is because people moving along straight streets can see the street space fully in extended perspective, with their eye led axially toward real and meaningful visual destinations. When streets curve or bend, vistas shorten and destinations disappear.

Another characteristic of ceremonial streets, typified by a revitalized Pennsylvania Avenue, is an appropriately generous and well-proportioned cross section. Street widths must be sufficient to allow long perspective views up or down the street's length. Further, sidewalks and roadways must be ample enough to accommodate large numbers of people in the course of promenading, celebrating or demonstrating.

The ceremonial, processional image of such streets can be enhanced by lining them with regionally appropriate trees and with lighting standards of appropriate scale and style. Benches and kiosks should be part of the procession. Walkway surfaces may be paved with special materials -- granite, slate, marble or brick -- and not concrete or asphalt.

Elegantly designed esplanades can occupy the centers of such roads, providing additional space for streetscape vegetation. Esplanades may also increase safety not only by separating traffic, but also by offering pedestrians crossing the road a relatively safe, temporary haven at midstream. Visually, esplanades add another set of parallel lines to the perspective framework and axial vista within the streetscape.

Ceremonial streets should be lined with buildings whose height and mass are appropriate to the street's width. If buildings are too low or too far apart, the street space will lack containment and "leak" out visually. On the other hand, if buildings are too tall, visible sky areas may be excessively diminished, leaving the street space shady and somber much of the time.

Pennsylvania Avenue's cross section seems to manifest reasonable ratios between height and width -- the latter is somewhat less than twice the former. If the buildings were twice as high or the Avenue half as wide, the street space would probably seem too constricted. Conversely, if the buildings were half as high or the Avenue twice as wide, the street's proportions would seem suburban.

The evolving grandeur of Pennsylvania Avenue would not have been achieved without public design and development intervention. Near the end of the 19th century, there was little that was grand about Pennsylvania Avenue. Its character and the structures flanking it had been built mostly through unfettered, independent commercial entrepreneurship.

In this century, fortunately, the federal and city governments decided that, for purposes of historical intent and good urban design, Pennsylvania Avenue should be the capital's and the nation's primary ceremonial street. Its form would be mandated, its architecture carefully controlled.

Today, though still unfinished, Pennsylvania Avenue is lined by commercial and governmental buildings. There are vast federal agencies in neoclassical edifices, elegant new and old hotels, shops and shopping arcades, restaurants, speculative office buildings, Washington's city hall, a theater, museums and soon, Canada's chancery. There will even be some housing for those who can afford it.

Pennsylvania Avenue's buildings have had to respect and abide by legally adopted comprehensive plans. Architectural design must conform to special standards regulating setbacks, bulk, height and aesthetic quality (judgment calls by enlightened commissions). And some buildings aspire to elevating commonplace, daily activities -- shopping, walking, eating, working -- to the level of ceremony, adding to the avenue's overall sense of being a ceremonial place.

Added to all of this are periodic open spaces and plazas straddling or adjacent to the street. Such spaces augment ceremonial and celebrational opportunities by interrupting (hopefully without destroying) the linear, facade-flanked perspectives up and down the avenue. They, too, contribute both daily and occasional special rituals to the collective rituals of the street as a whole.

Pennsylvania Avenue is the site of one of the nation's and the city's most significant ceremonial events, the presidential inaugural parade every four years. It also is used regularly for countless other parades, marches and demonstrations whose purposes you may or may not agree with.

No matter what causes you support or for whom you cast your presidential vote, you must admit that it's nice to have a majestic, ceremonial street that can accommodate everybody. Indeed, no city should be without one.

NEXT: Embassy Row.