Although Beijing and Washington are different in many ways, both world capitals struggle with transit, parking and housing woes. (Goddard_Photography/Getty Images)

What could Washington and Beijing possibly have in common? Surprisingly quite a lot, despite the huge differences between these two world capitals in history, culture, population, geographic area, natural environment and physical form.

Both capitals are plagued by severe transportation and automobile parking problems, exacerbated by public transit systems unable to adequately serve substantial portions of their metropolitan areas. And by the way, many cars in Beijing are not compacts.

Real estate prices are rising in both cities, although in China the state owns all land, which is leased for privately sponsored development and ownership of commercial and residential real estate projects.

Washington’s population is growing, but nothing like that of Beijing, which has experienced in-migration from the countryside that adds tens of thousands of new residents every year. As in the District, affordable housing for many middle-class and moderate-income residents is increasingly difficult to find.

Historic preservation of aging areas and buildings in Beijing is a politically controversial issue and entails the same kinds of competing interests as in Washington. Beijing’s government officials, real estate developers and private investors favor modern skyscrapers, total makeovers of old neighborhoods and enhanced economic growth.

But some historically sensitive citizens, urban planners and architects concerned with China’s cultural legacy feel that too many of Beijing’s traditional low-rise neighborhoods — especially aging “hutongs” — have disappeared, razed to make way for profit-making mega-projects.

Fortunately, some hutongs have been preserved, just as parts of Georgetown and Capitol Hill have been historically protected. Continuing to serve in part as habitation, a few hutongs have become picturesque destinations for Chinese as well as foreign tourists, their narrow streets and intimate passages lined by small shops, cafes and spaces for artists and artisans.

Today both capital cities are equally blessed with trees of all types lining streets and filling extensive public parks and gardens. Flowering spring vegetation now exists almost everywhere in Beijing, as in Washington.

However, Beijing’s greenness has been intensely cultivated and enhanced mostly during the past three decades, somewhat helping to improve the city’s ecology. Vegetation absorbs carbon dioxide and emits oxygen, but not nearly enough to solve Beijing’s frequent, sometimes debilitating air pollution problem.

Another significant contrast concerns planning policies and urban design characteristics. In Beijing, skyscraping verticality is the favored scale. In the District, horizontality rules.

Our basic street-block pattern, thanks to Pierre L’Enfant, is relatively fine-grained, enabling multiple travel-path options between origins and destinations. Beijing is handicapped by immense superblocks created by widely spaced east-west and north-south arterials, interlinked circumferentially by several beltway-like ring roads added over the years.

Vehicular traffic moving within and through Beijing cannot easily traverse the superblocks, where local streets are narrow and discontinuous. Consequently, the city’s reported 3 million cars are obliged to travel on the multilane arterials and ring roads, which typically are three times the width of K Street in downtown Washington. Yet these broad roadways are bumper-to-bumper parking lots most of the day.

In fact, vehicular mobility in Beijing is so bad that inhabitants are again riding bicycles and, more recently, battery-powered, noiseless motor scooters. As in Washington, many bicycles are shared, but without American-style bike stations. Tens of thousands of bikes are parked randomly throughout the city.

Using a cellphone GPS and app linked to a credit account, a user can scan a bike’s unique graphic code to unlock it, ride off to a new destination and then park the bike wherever there is space. Ending the ride and signing out relocks the bike.

One other urban design difference is evident. Despite Beijing’s many new, soaring, mixed-use commercial buildings, one sees little intention or consistency in how the public realm — streetscapes and plazas — is designed, framed and functionally animated by architecture. Fortunately, Chinese architects seem to be increasingly aware of this.

All of the above observations and comparisons came to light when I gave a lecture last month at Beijing’s Tsinghua University about the historical forces that shaped the American capital. I showed and explained how the L’Enfant plan, coupled with Washington’s evolving land-use and zoning regulations, guided — or constrained — our city’s urban development and architecture.

At the end of the lecture, the Tsinghua students — all of whom speak and understand English — surrounded me and said the same thing: Each plans to attend graduate school in the United States to see and study much of what I had just talked about.

Roger K. Lewis is a practicing architect, a professor emeritus of architecture at the University of Maryland and a regular guest commentator on “The Kojo Nnamdi Show” on WAMU (88.5 FM).