PEDESTRIANIZATION as another approach to urban renewal is now being seen in the "walks" and "streetscapes" of Roxas Boulevard, Eastwood, Makati, Morato, and Avenida Rizal. This trend began in the West in the 1960s and was picked up decades later by Singapore, Kuala Lumpur, Beijing and Shanghai. Now it is allowing Metro Manilans, having been without real sidewalks for over half a century, to rediscover the joys of walking. But wider availment of this pleasure isn't possible because of street vending and the usurpation of sidewalks for myriad other uses like parking, barangay halls, religious grottos, and even karaoke parlors. The problem then is not the lack of sidewalks but a lack of space for all these other functions the city needs-more markets, parking structures, community centers, leisure facilities-and yes, even public toilets.

	Avenida Rizal used to smell of piss, but it has become a pedestrian paradise.

Avenida Rizal is on the right path. It used to smell of piss and harbor hundreds of kariton people. Today, it has become a pedestrian paradise. The old movie facades have been cleaned, heritage buildings spruced up, and stores are doing brisker business.

But downtown Manila needs a lot more than just a street makeover. The University Belt, which occupies much of downtown and its periphery, present a peculiar situation: 300,000 students in over 60 tertiary institutions within shouting distance of each other. This part of Manila is a city unto itself. The U-Belt has engendered a single-use district with a monoculture of college students. Many live in rat-hole dorms regulated only marginally by the city. Almost all establishments cater to this single demographic, leading to a proliferation of fast-food joints, cell-phone shops, Internet cafes, and instant-thesis centers. Students spend years in this district with little interaction with the world outside and come out ill-equipped to relate to the larger community.

In a more balanced country or large region, tertiary institutions are located as part of a hierarchy of educational institutions from primary to secondary to adult-education community colleges. This also ensures that cities can accommodate these institutions within planned infrastructure to prevent traffic buildup and the dense clustering of services to cater to a single type of customer.

Our cycle of clustering educational facilities began with Intramuros. Before the Second World War, the walled city was filling up with too many schools, such that some, like the Ateneo, moved out. After the war, schools moved even farther, to Diliman, Caloocan, and San Juan following the several waves of residential flight from the central city.

Successive rings of housing development called "subdivisions" have radiated from the Manila since the early 20th century. Before the war, it was to immediate suburbs like San Juan, Pasay, Kaloocan, and the Mandaluyong estate. In the 1950s, the second wave expanded to Quezon City and Makati in gated "villages" like Forbes and Philamlife Homes and public housing "Projects" numbered one to seven. In the 1960s, subdivisions popped up along Highway 54 (today's EDSA) in places like Greenhills, White Plains, and Blue Ridge. The 1970s pushed the boundaries outwards to Parañaque, Las Piñas, Alabang, the Antipolo hills, and Novaliches. In the last 20 years urban sprawl has extended to what is termed "exurbia." Green fields in Bulacan, Pampanga, Rizal, Quezon, Cavite, Laguna, and Batangas are turned into gated communities, housing a huge chunk of the NCR population of about 15 million.

	Manila in the prewar period had broad, tree-lined avenues and a well-defined center.

THIS URBAN sprawl, now the definitive physical characteristic of the metropolis and the NCR, is sustained by dependence on car-based transportation. Only now has the central core and the fourth ring road (EDSA) been linked by rail-based mass transport. In other countries, mass transit parallels road development and transport planning dovetails with larger comprehensive land-use planning. Here, the infrastructure to support the sprawl has always lagged behind. Unscrupulous developers sell house-and-lot packages in remote subdivisions with only a country road connecting pseudo-Mediterranean housing to already clogged highways. This sprawl is an unstoppable virus fed by the need for millions of housing units. Yet supply will never be sufficient because population increase cannot be reined in.

To put it in perspective, the Philippines has to build five times as much housing as the Singapore government has in the last 25 years — tomorrow, just to catch up with demand. It doesn't help that low-density, single-detached housing is the mantra of a market raised to understand property as only that which stands on solid earth.

Urban sprawl has generated alternative physical constructs in satellite central business districts or CBDs and mixed-use complexes. The homogeneous horizontal sprawl outward from EDSA is now punctuated with islands of towers and big-box malls. Makati was the original alternative CBD to Binondo. Now clones have spread along EDSA, in Rockwell, Ortigas, Cubao, Eastwood, and out in Alabang. These are what Joel Garreau calls "edge cities," pocket urban developments that spontaneously appear wherever low land prices, highway access, and proximity of a large residential population exist.

This ad-hoc development further upsets the original circumferential and radial systems of roads and highways. Trips are not generated in simple house-to-work scenarios, in and out of central cores. Transport vectors point everywhere, making franchise allocation and road carrying capacities a nightmare to project. Road widening will not alleviate the problem: the Braess paradox states that no matter how much road you build, it will always get filled up. Unless we make a radical switch to rail systems (which operate under capacity because of jeepney and bus lobbies), traffic will always be a mess.

Ultimately, it's a question of size. How big can Metro Manila get? Already it is so huge and homogeneous that the silliness of keeping governance separate in 17 jurisdictions is obvious to all but politicians. The sense of place and community for people nowadays is not determined by abstract political boundaries. These are rarely in synch with physical boundaries of thousands of settlements, gated villages and subdivisions, all with their own associations, de facto governments that take care of basic services the real authorities cannot deliver.