Expansion and Exclusion - Beijing as an art piece
Expansion and exclusion
By Neville Mars
Beijing as an art piece.
This is a story about Beijing, not about the myth of Beijing. This is about the real city, a city that grows along predictable patterns, illustrating typical Chinese development. . The myth of the modern Beijing is fed by projects such as the Olympic Village, the CBD and 798. The mere fact of their existence hopes to elevate the city to the global economy and cultural forum, their accomplishments spilling over to the rest of the city, improving the urban reality as time goes by. But 798 for one, as an incubator for art, critical culture and grass-roots innovations is no more. 798 is dead. The cause, one can argue, is authorities taking charge of its once self-organizing community. Perhaps it is just generic gentrification. DIAF, 798’s art festival has spread across the city and so it should be. If the myth of Beijing is to be realized, it’s time to look beyond the dozen dream projects at the city as a whole.
Slow progress
The city is man’s greatest invention. At ten thousand years old, the city is the framework of human civilization, the breeding ground of our trade and culture. Throughout history emerging cities have been planned, structured and designed, only to be restructured and redesigned as they developed. Ancient cities adapted to new technologies (sometimes with ease, often with force) to incorporate train tracks, air and seaports, logistic centers, tunnels, bridges, CBDs, entire transportation hubs, brain-parks and eco-belts. Our homes have been stacked into skyscrapers, our roads wound into clever knots of perfect curvature. Buildings have become flexible, facades inter-active, factories converted into museums, shopping internalized and historic centers preserved. As cities grow bigger and wealthier they continue to grow smarter, with more advanced technologies orchestrating their complex traffic flow, safeguarding against calamities, streamlining operations and managing over-all social and environmental well being.
Today the city has drawn 3 billion people within its urban realm. This is the ultimate proof of its intelligent planning and continued success. Or is it? If we were to design the perfect city, would it look anything like New York, Tokyo, Paris, Cairo, Sao Paolo or indeed modern Beijing? Would it suffer from severe congestion and pollution? Could it be made to serve the needs of all its citizens, instead of just a happy few? Would it big or small? Would it grow along with the economy, or would it be fixed, forever frozen in its perfect shape and size?
If only we could dream up what the perfect city should be, if only it was the actual product of our imagination: the designed city. Instead, we are caught in an eternal struggle to keep pace with the city’s self-creating urge to upgrade, expand, enlarge and encroach. Cities around the world suffer from shrinkage, but not (yet) in China. Here, we continue to escape the city only to be swallowed up again. Decades behind, China is catching up fast; unfolding in a fashion not too different from the American Dream that once was. The centers slowly grow more sophisticated and smart; the new-fangled peripheries stretch out in a mix of mind-numbing suburban typologies.
The Dynamic City
Urban design is only about keeping pace with reality. Indeed, at the Chinese speed of development, the practice of planning often equates to post-planning – retroactively justifying the emerged conditions, of which Beijing is a case in point. In 1958, after Beijing’s first decade of explosive growth under the Communist regime, extensive plans were drawn up to curb the city’s expansion and decentralize its growth. No less than forty new satellite cities were planned and population targets set. It wasn’t successful: the number of citizens kept swelling; the satellites never came to be. Steadily the proposed number of satellites dropped to 23, then 14, and then 11. Today three, those based upon pre-existing neighboring towns, remain investment-worthy. Over the same time period the population of Beijing more than quadrupled. This legacy, the production of proposals overridden by reality the very day they are presented, lives on. Beijing illustrates that in a market-driven context it is difficult to steer urban development in any planned direction. The sum of all the meticulously designed blocks and neighborhoods, roads and parks amount to just another big flaccid creature.
To design cities from scratch is even harder. Throughout the ages nations on the boom have attempted to define a formula for the perfect city; first in static plans, then with growth models along axis and vistas or fingers and strips. In contemporary China the favorite formulas include sub-centers, satellites and split cities. But the new city, from Brasilia to Marne La Valleé, has had a surprisingly bad track record. In reality, the success of the city, of the urban condition, comes with its ability to evolve; this is what makes the Metropolis intelligent. For better or for worse the modern city is a self-regulating, responsive system of supply and demand, all of its parts integrated in its equation. Take one block out, a bigger one will grow. Cut a road, diversions will occur. Invest in an area and rents will increase. But this wholeness doesn’t make the city designed – even if it were, this design wouldn’t be intelligent. Admittedly this is a bitter pill to take for a city and a nation bent on redesigning in entirety its cityscapes in a matter of two decades.
AnatomyWe observe the metropolis closer than ever. We probe her, monitor, chart and measure her progress. Slowly but surely we can define the city’s unique genetic constitution. Researchers – mainly outside the architectural field – are becoming better at predicting how the city will grow. This research provides designers with the tools to plan work within the anticipated urban form, rather than in opposition to it. But this in truth still doesn’t take into account the city as a whole organism. We analyze its anatomy, and then design alterations street-by-street, block-by-block, unable to imagine every detail, unable to control the outcome and effect upon the larger entity. Yet, undoubtedly, tackling problems such as congestion must encompass the complete system, all operations. Different elements of the city are interdependent: the size of the urban grid determines building typologies, which in turn effect urban density, further undermining public transportation accessibility, dispersion of work and living spaces, and so on. Furthermore, the chain is not definitely a linear one – any change will effect the development of the whole system. Change all the conditions or maybe just a few and the city is reengineered a new creature, a new Beijing. So, one must ask, at what point are alterations so profound that the city’s fundamental core is altered, its genetic chain recoded?
Modifying the metropolis
The buzz and debate of the 90s has settled. We have come to terms with the untamable city. Yet the question remains: how do we structurally improve the morphing urban landscape? To deal either with existing urban tissue or to expand the city’s footprint each requires different tools. If the metropolis has a mind of its own, one needs precise tools that can gradually redirect development and create insertions the city won’t reject. Equally, new cities and satellites are not static entities. Their ongoing growth should be anticipated, orchestrated by a framework from the start. (The Manhattan grid springs to mind. Projected on an agricultural island with blatant hubris, it has experienced a structured evolution from farmland to a dense cosmopolitan center.) However, this logic doesn’t seem to apply to Chinese cities. Their transformation is achieved either by superimposing big plans right on top of the existing city, or by the split city model: attaching an entirely new district to the side, leaving the old part to fend for itself. This is in contrast to the West, where dense regulations and a heavy consensus have minimized the impact of planning. In Beijing both of these planning models occur simultaneously at a large scale. With brute force Beijing’s anatomy is fundamentally transformed. Streets are widened; apartment blocks and office towers of entirely new proportions inserted. An immensely coarse fabric replaces the once incredibly fine fabric. All the urban elements are bigger, but are also spread farther apart. This has structurally transformed Beijing and as a result it operates differently. The coarseness makes the city hostile to the pedestrian. This is amplified by inner-city highways that cut downtown areas into isolated neighborhoods surrounded by giant walls of infrastructure.
The modern image of Beijing hinges on these mega-avenues aligned by mega-buildings and stepping stone projects. From the air Beijing reads like a belt of modernity that encircles a historic center (still being eroded), all embedded in a broad zone of dormitory blocks. (These living quarters define the majority of the cityscape and as such are arguably the essence of the ‘real’ Beijing. Yet this expanse of the capital seems to fall between the cracks of the planning debate.) Beyond the Fifth Ring Beijing extends in thick fingers of suburban high-rise and a puzzling amalgamation of villa-parks and village factories looming in clouds around them. Yet none of these realities seem to tarnish the myth of Beijing. Even though the target audience is very diverse, the city’s official image is projected with astonishing effectiveness, attracting foreigners as potential tourists/corporate investors, turning the Chinese middle-class into first time home-owners, and pacifying the migrant labor force with the persistent dream of progress and urban contentment in the horizon.
Stepping-stone planning, the insertion of mass-scale cornerstone projects, plays a central role in this strategy. In a context so pressured for fast development, it’s an obvious tool enabling government to take total control. But these big leaps pose a double threat. Architectural projects have swollen to the point they have taken over the scale of urban planning, its role all but negated. Residential compounds have privatized their public space and internalized their road systems – their walled-in streets converge to release cars through a single gate onto the highway. Moreover these star projects draw attention and planning in, away from any efforts to look at the city as a continuous spatial network. Increasingly the schism between icons and generic Beijing widens. The myth moves further away from reality.
Accessibility
The manifestation of Exploding Beijing.
Remarkably both the surge of infrastructure and the progressive fragmentation of the urban fabric are augmented by the same over-arching campaign to curb Beijing’s congestion. Since the 1980s, the expansion of the footprint of Beijing (and flattening of its density curve) from a once compact capital to what is commonly known as the Beijing pancake, has dramatically accelerated. The urban mass has effectively been redistributed over a vast plane and dispersed into small insular patches. In conjunction with the explosion of Beijing’s urban mass, its inhabitants are relocating to the periphery. They consist partly of middle- and upper class citizens following the exodus to the suburbs and partly of the floating migrant population. Without urban citizenship rights, this population is relocated by force from the crammed hutongs of “Lao Beijing” to cheap, inaccessible suburban compounds. Unlike the American suburb this delivers a diverse periphery of high contrast, not in an endless carpet of single homes, but rather clear blotches of walled settlements, be it rich or poor. They orbit around the core in a near perfect gradient of increasingly small patches. Trace these and the footprint of the city no longer resembles any of its maps. Shaped like a star stretching 80 kilometers in either direction, its circumference – the curving edges bordering the countryside – extends over 6000 kilometers.
The manifestation of Commuting Beijing
By 2020, a staggering extension of the infrastructural network should be in place. The transition to an open market has mobilized China’s work force. Beijing leapfrogs from one urban structure to a vastly different other: from the cellular urban structure, the “danwei,” or single-unit structure, characterized by impeccable spatial alignment between work and living quarters leaping to the suburban enclave, a cellular structure based upon complete separation and isolation. As a result, the numbers of daily commutes follow suit with the congestion of all transport systems. Any attempt to curb the city’s growth or to achieve a new alignment (aiming for some form of dispersion or independent settlements such as urban villages) is at odds with the intrinsic nature of the city: to facilitate connections! The city is the spatial network that accelerates people’s chances to interact, trade and collaborate.
To keep pace with the number of commutes in private cars, road surface is continually expanded. To simply maintain car density at current levels would require the daily construction of a three-lane, 10-kilometer stretch of road to serve the 1,500 new cars. Simultaneously a track-based mass-transit system will be established, larger than any subway light-rail network currently existing in the world. This will make Beijing a unique infrastructural hybrid of a vast network of broad roads and long tracks.
These two ambitious transformations, one centrally planned and one more accidental, are radically altering the constitution of Beijing. An infrastructural hybrid sounds good enough, but how can it answer to the increasingly coarse and fragmented urban texture of Exploding Beijing? How can we scrutinize its myth? How can one assess Beijing’s expanding periphery, when maps can’t be made fast enough? Or simply put: How should the modern metropolis be evaluated?
SymptomsIn the daily realities of Beijing life one acknowledges that most of the city is out of reach. From any position the city casts a pattern of blind spots – places too inaccessible to treat as regular destinations. Maybe you have a nice apartment on the east Fourth Ring; this makes it impossible to visit your friends in Fengtai district other than on the weekends. It is simply too far, too cumbersome. If you can afford a cab, you’ll have to be prepared to spend the morning in traffic. Public transportation is inexpensive but even slower and very uncomfortable. For all its complexity the efficiency of the metropolis can be reduced to its accessibility – the effectiveness of the connections it produces. In other words, the means, travel time and distance define urban accessibility for commuters and consumers.
Beijing’s congestion, though still in its infancy, is generally regarded as the city’s biggest problem, followed directly by air pollution. But if we consider the recent overhaul – the rigorous redesigning of Beijing – congestion can only be regarded as a symptom of the problem. We need to consider the root cause of congestion: the increasing inaccessibility of the city.
Beijing’s famous ring roads, numbered 2 to 6, already have a combined surface-area substantially larger than the entire historic heart of the city. To simply add more road surface will not reduce congestion, nor increase accessibility. Beijing’s road coverage does not equal the average of the West, neither does its car-ownership. The coarse inhospitable texture of Beijing means that for many citizens, the stations of the planned network will remain too inaccessible to be a comfortable alternative to the car. Yet, in fact, Beijing traffic researchers estimate the bus will still remain the principal mode of transport. For decades to come, as much as 80% of public transportation journeys will be made by bus. This statistic is likely to be accurate, as more and more residential compounds are built far beyond the light rail network’s reach and as large numbers of unofficial citizens increase in the periphery’s temporary settlements.
Insertion and contraction
The title of this article, “Expansion and Exclusion” suggests a direct link between the spreading of Beijing’s footprint and social segregation. Opportunities are not equally distributed and are often out of reach. Spatial disconnections and gaps are contributing to the disparity of wealth. Car communities are fenced off, neighborhoods monotonous, and street life disappearing. Beijing’s arteries are designed solely for technocratic and political objectives – to streamline the throbbing traffic and for prestige and war. This is not public space. Official public space is formalized, equally fenced off and controlled, in mega-parks. Opportunities for chance encounters, the type of social interaction at the core of urban existence, need a certain trait of friction, a certain smallness, and thus are steadily lost. The vast amount of residual space, the nooks and crannies of mega-infrastructure is what remains for Beijing’s bottom strata to wander and sift through.
Can we put Beijing back together again? With the inner-city highways in place, a solution for the rebirth of a pedestrian-friendly city– to patch the city back together – is almost unthinkable, an impossibility. However observant of future growth patterns designs might be, a split city approach of new developments in the suburbs will openly aggravate the commuting times of the entire city. And so, infrastructure is the remaining tool to reengineer the metropolis. I propose a precise insertion, using only the surface above Beijing’s ring roads. But yes, it needs to be BIG. If this comes as a surprise, some nuance is in order. However unreliable, Big thinking surely is not lacking in China, nor is long-term planning. But for the most part China’s fondness for bigness amounts to crude architecture and brutal infrastructure. Our plea is for smaller building projects that give detail, diversity, and definition to the urban space and interact with the public domain.
We have developed a hybrid transit system that accelerates pedestrians to the speed of a train. The D-rail combines travelators (flat escalators) with Maglev (magnetic levitation train) technology. The D-rail runs as a single continuous carriage around the city, its head connecting to its tail. There are no stations, it never stops, and you never have to wait. Commuters can get on board at any point on the loop. This pedestrian fast-lane hovers in a glass tube over Beijing’s Ring Roads; a small one on the Third Ring and a larger stacked D-rail on top of the Fourth Ring Road, comprising retail, a rooftop park and arms stretching out to surrounding cityscape. The D-rail makes the highway space the pedestrian zone, re-linking neighborhoods, utilizing the urban no-man’s land. It is a big attempt to bridge Beijing’s gaps, a giant gesture to connect, diversify and dramatically shrink the urban network.
The role of the D-rail is to absorb the millions of citizens living outside of the Fourth Ring commuting to and through the center every day. Public buses, the real mass-movers of today and tomorrow are already congesting the streets of downtown Beijing as they amass from the larger region within the center. The D-rail halts regional buses on the Fourth Ring to offer immediate transportation to any point along the ring and further with dedicated transportation to the city center. Every three minutes the D-rail decelerates, the doors open all along its 64 kilometers-long magnetic track. People transfer to local travel belts moving at the same speed, choosing escalators up to the rooftop park or down into the retail decks. Beijing’s massive Fourth Ring Road becomes a prime destination.
The hub is the heart
Infrastructure is the way to modify the modern metropolis, but how can one accommodate the 5 to 10 million additional residents expected in the capital over the next two decades? If any urban extension further aggravates transport, can we contain Beijing, and curb its brutal urge to grow?
In absolute terms there is no need for Beijing to expand more then 30 meters outwards for its 2020 population to live comfortably. This minor expansion along its 6000-kilometer perimeter of bits and pieces would provide sufficient new living space. However we can assume a city has its own tendencies, and in Beijing these are exacerbated by policies and bogus, speculative investments. The total surface of development zones expected by 2030 will fill the entire rural plane between Beijing and Tianjin.
The only natural way to curb Beijing’s expansion is by stimulating its growth according to its anticipated round footprint – not outwards, but by coaxing growth inwards along the backbone of mass transportation, along the D-rail. Within the Third, Fourth and Fifth Ring Roads densities should not decrease but increase. People should not be moved out of the historic center, but rather the commuter-dependent office buildings relocated, beginning with Beijing’s four hundred car-swamped government buildings and institutes. Moving urban function out of the center is the most effective way to curb peak congestion. Their new location: the Fourth Ring Road. Their new mode of transport: the D-rail.
Planning the relocation of the administrative center is not new. In fact, it has a history not unlike Beijing’s satellites. Only, when Liang Sicheng presented his plans for a new city center, in an attempt to create modern space without disrupting the fine hutong fabric, he was blacklisted.
The time may finally be ripe. The Fourth Ring is already a booming belt of modern apartment compounds, Zhoungguancun and the CBD. The D-rail would be the catalyst to connect all of these scattered points, a transport hub and retail loop supported by millions of daily commuters. With a linear park on its roof decks it’s positioned right where Beijing’s first green belt was once intended. The relocated government offices, museums, schools and institutes complete the network of connection, the critical mass needed to make a truly diverse new center of the capital.
Imagine walking through the Circle Center with the option to travel anywhere else in the city almost instantly. Unrestricted, uninhibited, you wander from shops to bars, through the lobby of a hotel, past the offices of a bank or business, always comfortably inside and always free. This is the experience of a public pedestrian network connecting the buildings to an efficient pedestrian realm. Yet, this is nothing new for China; Hong Kong has a beautiful pedestrian passage in place. But the Circle Center with the D-rail at its core could be something of a different order and appropriate to Beijing’s impressive reality. It will revive Beijing with a double by-pass and a new lung in order to grow a vibrant new heart!
扩张与排斥
何新城
北京是件艺术品
这里讲述的是关于北京的故事,一个鲜活的城市,一个真实的故事,而非虚构的神话。北京沿袭了中国式城市发展的传统,而它彷徨在激烈的融合与对抗中却生机勃勃、活力四射则是个奇迹。奥运村、CBD和798的涌现让它更为传奇。它们不但成功提升了城市的形象,而且让北京成为全球经济文化论坛的平台;随时间的流逝,它们的影响力更将发扬光大。大山子艺术节已经美誉全城;然而曾为艺术、批判文化和草根创新的孵化器的798,已经死去。究其原因,或许是权力部门接管了这个自组织的社区,或许,798的死不过是财富流动、适者生存的自然结果。要探索北京发展之谜,我们有必要超越诸多形象工程、打破传统视角来仔细审视北京作为一个城市的发展进程。
城市路漫漫
城市是人类文明最伟大的创举。经过一万年,历经兴衰的城市俨然成为人类文明的框架,是文化与商业的温床。历史上的城市被规划、改造、再规划、再改造…… 城市总有它存在与发展的理由。今天,新技术的应用、新概念的引入让承载着不同历史的城市千姿百态。轨道交通、空港河港、后勤中心、隧道、高架桥、中心商务区、交通节点、科技园以及生态保护带等等带来了传统城市的新生(有时轻而易举、有时武力相加)。我们的家叠加而成了摩天大楼,道路扭结成完美的螺旋,工厂变成博物馆,建筑富于弹性,立面变得互动,购物活动室内化,历史街区被保护……随着城市空间的拓展和财富的增长,它们也越来越聪明,高科技被应用于复杂的交通指挥与灾害预防,关照社会与环境的福祉。
今天的城市是全球30亿人口的庇护所——这似乎是聪明的规划已经成功的最好明证。然而果真如此吗?假如让我们来设计一座完美的城市,它是该像纽约、东京、巴黎、开罗、圣保罗,还是像现代的北京呢?它会遭受严重的拥堵和污染吗?能否应所有公民的需要而建设城市,而不仅是生活殷实的一小撮呢?它应该随经济增长同步扩大,还是凝固下来、保持完美的形态和规模呢?
如果能梦见最理想的城市是什么就好了,如果能摸索出一步到位的完美城市发展模式就好了。在现实中,我们却无法逃脱规划总是落后于城市升级、扩张、增长以及蚕食的挣扎。当世界上大部分城市都由膨胀转为萎缩时,中国的城市化却截然相反。在这里,都市中人一次次试图逃离城市的喧嚣,却不断被汹涌的城市扩张浪潮所淹没。中国的城市化进程虽然落后于西方数十载,其追赶速度却相当惊人,与当初的“美国梦”很有一拼。中国的城市中心日益智能化,城市边缘的蔓延非常多样化,呈现出一派混杂的郊区发展势头。
动态城市
城市设计需要与时俱进,而中国的发展速度让所有的规划与设计都立刻过时。共产党当政10年后的1958年,北京市第一个总体规划出台了,目的在于遏制十年来经济飞速发展带来的城市膨胀,缓解城市资源和人口的压力。当时的解决方案是规划了40多个卫星城,并试图限制北京的城市人口。结果却不成功,尽管设限,城市人口却持续增长,卫星城的繁荣也从未实现。在此后的历次规划中,卫星城的数量则逐次减少,从23到14、11,而今天只有3个在旧县城基础上规划的卫星城对人口与投资还有些吸引力。与此同时,北京市的人口仍然有增无减,目前的数量比五十年前翻了四倍多。而日新月异的现实让城市规划的提案在出生之日即被现实抛弃。北京证明:在市场经济的框架下,用规划引导城市的发展方向其实相当困难。精心设计的街区、邻里、道路、公园等所谓理想组合不过是大而不当的简单堆砌。
从零规划新城则更为困难。纵观历史,诸多增长爆炸期的国家都在寻找完美的城市发展模式。从早期的静态规划,到后来的点轴增长模型都是尝试的结果。在当代中国,“副中心”、“卫星城”、“新城”等都是相当有人气的模式,尽管诸如巴西利亚、马思和谷等新城规划却无不是失败的案例。究其原因,在现实中,城市的成功发展,城市环境的改善与城市的自我发展能力是息息相关的。这一自我发展能力正是让大都市聪明起来的源泉。也就是说,现代城市是个庞大的自我管理、供需互动的有机体,所有部分都按比例地整合在一起。如果我们铲除一个街区,一个更大的街区会出现;切断一条道路,替代的道路将出现;在某块土地上投资,当地的房租会上涨。作为有机体,城市是不可以被规划或设计的;即便可以,这样的规划或设计也不会是聪明的。对于一个打算在二十年内重新规划全部城市空间的国家来说,这一论断无疑是一剂苦药。
解剖城市
我们史无前例地近距离观察城市,探索、观察、测量并图表化它的一举一动。渐渐地,我们可以很有把握地确定城市独特的基因组成。建筑学范畴外的学者可以日益准确地预测城市未来的发展趋势。对于城市规划者而言,这些研究结果无疑是构思理性城市的辅助工具。但从根本上,他们仍然没有把城市当作一个有机体来对待。我们可以对城市进行功能分区,然后逐条街道,逐个街区地进行设计。但是这样仍然很难兼顾细节并准确预测结果。即便是解决城市交通拥堵的问题,也不可能脱离城市整个系统的运行来单独考虑。城市的各部分是紧密相连的。比如城市网格的大小与居住形式是紧密联系的,它们还会影响到城市的居住密度、交通的可达性以及居住与工作空间的分布等等。更重要的是,城市这种组分与组分之间的相关性并不是简单的线性关联,任何一个小小的动作都会牵一发而动全身,局部乃至整体的改变都意味着城市的重生。对于北京,我们则不禁要问,城市的变更究竟要深到什么程度才算城市的基因链发生了突变呢?
都市大改造
上世纪90年代关于城市的争论已告一段落,我们所面临的仍然是不可驯服的城市。尽管怎样驾驭这变幻莫测的城市仍无定论,但我们已经看到:无论是改造现有城市还是在城市的边界外开发新城都需要一些技术手段才能解决。如果大城市有自己的思想,那么处理这些问题的工具至少不该违背城市的意志,还应该对城市的发展有逐步的引导作用。新城也好,卫星城也好,它们作为城市改造的工具并不是一成不变的。它们的发展变化应该在一开始时就加以预测(例如曼哈顿从一片农田发展成为国际大都市)。
然而这种逻辑对于中国的城市并不适用,西方城市规划高度依赖人口普查和人口密度控制,并试图将规划对城市的影响降到最低点。与此截然相反的是,中国的城市转变是在强制规划的框架下发生的。这些强制规划往往不是脱离实际的宏观规划就是在旧城旁建设新城。例如,北京就同时存在着旧城重改造与新城开发这两种强制规划的模式。它们的并存则粗鲁地肢解了北京城——街道被拓宽,公寓和写字楼生硬地被嵌入,野蛮拼凑的城市结构取代了传统的秩序与优雅。城市的所有成分都在往“大”里发展,包括边界。这些不仅改变了北京的城市肌理,也让城市的功能明显异化:穿越马路的行人不能不望“街”兴叹。而城内的马路则把市中心分割成孤岛似的社区,个个被基础设施的巨墙所包围,真是雪上加霜。
现代的北京已经成了巨型街道、大型建筑以及形象工程的代名词。从空中俯瞰,北京是将历史文化中心层层包裹的现代化聚居环状带,中间是宽大的方格状居住小区(这种居住形式是北京城市形态的主要内容,也就是被称为“老北京”的象征,但在规划中,这种形式仍然极富争议)。五环之外,北京像张开的手指一样向外蔓延,郊区的高层住宅、别墅群、冒着黑烟的工厂参差错落,但这些并没有玷污北京的传奇色彩。尽管目标观众千差万别,北京的官方形象却带来了惊人的效率——比如吸引投资人/游客,让中产阶级开先河地成为私房拥有者,用发展和城市化的美好前景来安抚农民工等都有奇效。
里程碑式的规划、大规模标志性工程的嵌入往往是政府提高形象策略的核心招数。在亟需快速发展的巨大压力下,该策略的确让政府一切尽在掌握。然而,这一大跃进却存在着双重隐患。这些建筑单体往往挤占了城市规划的地位,规划的作用被完全忽略了。居住小区让公共空间私有化,道路系统被小区的围墙生生切断,只有一两个通往公路的出口。更严重的是,这些明星工程转移了人们应该将城市看成连续空间网络的视线,形象工程与北京的现实极不同步,而北京的传奇也与现实渐行渐远。
有关可达性
北京大爆炸
值得关注的是,在试图解决交通拥堵的北京“建桥运动”同时,基础设施的剧增与城市的破碎亦步亦趋。自上世纪80年代以来,紧凑的城市结构开始膨胀,并一发不可收拾地变形成了今天的“大饼”。城市中的一切在更为广阔的空间中进行重组和分配,分散成了片状的、相互隔离的“岛屿”。随着城市的爆炸性蔓延,居民却逐渐向城市边缘聚集。他们中既有主动追随郊区化大潮的中产及高产阶级,也有被动搬迁的流动人口——他们没有城市居民享有的权利,这一群体被迫从“老北京”的胡同迁至廉价的郊区。与美国的郊区化不同的是,这里不是连片的私家住宅,而是一个个无论贫富,都由显眼的高墙围合的居住群体。它们向一个个小的经济“中心”靠拢,它们的轨迹以及城市的边界也变得捉摸不定。成星状散射发展的北京在各个方向的蔓延已到达距市中心80公里的地方,而这个散射的城市边界(包括郊区)已经超过了6000公里。
北京的通勤大军
到2020年,基础设施的扩张将有所缓解,向市场经济的转型激活了中国的劳动力市场。北京的城市结构也呈“蛙跳”式发展:原有的蜂窝式城市结构——“单位”,其工作与居住密不可分的城市格局迅速向郊区化、彻底分离的蜂窝式城市结构转变。于是日常通勤人流制造了该时段各种交通工具的严重拥堵。任何试图遏制交通拥堵和分散城市人口的举措都与制定这些举措的初衷——“加强联系!”自相矛盾。而城市的初衷又是什么?城市本该是加快交流、聚拢交易与合作的空间网络!
相对于日益增长的驾驶私车的通勤人士,道路必须相应地持续增加。按照现有的私车增长速度(每天1500辆),北京市应该每天增加10公里长的三车道公路。与此同时,轨道交通也应突飞猛进,让北京的交通变成由巨型公路网络与长里程轨道交通相结合的混合体。
公路和轨道交通的宏伟改造计划同时在进行,一个由中央政府规划,另一个则相对灵活,它们会让北京翻天覆地。但这些变化能解决日益严重的粗糙化与“北京大爆炸”日益碎片化的问题么?这其中的原因何在呢?如何在如此快速的增长之下去勾勒北京的城市边缘呢?简言之,我们该怎样去评价现代的大都市呢?
症状
在北京的日常生活中,城市的大部分地区是居民日常生活的盲点,很难够得着。如果你在东四环有一个公寓,那将意味着除非在周末或休假期间,你无法拜访住在丰台区的朋友。如果你打得起出租车,那么你得准备一早上都在车里度过。当然,公交车很便宜,但是慢得像乌龟而且极不舒适。无论交通系统多么复杂,衡量其效率的指标都可以简化为交通系统的可达性,即交通连接出发地与目的地之间的效率。城市系统的可达性,概括的说,取决于通勤时间的长短和通勤线路的长度。
虽然还处于婴儿期,交通拥堵问题却已是北京最严重的城市问题了,紧随其后的是空气污染。但如果我们审视北京最新的变化以及那些貌似很有激情的设计,我们就会看到,北京的堵不过是众多城市问题的症状之一而已。我们有必要探究交通拥堵的根本原因:这个城市与日俱增的不可到达性。
北京著名的环路,从二环到六环的总占地面积比紫禁城还大。简单地增加道路面积并不能缓解交通拥堵或增加可达性。北京的道路覆盖率并不及西方的平均水平,私家车的人均拥有量也不及。然而北京粗放式的城市结构意味着交通网络的节点极不可达,相对于舒适的私人汽车来说全无可比性。然而学者预测,公共汽车仍将是未来的主要交通方式。在数十年内, 80%的出行仍将依赖公共汽车。这一预测相当可信,因为越来越多的居住区在轨道交通还未到达的地方拔地而起,而大量的流动人口也将聚集在城市的边缘地带。