作為公共空間的交通樞紐

張利/ZHANG Li

當(dāng)代生活的一個(gè)重要部分是移動(dòng)性。以任何現(xiàn)在的都市居民而言，日常生活的時(shí)間有很大比例是在公共交通空間里度過的。哪種形式的公共交通是最好的公共交通？對(duì)此每個(gè)都會(huì)有不同的答案。不過21世紀(jì)的城市設(shè)計(jì)家們似乎在這個(gè)問題達(dá)成了一定程度的共識(shí)：由軌道（重軌或輕軌）連接的超級(jí)密度組團(tuán)是最值得提倡，也是最具可持續(xù)性的[1]。類似的，在當(dāng)今的城市更新項(xiàng)目中，不管是在發(fā)達(dá)國(guó)家的城市還是發(fā)展中國(guó)家的新興城市，與軌道交通相關(guān)的基礎(chǔ)設(shè)施更新也是頗受關(guān)注的熱點(diǎn)。我們經(jīng)常體會(huì)到的現(xiàn)象是，無論對(duì)于城市的居民還是對(duì)于城市的造訪者來說，軌道交通空間已經(jīng)成為了事實(shí)上的城市識(shí)別性的締造者之一。軌道交通（換乘）樞紐中的聲音、氣味、觸感與背景氛圍共同交織成了一種難以忘懷的經(jīng)歷，以不可忽視的方式參與了我們生活品質(zhì)的定義。

軌道交通（換乘）樞紐是城市化的產(chǎn)物，其出現(xiàn)可追溯到工業(yè)化的初期。然而就像現(xiàn)代城市本身經(jīng)歷了很長(zhǎng)的歷程才認(rèn)識(shí)要把人放回到一切考慮的中心一樣，交通樞紐在接受自己是普通人的城市公共空間這一角色定位之前，也經(jīng)歷了漫長(zhǎng)的技術(shù)至上與形像崇拜過程。過剩的石頭與鑄鐵的紀(jì)念性曾一度是帝國(guó)式的經(jīng)濟(jì)進(jìn)步的標(biāo)志。超尺度的屋蓋與巨型的內(nèi)部空間讓交通樞紐更像是宮殿而不是站房。令人頗感意外的是，這一源自歐洲帝國(guó)主義時(shí)代的交通建筑紀(jì)念性傳統(tǒng)在歷史上竟獲得了比產(chǎn)生它的那些帝國(guó)更長(zhǎng)的生命力。從傳統(tǒng)的城市到新興的城市，對(duì)交通樞紐紀(jì)念性形像的追求似乎令人欲罷不能。在20世紀(jì)的莫斯科我們看到宮殿式、博物館式的地鐵站的繁盛。在21世紀(jì)我國(guó)的新城我們看到高鐵站構(gòu)筑的宏偉。在最近的紐約，我們?cè)俅我姷搅艘钥鋸埖募夹g(shù)表現(xiàn)樞紐形像的高顯現(xiàn)度案例——只不過其實(shí)現(xiàn)的材料是透明玻璃和白色金屬，而不是石頭與鑄鐵罷了。

具有諷刺意味的是，作為公共空間的交通樞紐出現(xiàn)于一個(gè)與之并不相容的政治氣候中。20世紀(jì)第二個(gè)10年，以在西方各國(guó)影響加劇的經(jīng)濟(jì)危機(jī)為背景，莫索里尼政權(quán)的主要政策定型并開始主導(dǎo)主要意大利城市的進(jìn)程。在隨后的一段時(shí)間中，作為刺激經(jīng)濟(jì)的主要手段，各大城市紛紛在中心區(qū)域進(jìn)行以公有資金支持的大型交通基礎(chǔ)設(shè)施建設(shè)。1933年佛羅倫薩的主火車站競(jìng)賽把以米凱盧奇為首的年輕建筑師團(tuán)隊(duì)推向了前臺(tái)，他們?cè)O(shè)計(jì)方案所承載的“對(duì)新建筑的宣揚(yáng)直接引發(fā)了一場(chǎng)在（政治允許的）界限內(nèi)的爭(zhēng)論，而這一爭(zhēng)論針對(duì)的是（對(duì)公共交通空間屬性的）立場(chǎng)與獨(dú)特解決方法”[2]。這一“爭(zhēng)論”的焦點(diǎn)或“獨(dú)特解決方法”所指的正是與城市標(biāo)高取平的大通廊空間（不再被有意架高）集成大量的日常城市服務(wù)功能。當(dāng)然，佛羅倫薩主火車站當(dāng)年的城市性空間與今天的同類空間在尺度上與豐富程度上都不可同日而語，但它確實(shí)是一個(gè)典型的早期案例，不僅對(duì)火車站、也對(duì)所有城市公共交通樞紐給予了一種新的定義，在這種定義下，強(qiáng)功能性的車站與泛功能性的城市公共空間之間的界限開始被跨越。

80余年以后的今天，我們幾乎可以安心地說，交通樞紐已越來越多地被默認(rèn)是城市公共空間的重要類型。雖然反例還是屢見不鮮，但絕大多數(shù)的交通樞紐對(duì)待人性化體驗(yàn)的態(tài)度是嚴(yán)肅的。我們可以通過4個(gè)特性來識(shí)別這一交通樞紐向人性化公共空間轉(zhuǎn)型的進(jìn)程。

第一個(gè)特性是給予慢行交通以空間主導(dǎo)權(quán)，設(shè)計(jì)大面積的連續(xù)延展表面以供行人與自行車使用。多數(shù)現(xiàn)代交通樞紐或換乘中心會(huì)有意弱化傳統(tǒng)車站的通廊與候車室構(gòu)架，而用室內(nèi)的公共廣場(chǎng)和街道來對(duì)其進(jìn)行替代。無論在新建交通樞紐還是老舊車站的改造中，這一屬性都有著相當(dāng)明顯的表達(dá)。蘇黎世中心車站的改造索性把老站房的內(nèi)部全部清空，形成一個(gè)完整的室內(nèi)公共空間，類似一個(gè)傳統(tǒng)的城市中心市場(chǎng)。這種類型學(xué)的功能柔性與空間活力可謂是任何21世紀(jì)國(guó)際都市的主要加分項(xiàng)目之一。

第二個(gè)特性是在交通樞紐空間內(nèi)集成豐富的休閑與公共服務(wù)功能。不僅是零售、咖啡、餐廳等傳統(tǒng)的交通輔助功能，還包括畫廊、游戲廳、展覽廳甚至電影廳和圖書館等文化休閑功能。這在近期新一輪的歐洲城市火車站建設(shè)中非常普遍。代爾夫特新的中心火車站顯然沒有忘記其城市的塑造者——代爾夫特技術(shù)大學(xué)的存在，因而在火車站的水平向大廳中設(shè)置了多個(gè)新能源技術(shù)汽車的展臺(tái)，把大廳變成了展廳。現(xiàn)代的交通樞紐看來對(duì)于這種新的公共空間角色是越來越自信了，它們有理由相信，即使是最行色匆匆的過客，也會(huì)因空間設(shè)計(jì)質(zhì)量與內(nèi)容的提升而在交通樞紐內(nèi)多停留一段時(shí)間，而正是這種剩余停留時(shí)間人次的積累，使得交通樞紐作為公共空間的成色越來越足。

第三個(gè)特性是把交通樞紐的空間當(dāng)成是一種都市景觀進(jìn)行設(shè)計(jì)，全然顛覆掉紀(jì)念性交通空間的傳統(tǒng)。在紀(jì)念性主導(dǎo)的時(shí)代，交通樞紐的設(shè)計(jì)是關(guān)于屋頂、柱子、墻體和立面的，而在都市景觀的時(shí)代，交通樞紐的設(shè)計(jì)只有一個(gè)優(yōu)于任何其他表面的關(guān)注——我們行走移動(dòng)的水平面——地面。在阿納姆中心換乘樞紐的設(shè)計(jì)中，這一關(guān)注造就了一個(gè)令人興奮的延展與纏繞地面體系，其所能承載的移動(dòng)與活動(dòng)類型超乎最初的想像。這可能是源于荷蘭人揮之不去的自行車情結(jié)，也可能是源于建筑師對(duì)流動(dòng)延伸空間的鐘情，無論如何，它給予過客以一種類似公園般愜意的移動(dòng)體驗(yàn)——在車站里消磨時(shí)間，如同在公園里一般？這聽起來真是不壞。

第四個(gè)特性要復(fù)雜得多，雖然在視覺上它最容易識(shí)別，即使在進(jìn)入樞紐空間前。這個(gè)特性就是時(shí)下盛行的直接以交通樞紐為基底，在其上進(jìn)行綜合開發(fā)，即TOD，或交通綜合開發(fā)。根據(jù)不少專業(yè)人士的解釋，直接在交通樞紐上進(jìn)行綜合開發(fā)，集結(jié)高密度的空間，堆迭復(fù)雜的多種功能（包括工作和居?。?，以及采用垂直發(fā)展的類型是最大化利用交通樞紐便利性的靈丹妙藥。東京周邊的高密度區(qū)域是這一模式的先行者（多數(shù)為東京鐵路公司自行開發(fā)），而其顯而易見的固定資產(chǎn)市場(chǎng)吸引力則直接在柏林或深圳的同類建設(shè)中得到了發(fā)揮。一方面，我們必須承認(rèn)在最小的城市足跡上建設(shè)緊湊的、超高密度的微型城市是一種非常進(jìn)步的實(shí)驗(yàn)，另一方面，我們也需要認(rèn)知它的風(fēng)險(xiǎn)。這里的一個(gè)重要問題是在某地進(jìn)行TOD開發(fā)的緣起究竟是什么。如果是增長(zhǎng)的局域人口的剛性需求，那么這一開發(fā)匆庸質(zhì)疑將是對(duì)城市有益的。但如果是僅僅為了獲得最大的市場(chǎng)價(jià)值，那么在相應(yīng)的開發(fā)中，軌道交通的進(jìn)步與革新被過度開發(fā)的貪婪所淹沒也不是不可能的。□

參考文獻(xiàn)/References

[1] Chakrabarti, Vishaan. A Country of Cities: A Manifesto for an Urban America. Metropolis Books,2013:14-25.

[2] Tafuri, Manfredo and Dal Co, Francesco. Modern Architecture/2. Electa/Rizzoli, 1976[1986]:258.

Mobility forms a quintessential part of contemporary life. For any modern metropolitan inhabitant, a significant chunk of daily life is spent on some form of public transportation. Everyone may have a different idea on which form of public transportation works the best. But the consensus of twenty-first century urbanists seems to be that the model of hyperdensity connected by rails/light rails is the most desirable and sustainable[1]. It is also common to see the updating of railway and subway infrastructure being the most popular subject of urban renewal projects, both in developed cities and emerging ones. For visitors and inhabitants alike,more often than not, the railway/subway spaces are becoming the de-facto prime identity-giver to metropolises around the world. The sound, smell,touch and vibe of major rail/light rail transit hubs have therefore become definitive experiences and qualities of our urban lives.

Transit hubs are products of urbanisation back to industrialisation times. Just as cities took a long road to eventually put humans in the centre,transit hubs had been for long a realm of technology and efficiency before finally turning into public spaces. 19th Century railway stations were objects of imperial competitions, with excessive pursuit of stone and cast-iron monumentality. Behemoth canopies and gargantuan spaces made the stations more palaces than hubs. Surprisingly, this tradition of monumentality in transit spaces has survived much longer than the imperial states that created them and have extended all the way up to our time. From old world cities to new progressive municipalities,the adoption of monumental transit hubs seemed to be irresistible. In 20th century Moscow, we saw the extravagance of metro stations as underground palaces. In 21st century emerging Chinese cities,we see the grandeur of hi-speed railway stations. In today's New York, we witness yet another manifesto of monumentality in public transportation, albeit in crystal-clear glass and clean white cladding of aluminium alloy, not stone or cast-iron.

Ironically, the making of transportation hubs as public spaces was initiated in a very unlikely political climate. In the 1920s, Mussolini's policies were fixed and started to dominant Italian urban life. In the years that followed, state sponsored projects, mostly in public infrastructure, became the main measure of stimulation to counter economical volatilities. This nevertheless led to major transformation of old urban centres. In the 1933 competition winning, rationalist project for Florence railroad station, the then young architect team led by Michelucci delivered "the advocates of a new architecture promoted a debate that remained well within the limits of discussions as to specific approaches and ways of working"[2]. And the basic quality of this "debate" and "specific approaches"was the integration of the concourse space, no longer elevated from the urban ground, with typical urban services. Though not as big as many of its counterparts today, this did give a new definition to railroad stations (and to all transportation hubs as well), in which the boundary between a station and a public space is crossed-over.

More than eight decades later, we feel reassured to say that currently, transportation hubs are moreand-more taken by default as public spaces. Although there are a few exceptions, most urban transit centres are taking the experience of the people truly seriously. The humanisation of transportation hubs can be identified through four characteristics.

The first the priority given to slow mobility,with expanded surface area serving pedestrians and bicycles. Typologically, most modern stations and transit centres would deliberately weaken the sense of concourses and lounges, while replacing them with indoor plazas, atriums and streets. This strategy is visible in both new stations and renovated old stations, In the central station of Zurich, the entire old station building is emptied to give room to an indoor public open space, not much different from a conventional city market. The fl exibility and vitality of such a typology can only be a plus to the identity of a 21st century international city.

The second is the inclusion of more recreational and public programs. The inclusion of retails, cafes and restaurant is quite conventional. But the inclusion of galleries, gaming parlours, theatres and libraries is rather intriguing, and is more and more common in European stations. The new central station in Delft, definitely inspired by the renown technological university that resides in the town, accommodates serious displays of cutting-edge renewable energy cars. It does seem that modern transportation hubs are getting more and more confident that passengerson-the-move will spend more time inside the station than their normal transit activity requires, and it is exactly this bold assumption and the related designs that makes passengers staying longer in the station,making it a truer public space.

The third is to design the spaces as urban landscapes, overhauling the traditional monumentality idea of stations/transportation hubs. While monumentality would put emphasis on roofs, columns and walls (facades), urban landscape,instead, would pay primary attention to the surface below our feet. In Arnhem Central Transfer Terminal, this attention has resulted in an amazing network of paths and surfaces intertwining more activities than what is imaginable. Partly driven by the Dutch obsession with bicycles, partly driven by the architects' obsession with flux space, this terminal does give a public park-like experience to all its visitors. More time spent in a station equals to more time spent in a park? Not a bad idea at all.

The fourth is a more complicated one, albeit visually rather distinctive. It is the tendency of developing the station or transit centre itself into a mixed-use complex, under the jargon TOD (Transportation Oriented Development).Accommodating higher density, stacking more program (including working and residential),going vertical is said to be the panacea to take full advantage of the easiest mobility access these transportation hubs provided. Pioneered by developments in ultra-dense areas near Tokyo(mostly by railroad companies themselves), this economically attractive option has seen its offspring in cities like Berlin and Shenzhen. While creating a compact, miniaturised, full-f l edged mini city on an extremely small footprint is a very progressive idea,there are caveats though. The first and the foremost one being the question of what drives a TOD. If it is the increasing demand by a growing population,fine. If it is simply the market, then probably all the good about modern rails/light rails would be overshadowed by the greed of overdevelopment.□