Beyond strategic considerations relating to how public spaces evolve and are regulated, the balance of space types across an urban area, and how to guarantee rights and responsibilities; at a more detailed level, planners are also often the guardians of how new public spaces are created and existing spaces are regenerated. Thus through their plans, ordinances, frameworks and policies, or through discretionary negotiations on development proposals during the regulatory process, planners have the opportunity to set out and implement clear principles for the sorts of public spaces they would wish to see. Whilst every public space will be different, and attempts to define universally applicable principles for ‘good’ public space design are often based on little more than supposition and intuitive analysis (e.g. UN Habitat 2013), extensive empirical testing revealed a number of critical factors that are likely to be important in the design of most public spaces (Carmona and Wunderlich 2012). These concern
How public spaces are clearly delineated from private ones so that they feel and are publically accessible.
How the uses surrounding public spaces contribute to creating engaging places for users.
How spaces can be made more meaningful through the amenities and features they host.
How the opportunity is taken to maximise the potential for a positive social environment in public space.
How a balance between vehicles, pedestrians and other users in public space is set and safeguarded.
How spaces are made to feel comfortable through their ability to foster safe and relaxing use.
How robust public spaces can be created as a consequence of their ability to adapt to changing demands across time whilst remaining distinctive.
The remainder of this paper takes these seven factors in turn and, drawing from the research, suggests in a little more detail why they are important and, in relation to each, which aspects planners might consider.
Delineated public space (clearly public in their use)
The problems associated with creating spaces that are neither clearly public nor private in their use have been well documented in the urban design literature, at least since the writings of Oscar Newman (1973). This has long been a problem in residential areas, but is also apparent in some commercial developments (Fig. 11), whilst some retail schemes can appear overly exclusive and therefore not fully public, or at least not welcoming to all. There remains an important need to carefully delineate the public and private realms of the city, recognising that public spaces in the wrong places can be more problematic than the absence of public space altogether (Fig. 12). Instead, public spaces (including all varieties of pseudo-public space) should be designed to appear welcoming, inviting and visually and physically accessible, avoiding any doubt in users’ minds that they are clearly public, regardless of who owns and manages them. Equally, private spaces for relaxation such as private or communal gardens have an important and quite distinct role that is separate from the shared public parts of the city. Through the way they are designed, these parts of the city should be clearly private, even if visible from the public realm. This is not segregation in the negative sense that it is sometimes viewed as in the literature (e.g. Webster 2001), but merely a positive division between the public and private functions of the city; the careful demarcation between which represents a fundamental quality of good urbanism (Carmona et al. 2010, p. 219).
Engaging public space (designing in active uses)
Whilst buildings, landscape and infrastructure define the physical limits of external public spaces, the land uses surrounding spaces, and those lining the streets leading from spaces, will dictate what sort of places they will be; whether peaceful, gently animated or full of life. At all times it is important to be realistic about what will work and what will not in particular locations, and therefore about what sort of space can or cannot be created. Trying to create a vibrant commercial hub in a quiet residential area (Fig. 13) or a peaceful oasis in a busy urban centre is likely to be unrealistic.
Despite criticisms that public spaces have become over-commercialised and unduly dominated by the pressure to consume (e.g. Hajer and Reijndorp 2001), much of the buzz associated with particularly active spaces will tend to be wrapped up in the activities of consumption of one sort or another—shops, cafes, bars, markets, etc.—and typically these processes animate and enrich public spaces and are welcomed by users (Fig. 14). If the intention is to create such a space then active uses should be carefully designed into the public space from the start, helping to fill them with life and allowing users to engage with them. The importance of getting the use mix surrounding (and within) public spaces right is therefore an early and critical lesson in the public space design process and involves decisions in which planners almost always play a leading role.
Meaningful public space (incorporating notable amenities and features)
Extensive interviews with users of spaces across London suggested that they are primarily concerned with how they experience space—good or bad, engaging or repellent, attractive or ugly—rather than with narrow stylistic concerns associated with the details of their design or whether they are narrowly ‘authentic’ or not; a concern of some of the public spaces literature (e.g. New Economics Foundation 2004). Over time, spaces become more meaningful as users interact with them and they acquire the patina of age and use. Spaces can also become more meaningful by incorporating key historic or landscape features (e.g. existing historic buildings or mature trees—Fig. 15), and by hosting other amenities and features with which users can directly engage (Fig. 16). These might be active, such as big screens, band stands, kiosks, sports facilities, fountains, paddling pools, play equipment, skating opportunities, stages, amphitheatres, lighting displays and so forth. Equally they may be restful, serious or contemplative, such as public art, sculptural furniture, memorials and monuments, reflection pools, flower gardens/displays, wifi hot spots, and so on.
Social public space (encouraging social engagement)
How we design public spaces can make them more or less conducive to social interactions of all types, from large-scale events and festivities, to low key humble encounters, and everything in-between. Rather than a retreat from public space as predicted by some (e.g. Graham and Marvin 2001), the evidence from London suggested that, if conducive to such uses, public spaces still represent the definitive venues for public debate, protest, encounter, collective experience, communication and the rich and varied social life of towns and cities. Detailed observational work revealed that movement in public space predominantly flows along dominant movement corridors or ‘desire lines’ passing right through spaces, and from movement corridors to the active uses on a space and vice versa. In the majority of spaces that are well integrated into the movement network, only a small proportion of users will actually stop within and engage directly with the space itself whilst the majority will pass straight through. Nevertheless, high levels of through movement will generally stimulate high levels of activity on the space, with the highest density of such activities (and social encounters) typically occurring in the gaps between the dominant lines of movement and being drawn to and around key amenities and features (Fig. 17).
Individual spaces (if large enough) can also work successfully as a series of distinct and separate subspaces, each with a different character and purpose and designed to attract different sorts of users (e.g. fountains for children, steps and ramps for skateboarders, alcoves for quiet conversation, and so forth) (Fig. 18). In designing public space, it is as important to consider the desired social outcomes and how the physical space and its context will or will not support them. Whilst particular social outcomes can never be guaranteed (Carmona et al. 2010, p. 133), leaving such outcomes entirely to chance is unlikely to be a successful strategy.
Balanced public space (between traffic and pedestrians)
The challenge of traffic dominance is a perennial problem that continues to blight many public spaces with severe knock-on impacts on their social life (Gehl and Gemzoe 2000). The solution, however, does not have to be banning all traffic. Instead, a subtle re-balancing of space is often all that is required as traffic and pedestrians can harmoniously share public space with mutual benefits to both groups: allowing drivers direct access to and between important urban centres; and providing a background level of animation and surveillance in public spaces. This requires that enough space is given to pedestrians for movement and socialisation; that they are not corralled and kettled (Fig. 19) but trusted to move and navigate freely; and, to enable this, that traffic is slowed sufficiently on roads leading into and through public spaces (Fig. 20).
Comfortable public space (feeling safe and relaxing)
Despite claims in the literature that there has been a general securitisation of public space (e.g. Minton 2009), in reality, security is expensive and arrangements tend to be pragmatically defined to reflect the needs of different types of public spaces. Whilst some very busy spaces (e.g. the forecourts of major railway stations) may need and do possess highly visible security (Fig. 21), most do not. Ultimately, the objective should be the wellbeing and sense of wellbeing of users, and their ability to use spaces in a relaxed and comfortable manner.
Interviews with the users of public spaces in London confirmed the long-held view from Jane Jacobs (1961) onwards that security (or at least a sense of security) is first and foremost determined by how busy spaces are, as active spaces will always seem safer than deserted ones, as will spaces that are well overlooked and clearly visible from the outside. Second, how well spaces are managed also has an impact, with spaces that are clean and tidy and well maintained generally feeling safer than those that are not. Finally, spaces should be relaxing, with opportunities to stop and linger, for example, with good quality, comfortable and preferably moveable formal seating, informal seating opportunities (on steps, kerbs and walls), toilet facilities, soft landscaping and careful consideration given to microclimate (places to sit in the sun, and to shelter from the wind and the rain). Grass, for example, whilst requiring active maintenance, is very popular because it is comfortable, flexible and allows users to position themselves to take advantage of micro-climatic conditions. It is also highly conducive to relaxation, play and social engagement (Fig. 22).
Robust public space (adaptable and distinct in the face of change)
Finally, the success of public spaces will depend on shaping places which, through their robust design (simple, uncluttered and with resilient natural materials, trees and planting), and background level of activity, are able to adapt and change over time in a manner that can withstand the sorts of homogenisation pressures that are so derided in the literature (e.g. Boyer 1993) and which still feel distinct, welcoming and rooted in the local context. In the short term, this means spaces that can adapt to different uses and activities, perhaps at different times of the day (somewhere for workers to lunch or for children to play—Fig. 23), throughout the week (a market on a Monday and, without feeling deserted, peace and quiet on a Sunday), or across the year (concerts in the summer and ice skating in the winter—Fig. 24a and b). In the long term, it will mean successfully adapting to changes in the uses that surround the space or to the demands placed on spaces by changes (yet unknown) to society and technology. It will also mean design solutions that reflect the realities of management routines and the budgets available for the upkeep of public space, with materials and features that are able to age gracefully and in a timeless manner.