Recognition of Uncertainty in Planning——Rationalism in Recognizing and Responding to Uncertainty in Urban Planning (1)

Abstract: There has been considerable discussion in the history of planning about the problem of uncertainty in planning, leading to a series of excellent ideas and methods. Summarizing these historical experiences is of great significance for understanding and solving the problem of uncertainty in complex urban systems. This paper categorizes planning uncertainty into uncertainty in law cognition, uncertainty in planning goals, and uncertainty in planning intervention. Further, from the perspective of rationalism, it traces the recognition of and response to uncertainty in planning since the 1960s. It posits that rationalism has undergone phases including instrumental rationality, bounded rationality, communicative rationality, and neo-rationalism, each leading to various theories and planning paradigms like comprehensive planning, scenario planning, communicative planning, and complex adaptive systems for recognizing and resolving planning uncertainties. Summarizing these response paradigms, the paper suggests that future planning in China should acknowledge the coexistence of certainty and uncertainty. Methodologically, it advocates for a multi-perspective theoretical framework in planning formulation, implementation management, and social governance.

Keywords: Uncertainty, Rationalism, Urban Planning, Bounded Rationality

1. Introduction #

Urban planning has played a crucial role in guiding and driving urban construction and development in China over the past decades. However, planning often faces the embarrassing situation of being “ineffective” when confronting the uncertainty of future urban development and related demands within the city. Some scholars have even pointed out that general plans are always “outdated,” and control plans often “uncontrollable” [1]. However, the recognition of uncertainty in urban planning has a long history, and a series of solutions and methods have been developed. Summarizing the outstanding ideas and methods from history for solving uncertainties in planning is significant for understanding the uncertain characteristics of cities as complex systems and addressing these uncertainties.

Among the many philosophical reflections on solving urban uncertainties, rationalism, as one of the most important core ideas in modern urban planning theory, has always played a significant role in recognizing and addressing the phenomenon of urban uncertainty. Rationalism, as the cornerstone of modern philosophy and science [2], has been integral to the development of modern urban planning theory and methodology, even dominating Western planning theory and practice at one point [3]. Rationalism has evolved from the Cartesian era’s demand for clear and precise cognition of laws to the recognition of uncertainty through bounded rationality and communicative rationality, and into the new century with the proposal of neo-rationalism. This evolution corresponds to the shift in urban planning from ignoring uncertainties to recognizing and passively responding to them, and then to a decision-making approach that encompasses tolerance and active intervention.

In summary, this paper discusses the evolution of thought and intervention methods in planning when facing the complex and uncertain system of the city, from the perspective of rationalism’s recognition of and response to uncertainty, providing positive references and implications for future urban planning in China.

2. Recognition of Uncertainty in Planning #

To clarify the content and framework of the analysis, this article first categorizes the uncertainty in planning into three aspects: uncertainty in the cognition of urban laws, uncertainty in urban planning goals, and uncertainty in urban planning intervention. The uncertainty in law cognition highlights the inherently indeterminate characteristics of cities, representing the uncertainty of the decision object. In contrast, the latter two focus on the decision-making and implementation processes in planning, representing the uncertainty of the decision subject.

2.1 Uncertainty in the Cognition of Urban Laws #

The city is a complex, open mega-system and an adaptive system. The laws governing its system development include uncertainties. This uncertainty in law cognition can be further divided into three parts: Firstly, the insufficient understanding of existing laws. The complex system has numerous laws, and discovering, verifying, and mastering these laws require appropriate tools and methods. Our current understanding of urban laws is still quite insufficient, and even the tools and methods needed to discover these laws are not mature enough. This uncertainty can be reduced or even eliminated through continuous research and discovery of urban laws.

Secondly, the limited predictability. Complex science indicates that rapidly changing mega-systems do not always have inevitable and regular development paths [4]. Complex systems are highly sensitive to initial conditions, so they often only allow for short-term behavior predictions, not long-term outcomes [5]. The long-term development of cities is currently unpredictable in scientific theory, representing an insurmountable uncertainty.

Thirdly, instability. The development process of cities inevitably experiences sudden changes. Large events, major projects, and significant shifts in city decisions can lead to significant deviations from the original development trajectory, causing substantial discrepancies between planning forecasts and actual development. These sudden and imbalanced changes are often unpredictable in planning, and the uncertainty brought about by instability will persist for a long time.

2.2 Uncertainty in Urban Planning Goals #

The primary source of uncertainty in urban planning goals lies in the guiding values and related policies of planning at the formulation and implementation levels. John Friend pointed out the need to solve coordination problems among different decision-makers’ policies in planning, requiring consensus among all parties to implement strategic methods [6]. Peter Hall further noted that many uncertainties in the planning environment stem from uncertain guiding values or policies [7]. In China’s planning system, there are often conflicting planning goals between the planning subject government and planning objects like the market and stakeholders. The failure to clearly coordinate these conflicts makes the planning’s value orientation unclear, leading to a plan that is “uncertain for whom it is made,” ultimately encountering resistance in implementation and difficulty in gaining acceptance.

Additionally, the value orientations of planning subjects and objects often change with the planning context, making the value consensus reached during planning formulation different from that during implementation. The lag in spatial intervention means that space inevitably lags behind actual needs, turning the planning goal into a hypothetical rather than a real target. For example, London had a positive assessment of the economic development brought by the Olympics when bidding for the Games, and planned accordingly. However, the economic downturn during the actual Olympics turned the event into a burden rather than an ideal vision for the government departments [4]. Such changes in goals are common in today’s rapidly developing world, and obviously, the overall social development changes far exceed the predictive scope of planning.

2.3 Uncertainty in Urban Planning Intervention #

The uncertainty in planning intervention is first reflected in the limited nature of decision-making information. In the context of the dispersion and complexity of social knowledge, it is almost impossible for decision-makers to consider all influencing factors cost-effectively in a neoclassical rational calculation [8], making the planning decision basis always incomplete and limited. Consequently, it is difficult for decision-makers to make entirely certain judgments during intervention decisions, leading to a tendency among some government decision-makers in China to opt for relatively short-sighted decisions or decisions based on subjective preferences.

The uncertainty of intervention is also reflected in the complexity of its impacts. On the one hand, it is difficult to fully anticipate all the results of planning intervention in the city. The complexity of the city means that an intervention often yields results entirely unforeseen in the initial planning phase, and in some cases, results contrary to expectations. On the other hand, it is difficult to ascertain the effectiveness of the intervention. In the implementation of planning, the planning intervention’s lack of involvement in the approval and implementation process involving multiple parties and balancing interests can lead to significant differences between the implementation results and the ideal expectations, even causing the implementation of the overall urban planning intention to face difficulties.