2 Crime Place Theories and CPTED Principles

Numerous theories seek to explain why urban crime occurs in certain places; basically they can be grounded into three primary theories. The first one is Rational Choice Theory, which claims that the decision to commit a crime depends on personal needs and situational factors such as surveillance and the possibility to be caught. The second theory is Behavioral Geography Theory that considers places closer to the offender’s work or residency are at higher risk than areas not within the offender’s daily route, in other words, referring to accessibility[12]. The last theory is the Routine Activity Theory, which looks at the interaction of three factors: the availability of an attractive target, the absence of guardians, and the presence of motivated offenders[13]. The environmental design has proven the ability to intervene two of them: the physical target and the offenders’ exposure.

Regarding the urban crime location, Paul Cozens and Terence Love summarized the places where crimes occur into 5 types: crime generators, crime attractors, crime detractors, crime facilitators, and crime precipitators. Crime generators are places that attract a mass of people, some with undetermined

motivations to offend that can change to criminal acts. Crime attractors are places that are appealing to perform offending actions. Crime detractors are places that have few people, thus to encourage use by potential offenders. Crime facilitators are places that contain things that assist offenders such as firearms, gangs, alcohol, and drugs. Finally, Crime precipitators are places where its physical combinations push non-offenders to commit crimes; for example, public urination due to the lack of public toilets[11].

This research concentrates on CPTED, an approach that seeks to optimize prospects for surveillance, clearly define boundaries, and create and maintain a positive image of the urban area, all to reduce opportunities for offending. Within CPTED recommendations, offenders would be more visible and

would feel more at risk of being apprehended[11]. Besides offering design interventions, CPTED provides management strategies to support its cause, such as amplifying the sense of ownership

and social control by well-maintained and appropriately used urban environment to hinder offenders. CPTED proposes 7 concepts for design: territoriality, surveillance, image and milieu, geographical juxtaposition, access control, legitimate activity support, and target hardening[11]. Project for Public Spaces added legibility and physical permeability. The former refers to the clarity of the environment and the degree to which a space is understandable, while the latter means to what extent an environment allows people to alternate choices of movement in it. Sufficient lighting, visible entrances, less dense foliage, fences, and active space use are recommended by CPTED to increase the safety of the public spaces[3][9][12].

2 犯罪场所理论和CPTED原则

 许多理论都聚焦于分析城市犯罪多发于某些特定地点的原因，它们大致源于三种基本理论：一是“理性选择理论”，该理论认为实施犯罪的决定取决于个人需要和情境因素（如监视情况和被抓住的可能性）；二是“行为地理学理论”，该理论关注犯罪场所的“可达性”，认为犯罪者更倾向于在其工作地、居住地等日常活动区域附近作案[12]；三是“日常活动理论”，主要关注三个因素的相互作用：能够接近有吸引力的目标、缺乏有效监视，以及有犯罪动机者[13]。环境设计能够对日常活动理论中的两个因素产生影响，即犯罪目标和犯罪者的暴露程度。

 保罗·科岑斯与特伦西·拉夫将犯罪发生场所归纳为5种类型：产生犯罪型、吸引犯罪型、转化犯罪型、恶化犯罪型和临时起意型。产生犯罪型场所可吸引大量人群，其中便包括犯罪动机尚不确定但可能实施犯罪的人；吸引犯罪型场所是指能激起人的犯罪欲望的场所；转化犯罪型场所则指那些少有人来往、可能供潜在犯罪者实施犯罪的场所；恶化犯罪型场所是指那些可供犯罪者藏匿枪支、同党、酒精和毒品的场所，可帮助他们实施犯罪；临时起意型场所的物质环境会促使本无犯罪意图者犯罪，如在没有公共厕所的环境下随地小便的行为[11]。

 本研究关注的CPTED方法旨在通过扩大监视者视野、建立明确的场所边界，以及创建和维护城市空间的正面形象来减少犯罪机会。在按照CPTED建议设计的场所中，犯罪者会更容易暴露并更有被捕的危机感[11]。除了设计建议外，CPTED还为保障设计效果提供了相应的管理策略建议，例如通过对城市环境的妥善维护与恰当使用，充分营造“为人所有、为人所用”的氛围，从而减少犯罪的发生。CPTED提出了7个设计原则，即空间领地性、监视形象和周边环境、地理环境、出入口控制、合法活动引导，以及目标强化[11]，非营利组织“公共空间工程”在此基础上又增加了可理解度和物理通透性—可理解度是指环境空间结构的晰度和易识别度，物理通透性则是指在某一环境中人们可自由选择如何活动的程度。根据CPTED的建议，充足的照明、可见的入口、适度疏朗的绿植、栅栏和积极的空间使用均有助于提高公共空间的安全性[3][9][12]。

3 Space Syntax Theory and Crime Prevention

3.1 Space Syntax

Space syntax is a kind of analytical urban model, and a quantitative method aiming to capture the quality of urban environments with a set of measures for space configuration and for quantifying and analyzing the properties of architectural and urban spaces[9]. It was first developed in the 1980s at the Bartlett Unit for Architectural Studies, University College London by Bill Hillier and Julienne Hanson[13]. In Hillier’s book Space is the Machine: A Configurational Theory of Architecture, space syntax is defined as an objective way to interpret human behaviors and social activities from a spatial and morphological configuration point of view[14][15]. The theory postulates that the system structure of space in which various activities happen can affect users’ movement and avoidance, shape their uses, and produce social relations; therefore, the spatial configuration must be analyzed and understood[2][15]. Space syntax privileges the topological properties of a space over its geography, as people are likely to move or behave based on topology under Graph Theory[16]. It delivers tools to analyze the linguistic characteristics of space, such as integration, configuration, user choice, visibility, and isovists.

3 空间句法理论与犯罪预防

3.1 空间句法

空间句法（space syntax）是一种城市分析模型，可对城市环境的 品质进行定量描述，包含一系列用于量化和分析建筑及城市空间布局 的指标[9]。空间句法理论由英国伦敦大学学院巴特莱建筑学院的比尔·希里尔和尤利安·汉森于20世纪80年代首次提出[13]。希里尔在《空间即机器：建筑的布局理论》一书中将空间句法定义为从空间和形态学布局视角解释人类行为及社会活动的一种客观方式[14][15]，认为对空间布局进行分析与理解极为必要，因为空间的系统结构会影响使用者在其中的活动和回避情况，进而决定其对空间的使用及社会关系的形成[2][15]。空间句法理论还认为空间的拓扑属性比地理特征更为重要，因为人们更倾向于遵循基于图论的拓扑学规律来使用空间[16]。空间句法还提供了一系列工具来分析空间的语言学特征，如整合性、布局、使用者选择、可见性及视域等。

3.2 Impacts of Space Configuration on Crime

The term spatial configuration refers to “a relation affected by the simultaneous co-presence of at least a third element and possibly all other elements in a complex”[14]. Thus, spatial configuration is a set of relations between spaces that exist at a particular time, which may enable or limit the possibility for visual and physical linkages. Spatial configuration is responsible for shaping cognition, while over a time and certain circumstances, cognitive constructs shape spatial configuration. Moreover, spatial configuration is able to alter the attractiveness of the environment (target) and the opportunity (the absence of a capable guardian) as mentioned in the Routine Activity Theory. In addition, it can control territoriality, surveillance, access control, and target hardening in the CPTED approach (Fig. 1), thus to be widely used in the domain of crime prevention.

A considerable body of research devoted efforts to investigate the relationship between the occurrence of criminal events and spatial configuration, mainly in residential areas or at a city scale[9]. Studying crime settings can help understand crime events and gain more knowledge about configurations that are highly connected with particular types of crime such as burglary, street robbery, drug dealing, and theft[4]. Studies have shown that illegal activity is intrinsically linked to pedestrian flows, accessibility, and permeability of the place where crime occurs[17]. Generally, there are two competing schools of thought on how spatial configuration may influence crime and community safety. The first, driven by “new urbanism school” and influenced by Jane Jacobs, calls for open and permeable mixed-use environments, whereas the opposition emphasizes the importance of control over people’s territory like Oscar Newman’s theory. Space syntax analysis has shown that both the theoretical standpoints have their strengths and weaknesses[17]. An example supporting the new urbanism school is a study based in London, which showed that locations less likely to be surveyed by police patrol were associated with drug crime[17]. In contrast, Ray Jeffery claimed that crime could be prevented by creating urban spaces with well-defined boundaries, wellcontrolled access points, and well-maintained landscapes[5], and another study in a residential area in Canada found that an increasing accessibility to secondary and arterial streets is associated with an increase in crime[18], both supporting the second vision.

Visibility is an essential factor in enhancing space security and the sense of safety, which is also affected by spatial configuration. Different degrees of visibility, natural surveillance, and co-presence also impact crimes[17]. Higher visual permeability can make people feel safer as they can see other people around with clear sightlines, which allows for identifying sources of threat. Visual permeability can be negativity affected by the presence of shrubbery vegetation, fences, walls, sharp corners, storage sheds, and buildings[19]. Several studies confirmed that low, dense vegetation in parks obstructs views and offers criminals a place to hide, thus reducing the sense of safety[20]. Yet, some other studies have found that vegetation is associated with decreased crime rates due to higher attractiveness to people. Meanwhile, streets and unpaved areas with no vegetation are often seen as “no man’s lands,” which would discourage social interaction, making it easier for criminals to go unnoticed. In contrast, well-maintained vegetation might reduce crime since it can be seen as a “territorial marker” or a “cue to care”[21]. Generally, this discrepancy can be explained by differences in the types of vegetation analyzed, as the positive correlation with crime appearance were found more in low, dense vegetation;

however, the contradicting results might be concluded to moreopen areas[21].

3.2 空间布局对犯罪的影响

“空间布局”（spatial configuration）是指两种元素之间受同时存在的其他至少一种元素，甚或全部其他元素影响的相互关系[14]，即某一时间点上空间之间存在的一系列关联，而这些关联不一定是肉眼可见的或物理层面上的。空间布局会影响人们的认知，随着时间的变化且在特定条件下，认知要素反过来也会影响空间布局。此外，空间布局能够改变日常活动理论中的环境吸引力（即目标）及犯罪机会（即缺乏有效监视），并影响CPTED中空间领地性、监视、出入口控制和目标强化等相关设计（图1），因此空间布局在犯罪预防领域得到了广泛重视。

已有大量研究探讨了犯罪的发生与空间布局之间的关系，但主要关注于居民区或城市尺度[9]。对犯罪环境的研究有助于理解犯罪事件，并深入了解与特定犯罪类型（如入室盗窃、街头抢劫、毒品交易和偷窃）高度相关的空间布局特征[4]。例如，有研究指出，非法活动与其发生地点的行人流量、可达性和渗透性具有内在联系[17]。关于空间布局如何影响犯罪和社区安全主要存在两种观点：其一受简·雅各布斯影响并由“新城市主义派”引导，提倡开放、可渗透的混合功能空间；另一种观点则以奥斯卡·纽曼的理论为代表，强调对公共领域加强控制。空间句法分析研究印证了这两种观点 [17]：一项在伦敦进行的研究发现，巡警巡视较少的地点与毒品犯罪事件存在相关性，这与新城市主义学派的观点相一致[17]；另一方面，雷伊·杰弗里认为建立具有明确边界、出入口控制有序且景观维护良好的城市空间有助于预防犯罪[5]，而另一项针对加拿大某居民区的研究亦发现支路与主干街道的可达性与犯罪率呈正相关[18]，二者均印证了第二种观点。

可见性是增强空间安全性及人类安全感的重要因素，其同样受空间布局影响。可见性、自然监视和共现程度的不同也会对犯罪产生不同的影响[17]。较高的视线通透性可以使人们清晰地看到周围的其他人并发现潜在的威胁来源，从而感到更加安全。茂密的植被、栅栏、墙体、尖锐的拐角、仓储构筑，以及建筑物的遮挡均会影响视线通透性[19]。一些研究表明，公园内低矮且茂密的植被会遮挡视线、为犯罪者提供藏身之所，从而降低人们的安全感[20]。然而，也有一些研究发现空间中的植被可以吸引更多的使用者，从而降低犯罪率；同时，没

有植被的街道和无地面铺装的区域通常被视为“无人地带”，由于缺少社交活动，犯罪者在这些空间中更不易被发现。相反，维护良好的植被往往意味着该区域为人所有或处于管护之下，因而有助于减少犯罪[21]。尽管不同的植被类型与犯罪发生之间的关联可能存在差异，但整体而言，低矮且茂密的植被与犯罪发生之间的正相关性更为显著；相反，场所的空间开阔度与犯罪发生之间存在负相关性[21]。