Perceived Effectiveness of Crime Prevention Through Environmental Design (CPTED) Strategies: Role of City Departments and Community Involvement

ABSTRACT

Research has previously addressed the effectiveness of crime prevention through environmental design (CPTED) strategies in reducing the fear of and incidence of crime. However, existing works on this topic are not comprehensive. Few studies compare important aspects of CPTED methods that may influence effectiveness of CPTED, such as which city departments are responsible for compliance with particular methods as well as the community’s level of involvement in implementation of the method. This study uses data from the National Institute of Justice’s Data Resources Program, focusing on a study titled “Security by Design: Revitalizing Urban Neighborhoods in the United States,” a survey collected from the mayors of 323 different cities between the years of 1994-1996 (Scrimger, 2005). The survey data is analyzed for the perceived effectiveness of five different CPTED strategies and possible associations with the city departments responsible for implementation. Additionally, this study considers the role of phase of implementation, city population, form of government, and level of community involvement. While results do not suggest a strong relationship between city departments responsible for implementation of a particular CPTED method and perceived effectiveness, some findings indicate that more well developed CPTED strategies are perceived to have greater effectiveness at reducing crime than less developed strategies. Lastly, community-initiated CPTED strategies in urban beautification are associated with higher perceived effectiveness than those that are not community-initiated.

Conceptual Framework

Crime prevention through environmental design (CPTED) “refers to the proper design and effective use of the built environment for reducing the fear and the incidence of crime,” (Jeffrey, 1969; Crowe, 2000; as cited in Sohn, 2015, p. 86). Jacobs (1961) and Newman (1972) laid the groundwork for this method: Jacobs, through her insights about the role of the ‘natural surveillance’ that works as a byproduct of vibrant streetlife, and Newman, through ‘Defensible Space’ theory. Both Jacobs and Newman emphasized the idea of natural surveillance, however, ‘defensible space’ is primarily characterized by low-density residential environments in which residents can easily identify “strangers” (Schneider, 2005; Sohn, 2015). Underlying these works is the idea that the physical environment plays a role in creating or diminishing opportunities for crime, and it is out of these works that the main four principles of CPTED are established. They include (1) territoriality, which demarcates public space from private space, (2) natural surveillance, which ensures that an area is easily observable by adjusting physical features, (3) activity support, or the encouragement of outdoor activities by nature of public space, and (4) access control, which involves mitigating possible offender’s access to potential crime targets (Sohn, 2015).

Several studies have attempted to measure the effectiveness of CPTED methods, to varying degrees of success. Schneider (2005) describes this difficulty: “The crime-environment connection is so complicated by site features and surrounding elements (both natural and built) that [measuring effectiveness depends] upon ‘how you define key terms, how rigorous is the proof you demand, and how complete an answer you seek’,” (p. 273). One case study by Minnery and Lim (2005) implemented a CPTED measurement scale in the City of Gold Coast in Queensland, Australia, in addition to a social attitude survey to test some assumptions about CPTED effectiveness. They ultimately found that fear of crime is unrelated to CPTED strategies, offering the suggestion that fear of crime is more closely tied to social and personal relationships with those in one’s community. They did find that at the household and street levels, high levels of CPTED implementation correlated with lower levels of crime victimization (Minnery & Lim, 2005). Another study by Sohn (2015) examines the relationship between CPTED measures at the neighborhood level in Seattle in mitigating residential crime. He collected crime incident reports filed by the Seattle Police Department, used GIS techniques to map out CPTED measures, and compared the two datasets based on location. Three major findings came out of this work: first, “that land use diversity has an adverse effect on the prevention of residential crime,” (p. 91), second, “that improving street connectivity by constructing more intersections in the street network increases residential crime,” (p. 91), and third, that “increases in bus-stop density and street density in neighborhoods were negatively related to crime,” (p. 92). This third finding is of particular importance in that it provides clear, empirical evidence that CPTED strategies can be effective.

In terms of the effectiveness of various CPTED strategies, there may be a difference between those implemented by city governments versus those implemented by residents themselves. In a study conducted by Stewart et al. (2019), researchers examine resident-led beautification of vacant lots and the role of this work in helping communities create place identity. They chose to look specifically at a vacant lot repurposing program in Chicago, where they conducted focus groups with residents followed up by a questionnaire. They found that “Across the three focus groups, a consistent narrative was that ownership and caring for one’s property transformed vacant lots from ‘breeding grounds for unwanted behavior,’ to a neighborhood that is ‘friendlier, nicer’ and shows more respect for one another and the vacant lot,” (Stewart et al., 2019, p. 204). “These quotes speak about the residents’ desire to change the narrative about their neighborhoods, from highlighting degradation and crime, to a new one that breathes hope for health and connection with others,” (p. 206). The researchers address that urban beautification can sometimes be viewed as a superficial solution to serious environmental and social problems (Roman et al., 2018, as cited in Stewart et al., 2019). However, in the case of resident-led beautification, there is real potential for building meaningful connections between community members. Semenza et al. (2006) supports this work by examining the implementation of “ecological interventions” in Portland, which included community-designed street murals, public benches, planter boxes, information kiosks with bulletin boards, and trellises for hanging gardens. Ultimately, their evaluation suggests that “mental health and a number of social indicators increased in the course of improving the neighborhood,” (p. 16).

It is also important to note that resident-led efforts may not work for all CPTED strategies. Schneider (2005) writes that “a key issue in the effective implementation of community planning and design is that citizens feel they ‘own’ the solutions to problems,” (p. 276). In other words, resident-led initiatives can also be the source of conflict particularly in regard to what may be considered “public” space. However, in terms of urban beautification, this can be a positive feature in that residents feel motivated to maintain beautification efforts. Other types of neighborhood crime prevention efforts can also be more effective when residents feel ownership over their community. Levine (1986) writes about a community-led crime prevention effort in Cambridge, Massachusetts, that began out of a resident-led efforts to keep hedges trimmed in after an influx of muggings that occurred in the area. If hedges were kept trimmed, the community would increase their opportunities for ‘natural surveillance,’ one of the four major components of CPTED. The community then took this effort to the next level with nightly neighborhood watches, and within a year, the crime wave was reversed. 

While the literature shows some empirical evidence indicating the effectiveness of CPTED strategies overall, and particularly the effectiveness of resident-led and maintained CPTED strategies, there have been few studies that indicate effectiveness as it pertains to who is responsible for implementation and compliance with CPTED strategies. According to Clancey et al. (2018), “there is an ongoing debate in the literature regarding who should be responsible for the delivery of CPTED - the police or built environment professionals, such as planners,” (p. 140). They go on to state that “Internationally, the responsibility for the delivery of CPTED has tended to fall to the police despite a range of approaches to crime prevention with mixed results,” (Paulsen, 2012, as cited in Clancey et al. 2018, p. 151). Further research is needed to determine how effectiveness of CPTED method correlates with who is responsible for compliance with the method, which may help justify who should ultimately deliver and maintain CPTED strategies in the future.


This study attempts to support the above literature with the following questions:

  1. Is the perceived effectiveness of CPTED strategies associated with the type of city department responsible for implementing them?

  2. How do different levels of community involvement with the strategy change perceived effectiveness, if at all? 

Hypothesis 1: Proactive city departments (such as built environment professionals) that are responsible for CPTED implementation will be associated with higher levels of perceived effectiveness of the method when compared with reactive city departments (such as police departments) that are responsible for CPTED implementation.

Hypothesis 2: Cities with communities who are involved with the implementation of CPTED strategies will be associated with higher levels of perceived effectiveness of these strategies when compared to cities with communities who are not involved.


Data and Methods

The following study uses data from the National Institute of Justice’s Data Resources Program, focusing on a study titled “Security by Design: Revitalizing Urban Neighborhoods in the United States,” a survey collected between the years of 1994-1996. The survey’s aim was to collect data on the types of CPTED methods utilized by cities with a population of 30,000 or larger, the degree to which these methods were utilized, and the perceived effectiveness of these methods. A secondary goal of the survey was to help identify trends in “security by design” methods, which is justified through the theory that effective design in the built environment can help reduce both the fear of and incidence of crime.

The United States Conference of Mayors (USCM) mailed the survey to the mayors of 1,060 cities over the years of 1994-1996, receiving a total of 323 responses. The survey is broken down into five different major strategies that cities use within CPTED practices (the sixth strategy included on the survey allowed the respondent to fill in their own). The strategies that are analyzed include: (1) zoning ordinances and building codes; (2) the process in place to review proposed design/plan developments in terms of potential crime/security issues; (3) the process in place for managing public facilities; (4) whether the city uses traffic diversion and control, and (5) ordinances or policies regarding urban beautification. Each section/strategy includes a question or two that ask for further details about the strategy, and follow up with questions (where relevant) on who is responsible for enforcing the strategy, whether the strategy is mandatory or optional, if experts (such as architects, landscape architects, or urban planners) weigh in, whether the community is involved, and the overall perceived effectiveness of the strategy.

Dependent Variable: Perceived Effectiveness of CPTED Methods
The survey respondents were asked to rate the effectiveness of each CPTED strategy on the following scale: (1) Not effective, (2) Somewhat effective, and (3) Very effective. Very few responses were collected in which the effectiveness of a particular CPTED strategy was rated as “(1) Not effective”, so these responses were combined with “(2) Somewhat effective” in the data. Respondents were also given a few lines to elaborate on how they evaluated effectiveness, however, these responses were not included in the publicly available data set.


Table 1: Descriptive Statistics, Dependent Variable

Department Responsible for Compliance

%

N


Strategy #1: Zoning Ordinances and Codes
     Somewhat effective
     Very effective


Strategy #2: Plan/Design Review
     Somewhat effective
     Very effective


Strategy #3: Managing Public Facilities
     Somewhat effective
     Very effective


Strategy #4: Traffic Diversion and Control
     Somewhat effective
     Very effective


Strategy #5: Urban Beautification
     Somewhat effective
     Very effective



75.86%
24.14%



58.59%
41.41%



51.32%
48.68%



63.53%
36.47%



44.60%
55.40%



145



99




76




85




139

Independent Variable: City Department Primarily Responsible for CPTED Method
Survey respondents were asked to name the city department responsible for each CPTED strategy, with potential responses including the mayor’s office, fire department, public works or planning department, city manager, economic development, police department, building department, parks and recreation, zoning department, city attorney, or community development. Respondents were also asked if other offices were involved but did not have primary responsibility, and were given the option to fill in a different department if the correct department was not provided.

For the purposes of the following analyses, the city departments were converted to Reactive Departments (police department, fire department, city attorney, parks and recreation, zoning department) versus Proactive Departments (mayor’s office, public works, planning department, city manager, economic development, building department, or community development). Reactive departments were departments considered to address violations of the CPTED strategies, while proactive departments were considered to be those who may be directly involved in implementing the strategy itself. Reactive departments were coded as “1” (reference category), proactive departments coded as “2”, and departments that were coded as “Other” in the original dataset are coded as “3”.


Table 2: Descriptive Statistics, Independent Variable

Department Responsible for Compliance

%

N


Strategy #1: Zoning Ordinances and Codes
     Reactive Departments
     Proactive Departments
     Other


Strategy #2: Plan/Design Review
     Reactive Departments
     Proactive Departments
     Other


Strategy #3: Managing Public Facilities
     Reactive Departments
     Proactive Departments
     Other


Strategy #4: Traffic Diversion and Control
     Reactive Departments
     Proactive Departments
     Other


Strategy #5: Urban Beautification
     Reactive Departments
     Proactive Departments
     Other



12.41%
54.48%
33.10%



8.08%
74.75%
17.17%



17.11%
60.53%
22.37%



37.65%
38.82%
23.53%



29.50%
39.57%
30.94%


145





99





76





85





139

Control Variables: Phase of Security by Design, City Population, and Form of Government
The respondents were asked to characterize their city’s overall phase of security by design as (1) in early development stages (reference category); (2) mature effort but with room for growth; and (3) comprehensive and strongly supported. Other responses offered include “under consideration” and “other”, however these responses were dropped in the analysis because it could not be determined if any CPTED strategies had been implemented at all in cities with these responses. This variable was selected as a control because the development phase of CPTED may play a role in effectiveness: for example, assuming that CPTED strategies are effective at all, a city with more developed CPTED strategies may show higher effectiveness. Individual responses on each city’s population were also used as a control and re-coded into five categories: (1) under 50k (reference category); (2) 50-100k; (3) 100-150k; (4) 150-200k, and (5) 200k and over. Population was considered because differently-sized cities may have different needs when it comes to crime prevention. Lastly, form of government was included as a control with the following categories: (1) strong mayor-council (reference category); (2) weak mayor-council, and (3) manager-council. “Commission” was also an option for this question in the original dataset, but was dropped from analysis because for all strategies, fewer than 5% of respondents reported this as their form of government. Form of government was included as a control because the surveys were collected from the mayors of different cities, and a mayor with less power may be less aware of perceived effectiveness of CPTED methods. (Note: For the control variables listed in this section, N = 204, but the analytic sample size varies by dependent variable.)


Table 3: Descriptive Statistics, Control Variables: Phase, Population, Form (N = 204)

 

%

 


City's Phase of Security by Design
     In early development stages
     Mature effort but with room for growth
     Comprehensive and strongly supported


City Population
     Under 50k
     50-100k
     100-150k
     150-200k
     200k and over


City's Form of Government
     Strong mayor-council
     Weak mayor-council
     Manager-council



31.37%
41.67%
26.96%



26.57%
33.82%
13.24%
10.29%
16.18%



38.24%
7.35%
54.41%


 





 





 




Control Variables: Community Involvement
Strategy #4: Traffic Diversion and Strategy #5: Urban Beautification also required indication on whether the community was involved with the programs and to what degree. The following questions were treated as dummy variables within the regressions: whether the community initiated the strategy, whether the community helped in planning the program, whether the community assisted in management/oversight of the program, or whether the community was informed of the program. (Note: For the control variables listed in this section, N = 96, but the analytic sample size varies by dependent variable.)


Table 4: Descriptive Statistics, Control Variables: Community Involvement (N = 96)

Level of Community Involvement in Strategy

%

 


Strategy #4: Traffic Diversion
     Community is involved
        Yes
        No

     Community initiated
        Yes
        No

     Community helped plan
        Yes
        No

     Community assists in management/oversight
        Yes
        No

     Community was informed of program
        Yes
        No


Strategy #5: Urban Beautification
     Community is involved
        Yes
        No

     Community initiated
        Yes
        No

     Community helped plan
        Yes
        No

     Community assists in management/oversight
        Yes
        No

     Community was informed of program
        Yes
        No



91.67%
8.33%



52.08%
47.92%



47.92%
52.08%


26.04%
73.96%


42.71%
57.29%

 

84.42%
14.58%


33.33%
66.67%


45.83%
54.17%


31.25%
68.75%


44.79%
55.21%


 





 





 





 

Analytic Strategy

Linear probability models (LPM) are used in this study. Cases are dropped for missingness for each strategy, and robust standard errors are used to address heteroskedasticity. Logistic models were also used to support results of all linear probability models. The logistic models and linear probability models were compared using a correlation matrix and it was found that there were no substantial differences between the results of the two models. For all 5 strategies, model 1 assesses the probability that the department responsible for enforcing the strategy is related to effectiveness of the strategy. Model 2 conducts the same analysis but adds the control variables: phase of CPTED implementation, city population, and form of government in the city. For strategy 4 (traffic diversion) and strategy 5 (urban beautification), variables regarding community involvement level (i.e., involved, initiated, helped plan, assisted, was informed) were added.


Results

Table 5: Linear Probability Model for Strategy #1: Effectiveness of Zone Ordinances/Building Codes (N = 145)

 Title

Model 1

Beta

Model 2

Beta


Department Responsible for
Compliance with Strategy
     Proactive Departments

     
Other

Ref Category: Reactive Departments


City's Phase of CPTED
Implementation

     Mature with room for growth

     Comprehensive

Ref Category: In early stages


City Population
     50-100k

     100-150k

     150-200k

     200k and over

Ref Category: Under 50k is reference
category


Form of Government in City
     Weak mayor-council

     Manager-council

Ref Category: Strong mayor-council
is reference category


Y-intercept


R-squared

 


.061
(.101)
.125
(.111)






























.167

.009

 




.071

.137




.074
(.104)
.154
(.106)




.037
(.080)
.304**
(.094)



.214*
(.091)
-.322**
(.100)
-.201
(.129)
-.173
(.127)




-.045
(.121)
.020
(.078)



.189

.171




.086

.169





.041

.331




-.238

-.248

-.139

-.143





-.029

.024



Heteroskedasticity-consistent robust standard errrors used in parentheses
*** p < 0.001, ** p < 0.01, * p < 0.05

In Table 5, the effect of the department responsible for enforcing the CPTED method of zone ordinance/building codes on perceived effectiveness is not significant in either model. However, when controls including a city’s phase of CPTED implementation, city population, and form of government in the city are added, both the city’s phase of CPTED implementation as well as the city population show significance (p < 0.001 for both “Comprehensive” and “Other” phases of implementation, p < 0.05 for “50-100k” and p < 0.01 for “100-150k” in population size). The r-squared value for the model with controls is .347, indicating that knowing the values for all variables in Model 2 reduces our error in predicting the probability that the department responsible for compliance with the CPTED method is related to effectiveness by 34.7%, compared to 1% in Model 1. The y-intercept tells us that if all variables in Model 2 were equal to 0, the rate for perceived effectiveness would be 1.06. Model 2 shows that when compared with cities whose phase of implementation of CPTED strategies is “in early stages”, those with comprehensive implementation show a .304 higher probability of being rated as very effective. Additionally, the population size of the city also appears to influence how effective zone ordinances/building codes may be as a CPTED method. When compared to cities with populations of under 50,000, cities with populations between 50,000-100,000 show a .214 lower probability in rating the CPTED strategy as very effective. Cities with populations between 100,000-150,000 show a .322 lower probability of rating the CPTED strategy as very effective than cities with populations under 50k.


Table 6: Linear Probability Model for Strategy #2: Effectiveness of Plan/Design Review (N = 99)

 Title

Model 1

Beta

Model 2

Beta


Department Responsible for
Compliance with Strategy
     Proactive Departments

     
Other

Ref Category: Reactive Departments


City's Phase of CPTED
Implementation

     Mature with room for growth

     Comprehensive

Ref Category: In early stages


City Population
     50-100k

     100-150k

     150-200k

     200k and over

Ref Category: Under 50k is reference
category


Form of Government in City
     Weak mayor-council

     Manager-council

Ref Category: Strong mayor-council
is reference category


Y-intercept


R-squared

 


.307*
(.132)
.346*
(.171)






























.125

.031

 




.271

.265




.305*
(.148)
.315
(.181)




.155
(.144)
.421**
(.141)



-.087
(.125)
-.172
(.160)
-.463**
(.179)
-.084
(.181)




.089
(.183)
-.129
(.124)



.054

.192




.269

.241





.156

.426




-.084

-.125

-.256

-.060





.049

-.127



Heteroskedasticity-consistent robust standard errrors used in parentheses
*** p < 0.001, ** p < 0.01, * p < 0.05

In Table 6, the first model shows that proactive departments responsible for compliance with plan/design review exhibit a .307 higher probability than reactive departments of being very effective. Model 1 also shows that “other” departments responsible for compliance with plan/design review have a .346 higher probability of reporting the CPTED method as ‘very effective’. When controls including a city’s phase of CPTED implementation, city population, and form of government in the city are added, proactive departments remain significant while other departments are no longer significant. In Model 2, proactive departments show a .305 higher probability of being very effective than reactive departments. The r-squared value for Model 2 is .192, indicating that knowing the values for all variables in Model 2 reduces our error in predicting the probability that the department responsible for compliance with the CPTED method is related to effectiveness by 19.2%, compared to 3.1% in Model 1. The y-intercept tells us that if all variables in Model 2 were equal to 0, the rate for perceived effectiveness would be .054. Model 2 shows that when compared to cities with phase of CPTED implementation as “In early stages,” cities with comprehensive implementation show a .421 higher probability of being very effective. When compared to cities with populations of under 50,000, cities with populations between 150,000-200,000 show a .463 decrease in the probability of being very effective.


Table 7: Linear Probability Model for Strategy #3: Effectiveness of Managing Public Facilities (N = 76)

 Title

Model 1

Beta

Model 2

Beta


Department Responsible for
Compliance with Strategy
     Proactive Departments

     
Other

Ref Category: Reactive Departments


City's Phase of CPTED
Implementation

     Mature with room for growth

     Comprehensive

Ref Category: In early stages


City Population
     50-100k

     100-150k

     150-200k

     200k and over

Ref Category: Under 50k is reference
category


Form of Government in City
     Weak mayor-council

     Manager-council

Ref Category: Strong mayor-council
is reference category


Y-intercept


R-squared

 


.060
(.160)
-.050
(.186)






























.461

.008

 




.059

-.041




.055
(.162)
-.090
(.179)




.118
(.146)
.459**
(.141)



.076
(.143)
-.004
(.207)
-.105
(.251)
-.208
(.175)




-.115
(.256)
-.074
(.117)



.288

.190




.053

-.074





.114

.455




.073

-.003

-.061

-.135





-.057

-.073



Heteroskedasticity-consistent robust standard errrors used in parentheses
*** p < 0.001, ** p < 0.01, * p < 0.05

Both models in Table 7 do not show significance regarding the effect of the department responsible for enforcing the CPTED method of including a process for managing public facilities on perceived effectiveness. The r-squared value for Model 2 is .190, indicating that knowing the values for all variables in Model 2 reduces our error in predicting the probability that the department responsible for compliance with the CPTED method is related to effectiveness by 19%, compared to less than 1% in Model 1. The y-intercept tells us that if all variables in Model 2 were equal to 0, the rate for perceived effectiveness would be .288. Model 2 shows significance when comparing comprehensive phases of implementation to those considered to be in early stages. For cities with comprehensive implementation, there is a .459 higher probability that the strategy will be rated as very effective when compared to those in early stages.


Table 8: Linear Probability Model for Strategy #4: Effectiveness of Traffic Diversion (N = 85)

 Title

Model 1

Beta

Model 2

Beta


Department Responsible for
Compliance with Strategy
     Proactive Departments

     
Other

Ref Category: Reactive Departments


Community Level of Involvement
     Community involved
           Yes

     Community initiated
           Yes

     Community helped plan
           Yes

     Community assisted
           Yes

     Community informed
           Yes

Ref Category: No


City's Phase of CPTED
Implementation

     Mature with room for growth

     Comprehensive

Ref Category: In early stages


City Population
     50-100k

     100-150k

     150-200k

     200k and over

Ref Category: Under 50k is reference
category


Form of Government in City
     Weak mayor-council

     Manager-council

Ref Category: Strong mayor-council
is reference category


Y-intercept


R-squared

 


-.073
(.122)
-.056
(.140)
















































.406

.005

 




-.074

-.050




-.167
(.140)
-.160
(.140)




.063
(.130)

.019
(.102)

.102
(.114)

-.032
(.143)

.170
(.116)




.277*

(.126)
.254
(.131)



.426**
(.143)
-.010
(.151)
.238
(.189)
.197
(.178)




.350
(.309)
.229
(.116)



-3.87

.280




-.170

-.141





.031


.020


.105


-.029


.177





.280

.250




.375

-.008

.166

.152





.154

.238









Heteroskedasticity-consistent robust standard errrors used in parentheses
*** p < 0.001, ** p < 0.01, * p < 0.05

Neither model in Table 8 shows significance regarding the effect of the department responsible for enforcing the CPTED method of including a process for traffic diversion on perceived effectiveness. The r-squared value for Model 2 is .280, indicating that knowing the values for all the variables in the model reduce our error in predicting the perceived effectiveness of CPTED methods related to traffic diversion by 28%, compared to less than 1% in Model 1. The y-intercept tells us that if all variables in Model 2 were equal to 0, the rate for perceived effectiveness would be -3.87. Model 2 shows significance when comparing the phase “mature with room for growth” of implementation to those considered to be “in early stages”, as well as when city populations of 50,000-100,000 are compared to those under 50,000. For cities in “mature with room for growth” phases of implementation, there is a .277 increased probability that traffic diversion will be considered “very effective” in these cities when compared to cities in early stages of implementation. For cities with populations from 50,000-100,000, there is a .426 increased probability of the strategy being rated as “very effective” when compared to those under 50,000.


Table 9: Linear Probability Model for Strategy #5: Effectiveness of Urban Beautification (N = 139)

 Title

Model 1

Beta

Model 2

Beta


Department Responsible for
Compliance with Strategy
     Proactive Departments

     
Other

Ref Category: Reactive Departments


Community Level of Involvement
     Community involved
           Yes

     Community initiated
           Yes

     Community helped plan
           Yes

     Community assisted
           Yes

     Community informed
           Yes

Ref Category: No


City's Phase of CPTED
Implementation

     Mature with room for growth

     Comprehensive

Ref Category: In early stages


City Population
     50-100k

     100-150k

     150-200k

     200k and over

Ref Category: Under 50k is reference
category


Form of Government in City
     Weak mayor-council

     Manager-council

Ref Category: Strong mayor-council
is reference category


Y-intercept


R-squared

 


.009
(.104)
.045
(.109)
















































.537

.001

 




.009

.042




.065
(.109)
-.037
(.117)




.239
(.143)

.233*
(.107)

-.073
(.097)

.081
(.101)

.017
(.090)




-.176

(.102)
-.085
(.118)



.056
(.109)
.090
(.144)
.202
(.148)
.067
(.136)




.138
(.195)
.084
(.092)



.239

.132




.281

.194





.622


.444


.119


.280


.194





.026

.147




.271

.376

.495

.336





.524

.267









Heteroskedasticity-consistent robust standard errrors used in parentheses
*** p < 0.001, ** p < 0.01, * p < 0.05

Models 1 and 2 in Table 9 do not show significance regarding the department responsible for enforcing the CPTED method of urban beautification and perceived effectiveness. The r-squared value for Model 2 is .132, indicating that knowing the values for all variables in the model reduces our error in predicting the perceived effectiveness of CPTED methods related to urban beautification by 13.2%, compared to less than 1% in Model 1. The y-intercept tells us that if all variables in Model 2 were equal to 0, the rate for perceived effectiveness would be .239. Model 2 shows significance when comparing those who initiated urban beautification versus those who did not: cities with communities who initiated urban beautification show a .233 increased probability that urban beautification will be considered “very effective” when compared with cities in which the communities did not initiate the strategy.

Discussion

The goal of this study was to examine the perceived effectiveness of specific CPTED strategies based on which city departments were responsible for ensuring public compliance with each strategy, as well as to look at the perceived effectiveness of CPTED strategies in communities who are involved with the strategy compared with those who are not. While findings suggest there may be a relationship between type of department responsible for implementing Strategy #2: Plan/Design Review and perceived effectiveness of this strategy (hypothesis 1), the other four strategies did not share this result. This finding may support the need for consulting proactive departments, such as design professionals in public works or city planning offices regarding any type of new urban plan, before involving other more reactive departments in enforcing their implementation (such as police departments or parks and recreation officers). However, more specific research is necessary to explain this result.

This study produced some other findings that do help support the literature. For example, the literature that is available showing evidence that CPTED strategies are effective in reducing crime is limited overall. However, almost all of the strategies (#1-4: zone ordinances/building codes, plan/design review, managing public facilities, and traffic diversion) showed evidence of possible higher perceived effectiveness in cities with comprehensive CPTED implementation when compared to those whose implementation was under consideration or still in early stages. A possible interpretation for these results may be that an important indicator for the effectiveness of these CPTED methods is how far along the city is in implementing these types of strategies (according to beta values). This finding may provide support for the implementation of CPTED methods overall because it indicates that according to the respondents, well-developed CPTED methods do show to be effective in reducing fear of or incidence of crime. Additionally, these results support the work of Minnery and Lim (2005), who determined that high levels of CPTED implementation do correlate with lower levels of crime victimization. Schneider (2005) describes complications associated with the crime-environment connection, and understanding these complications may play a key role in implementing CPTED strategies in ways that achieve higher levels of perceived effectiveness. This finding ultimately provides an opportunity for future research to determine reasoning behind the association of other phases of implementation with higher perceived effectiveness of CPTED strategies.

City population size was also associated with perceived effectiveness for strategies 1, 2, and 4 (zone ordinances/building codes, plan/design review, and traffic diversion), however, the overall relationship seems to vary based on strategy. For strategy #1, CPTED methods corresponding with zone ordinances/building codes may be easier to implement and enforce in the smallest cities when compared to cities with populations between 50,000-150,000. Possible explanations for this include the fact that there may be fewer bureaucratic barriers to implementing these strategies in smaller cities, or that enforcement is overall more manageable when a smaller population is involved. However, more research is needed to examine this relationship because the largest cities (populations of 150,000+) did not show a relationship with perceived effectiveness when compared to cities with populations under 50,000. Strategy #2 showed that the probability of perceived effectiveness decreases in cities with populations 150,000-200,000 in size when compared to cities under 50,000, but no relationships were found in any of the other population sizes. For strategy 4, city populations of 50,000-100,000 were associated with an increased probability of perceived effectiveness when compared to those with populations of under 50,000. These findings for strategies 2 and 4 also support the need for further research to examine a more detailed relationship between city population size and the perceived effectiveness of certain CPTED strategies.

For strategy 5 (urban beautification), cities with communities that initiated the strategy showed higher probabilities of perceived effectiveness of the strategy in reducing crime than communities that did not. This finding aligns with hypothesis 2, and supports some of the existing literature, particularly by Stewart et. al (2019) that indicates resident-led beautification efforts can help change neighborhood narratives from those that highlight degradation to those that highlight community connections. However, this study’s finding is unique in that it specifically relates community-initiated urban beautification to the probability of perceived effectiveness of the CPTED strategy in reducing crime. This differs slightly from Stewart et al. (2019)’s work in that their work focused mainly on the way that building community connections through beautification efforts can help change the reputation of a neighborhood. Further research may be needed to understand why only initiation of the strategy exhibited a relationship with higher perceived effectiveness, while whether the community helped plan/assisted the strategy did not.


Conclusion

Overall, results from this study suggest that certain CPTED strategies show a higher probability of being perceived to be more effective at reducing crime when they are more highly developed. However, the consideration of other phases that were not offered as options on the original data collection instrument may be important to explore. Additionally, city population plays a role in the perceived effectiveness of certain strategies, but more research is needed to more accurately determine this relationship. While the findings of this study support the hypothesis that city departments that help proactively implement CPTED strategies are associated with higher levels of perceived effectiveness when compared with city departments that reactively enforce CPTED strategies for Strategy #2, this relationship may need to be looked at further. For example, future analyses could examine city departments beyond binary categories, and allow for more nuance amongst the different types than “proactive” versus “reactive”. Additionally, a larger sample size may change the results of this analysis. Lastly, future analyses could also look at empirical data of crime statistics, CPTED strategy, and the department responsible for implementation, instead of the perspective of mayors of cities. This may be necessary because “perceived effectiveness” from the perspective of mayors might not align with actual effectiveness. The perspective of the survey data from mayors may also explain the finding that almost every strategy shows higher probability of effectiveness when the strategy is more developed, as mayors may hold some personal stake in CPTED strategies that they helped design or implement. Despite these limitations, this study does contribute to research on urban beautification with the finding that community-initiated CPTED strategies in urban beautification have a higher probability of being perceived as more effective at reducing crime than urban beautification that is not initiated by the community.


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