ASPIRE is a quarterly magazine published by PCI in cooperation with the associations of the National Concrete Bridge Council. The editorial content focuses on the latest technology and key issues in the Concrete Bridge Industry.

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P E R S P E C T I V E 10 | ASPIRE Summer 2016 Graffiti removal costs are estimated at over $8 billion per year in the United S t a t e s . I t 's g e n e r a l l y c o n s i d e re d disruptive to public safety and a barrier to economic potential. But when you think of the graffiti, do you think of public art as a deterrent? You will after learning about crime prevention through environmental design (CPTED). Strategies for the Built Environment CPTED is a multi-disciplinary tool aimed at deterring criminal behavior through environmental design. The method provides strategies that influence offenders and was formulated 45 years ago by criminologist Clarence Ray Jeffrey. Central to the theory is the notion of defensible space where people should see and be seen continuously. Strategies may be small scale, such as trimming shrubs that obscure police sight lines, or they may include an entire neighborhood where residences are oriented to ensure occupants can monitor street activity. We'll focus on just two strategies here: natural surveillance and natural territorial reinforcement. Bridge engineers may recognize these terms from project urban design guidelines. These are common language in the lexicon of urban design and refer to natural surveillance and territorial reinforcement, respectively. Natural Surveillance Natural surveillance is often expressed as eyes on the street and relies on the placement of physical features and activities to maximize visibility. This fosters social interaction among legitimate users of the public areas. And when offenders observe this increased scrutiny, crime is deterred because it becomes too risky. Public fear is diminished when offenders c a n b e o b s e r v e d , i d e n t i f i e d , a n d apprehended. Since crime is inversely related to the level of activity on the street, more people in a public setting leads to less crime. Increased pedestrian and bicycle traffic support this effort. And in transportation facilities, vehicular traffic is considered an aide to surveillance. Typical natural surveillance elements in transportation work include trim landscape plantings, transparent noise walls, lighting with good color rendition, and designs that encourage high volumes of citizen use at all times. Natural Territorial Reinforcement Natural territorial reinforcement is another CPTED strategy that promotes the social control of public spaces. Two things happen when citizens acquire a vested interest in high-quality areas. First, an increased sense of ownership encourages local residents to challenge offenders or report them to the police. Second, inappropriate users stand out and are easily identified. People must care about their territory before they're willing to intervene in, or report, crime. Territorial ownership is created by well- maintained premises, which in turn communicates an active presence. And increased use, promoted by high-quality designs, attracts more people and leads to the perception of social control. Typical natural territorial reinforcement strategies in transportation projects include community-based artwork, increased maintenance, and well- defined public areas. Surprisingly, and contrary to traditional law enforcement thinking, research has shown that trees are seen by citizens as creating significantly more attractive and safer spaces. We'll look at a few examples. The urban settings will be familiar to bridge engineers all over the United States. Example: Mount Vernon, Washington State The city of Mount Vernon in western Washington State had an Interstate 5 on-ramp that was being tagged. It so happened that the mayor, Jill Boudreau, had a background in law enforcement. As a community service officer, she worked on the front lines of crime prevention. So when discussions started Bridges and Public Art Crime prevention through environmental design by Paul Kinderman and Matt Rochon, Washington State Department of Transportation Maintenance repair of graffiti on Interstate 5 on ramp in Mount Vernon, Wash., prior to public art (left). Citizens typically consider graffiti disruptive to public safety and economic potential. Public art shows natural territorial reinforcement strategies at the same Interstate 5 on-ramp (right). Photos: City of Mount Vernon. Crime is inversely related to the level of activity on the street.

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