Traffic sign vandalism and demographics of local population: A case study in Utah

Among the different types of traffic sign damage, vandalism is exclusively caused by humans. Traffic sign vandalism is a serious concern, since it can lead to an increase in unsafe driving behaviors. In addition, it results in increased costs to transportation agencies to replace, repair, or maintain the vandalized signs. This paper examines the association between the local population demographics and traffic sign vandalism rates in the State of Utah. To accomplish this goal, sign data of over 97,000 traffic signs across Utah were digitally collected by an equipped vehicle. Sign damage data were obtained from the inspection of daytime digital images taken of each individual sign. Demographic data of Utah's counties, including population density, ethnicity, age, income, education, and gender, were obtained from the U.S. Census. The association between demographic groups and vandalism rates was tested using chi-square and trend tests. The results reveal that the most statistically significant variables comprise median household income, completion of at least an associate degree, and population density. According to the fitted linear regression model, a relationship exists between sign vandalism rate and local population demographic. The findings of this investigation can assist transportation agencies in identifying areas with a higher likelihood of sign vandalism, based on demographic characteristics. Such information can then be used to encourage scheduled sign inspections and to implement various countermeasures to prevent sign vandalism.