Safety, Stress and Work Zone Complexity: A Field Study on Police Officers Performing On-Foot Traffic Control

Workers such as police officers are exposed to many hazardous situations while performing traffic duties, which renders them vulnerable to work accidents. Such a dangerous work context can lead to high stress levels. This is conducive to performance impairment and, consequently, to high-risk situations in which safety, for both workers and road users, may be jeopardized. It then seems important to better understand the stress experienced by traffic workers to ultimately improve road safety. Hence, the current study aims at investigating whether work context could be associated with the stress levels of police officers doing traffic duties on foot. Nineteen police officers in Quebec City and Montreal, Canada, performed traffic duties on several sites (including constructions ones) while their physiological state was measured by a wearable sensor harness. Change in subjective stress was measured every 15 minutes. Characteristics of the environment were also noted for every working site, which permitted to perform hierarchical cluster classifications to assess each site’s complexity. Results show that stress levels were significantly lower for less complex sites. Interestingly, traffic and safety measures-identified through automated computer vision-differ depending on the site complexity and were generally associated with measures of stress. Taken together, these results suggest that the context in which pedestrian workers perform traffic duties, that is the environment and the higher-risk events to which they are exposed, can lead to higher levels of stress. Implications for road safety are discussed in light of these results.