The development of modern cities is impossible without an increase in the number of construction projects implemented. However, in the conditions of limited spaces, local and national legal regulations, and logistic difficulties, their implementation is becoming a growing challenge. Construction supplies can pose a particular problem. Its planning, organization, and implementation have an impact not only on construction and assembly works, but also on the external environment of the construction site, of which traffic is an important element. The aim of the study was to analyze and answer the question of whether there is a connection between the implementation of construction supplies and the occurrence of road traffic hazards in cities on the example of Szczecin. In addition, the article aims to find solutions to reduce the number of road accidents and increase road safety. The conducted research also revealed the weak points of the system of collecting and analyzing data on road accidents. The research covered selected areas in the center of Szczecin, where construction projects have been implemented since 2016 and road accidents have occurred. The reference year is the year preceding the start of construction. The research on selected construction projects meeting the criteria, carried out in the article has shown that their implementation may have an impact on the level of safety in the areas adjacent to the construction site. However, the unequivocal statement of such relationship must be supported by extended research, covering a greater number of projects, additional consideration of the number of deliveries for supply purposes, and the characteristics of vehicles involved in road incidents.