The aim of the study was to assess the content of Ca, Mg, Na and K in the road dust collected in Białystok from various environments (roads with high traffic intensity, housing estate roads, roads located near parks and green areas), in order to determine the impact of the road transport on the spatial differentiation of the content of the tested components in street dust and identify their main sources. In total, the samples from 69 points were analyzed, which were taken in spring 2018 (late April and May) during the dry weather. The content of Ca, Mg, Na and K was determined by means of atomic absorption spectrometry (AAS). The average contents of the tested elements in the dust from all measuring points were in the following order: Ca (23.53%) > Mg (2.38) > Na (1.16) > K (0.25). This shows that Ca is the most numerous element in the tested dusts. Studies have not shown a significant impact of vehicle traffic, in particular the so-called non-exhaust sources related to this traffic on the content of main elements in the Białystok road dusts. The analyses have indicated that the main source of Ca and Mg in the Białystok road dust constitute the structural elements of roads, bridges and structures, in which building cement and its derivatives are the main component.