Road surface quality assessment is one of the most popular tasks around the world. To solve it, there are a large number of systems that work using certain algorithms, including methods of morphological image processing. One of the key criteria for the effectiveness of an algorithm is its time complexity. The following approaches of morphological processing is considered in the article: Dilation, Erosion, Morphological Gradient, Morphological Smoothing. Photos of the road surface of various conditions were used as the material for the study. Based on the proposed methodology of the experiment, it turned out that each of the selected algorithms has a linear time complexity, but the "Dilation" and "Erosion" algorithms have lower absolute time indicators.