The article proposes a computer system for determining car speed based on a Raspberry Pi 4 single-board computer, which uses the Raspberry Pi camera module and the OpenCV image recognition library. For the operation of the computer system, it is enough to use any camera with a matrix resolution of 0.3 megapixels. Using the small resolution of the matrix increases the computing power of the system. During image processing, the two-dimensional Gaussian function was used to calculate the transformation of each pixel in the image, and Otsu's method of binarization, which is based on clustering, automatically calculates the thresholded image. This system allows one to detect a car and determine its speed in a predetermined rectangular area. Unlike existing systems, the operation of the proposed system is not affected by objects in the general field of the camera view, because only objects in the defined area are analyzed.