Application of traffic models nowadays has become a common practice, and is preferable before any implementation of new traffic solutions on the field, and subsequent testing. The construction of additional transport infrastructure or any expensive infrastructure intervention, without prior simulation of a future transport solution can be considered and archaic and inefficient approach. Taking into account the constant increase of road traffic demands, the impossibility of predicting the optimal use of current and future capacities. With the help of intelligent transport systems, the values of parameters from the terrain are collected, which are then used to calibrate the traffic model. The development of computer technologies and applications has enabled the use of complex algorithms while calibrating traffic simulation models. Genetic algorithm is used in this master’s thesis to calibrate the traffic flow of each individual approach within the intersection, and for this, PTV VISSIM simulation program was used. Within VISSIM the simulation was performed, associated with Python programming language via COM connection. The calibration was able to optimize the traffic flow in one hour interval, depending on how different the input values are from the output traffic flows of the selected isolated intersection, which should be approximately the same. When calibrating the model in a 24-hour cycle, the calibration of the simulation depended on the ratio of vehicle input and output values, for each individual hour. Initiated machine learning using a genetic algorithm lasted for a couple of hours, for an one hour simulation, to four days for an 24-hour simulation. Within a period of 24 hours, any higher ratio of vehicle numbers per hour, for each approach can result in a unacceptable values for the fitness function, which ultimately generated poorer solutions. With a smaller volume of traffic flow per approach and shorter cycles, such as one hour, the genetic algorithm module generates optimal solutions, compared to the period for the the whole day, where the coefficients for every approach deviated beyond acceptable limits.