In this paper, the well-known Ford-Fulkerson algorithm in graph theory is used to determine the maximum flow in a road traffic network. Road traffic congestion is a major urban transport problem that occurs when the volume of traffic exceeds the capacity of existing road facilities. The manifestation of traffic congestion is due to the ownership of a high number of vehicles at the expense of road traffic infrastructure and the high growth of the urban population. Only one road connects the city center of Kinshasa, which concentrates the main activities of the inhabitants, to the international airport of Ndjili. Whether you are a pedestrian, a car driver or a public transport user, you cannot escape the traffic jams that refuse to leave Kinshasa. Even motorbike taxis cannot escape. Yet the grade separations built on Lumumba Boulevard in Debonhomme, at the Marché de la Liberté and at Pascal are all open to traffic. Built to facilitate the flow of traffic between the city center (Gombe) and N'djili International Airport, these elephantine structures serve little purpose. In this study, the identification of the maximum flow and bottleneck path along the Lumumba Boulevard between Debonhomme and Ndjili International Airport in the Tshangu district of Kinshasa was carried out. All possible routes from the different sources to the different wells were established. It emerged from this study that the optimal solutions would be the construction of secondary roads and improvement of the road facilities to minimize the problem of traffic congestion.