In large cities, the number of vehicles in daily circulation is increasing significantly. In parallel with the
evolution of urban structures, the road infrastructure is struggling to keep up with this flow of vehicles. Such
a situation could become more and more cumbersome until it leads to unmanageable conditions that could
reach complete congestion of the crossroads. Thus, due to its negative impact on the daily lives of vehicle
users, many studies have addressed this problem, but the issue is still relevant today and is attracting more
attention from researchers, especially with the emerging paradigm of smart cities. To this end, different
approaches have been developed to overcome the waiting time hindrance at road junctions and avoid the
costly and stressful situation of trafic congestion. In this context, the significant studies conducted so far are
analyzed in this paper in order to synthesize the different approaches used. The objective is to highlight the
important elements of a successful solution for trafic signal planning at intersections. Such a solution must
be consistent with the requirements and environment of the smart city concept. Thus, different solutions to
the problem posed, in the form of Smart Trafic Light Management Systems (STLMS), have been based on
models applied to one or more intersections and using mathematical optimization techniques, wireless sensor
networks, or both. Nevertheless, none of the proposed methods has addressed the problem as a whole, i.e.,
the coordination and cooperation of STLMS at all intersections of a smart city and the integration of the
overall system into the IoT environment.