Santos, OsvaldoRibeiro, Fernando ReinaldoMetrôlho, J.C.M.M.Dionísio, Rogério Pais2024-03-042024-03-042024SANTOS, O. [et al.] (2024) - Using smart traffic lights to reduce CO2 emissions and improve traffic flow at intersections: simulation of an intersection in a small Portuguese city. Applied System Innovation. 7:(1):3. DOI: https://doi.org/10.3390/asi7010003http://hdl.handle.net/10400.11/8907Reducing CO2 emissions is currently a key policy in most developed countries. In this article, we evaluate whether smart traffic lights can have a relevant role in reducing CO2 emissions in small cities, considering their specific traffic profiles. The research method is a quantitative modelling approach tested by computational simulation. We propose a novel microscopic traffic simulation framework, designed to simulate realistic vehicle kinematics and driver behaviour, and accurately estimate CO2 emissions. We also propose and evaluate a routing algorithm for smart traffic lights, specially designed to optimize CO2 emissions at intersections. The simulations reveal that deploying smart traffic lights at a single intersection can reduce CO2 emissions by 32% to 40% in the vicinity of the intersection, depending on the traffic density. The simulations show other advantages for drivers: an increase in average speed of 60% to 101% and a reduction in waiting time of 53% to 95%. These findings can be useful for city-level decision makers who wish to adopt smart technologies to improve traffic flows and reduce CO2 emissions. This work also demonstrates that the simulator can play an important role as a tool to study the impact of smart traffic lights and foster the improvement in smart routing algorithms to reduce CO2 emissions.engCO2 emissionsSmart traffic lightsSmart intersectionsCO2 estimationRoad traffic simulationVehicle specific powerConsumption estimationIntelligent traffic lightsjournal article10.3390/asi7010003