Evaluating the effects of speed reduce for shipping costs and CO2 emission

•Optimum speed reductions in shipping could significantly reduce costs as well as CO2 emissions.•Optimum ship speed management could encourage ship operators to voluntarily implement measures to reduce CO2 emissions.•A modified model for examining efforts of speed reduction. Global greenhouse gas emissions have driven up carbon dioxide levels beyond 400 parts per million, thereby increasing the rate of global warming. This paper conducted a thorough assessment of available operating strategies to identify the approach to speed reduction that is best able to minimize costs and reduce the impact of shipping on the environment. Our results indicate that optimum speed reduction is a dynamic process depending largely on charter rates and fuel prices. The significant cost advantages afforded by this approach could improve the competitiveness of ship operators.