Coals are a great source of energy. In some countries, they used coals to produce electricity and that is the reason why they need lots of coal. Your company is engaged in selling coals and you need to deliver them on time.
Drive your train as fast as you can, but always be careful when driving. Try to consider all the necessary precautions when driving. Make sure that none of the cargo will fell at the back of your train, but if you can;t help it then you can at least minimize it. What is important here is that you deliver the required number of cargo indicated on the screen.