On the one hand, there are many possible solutions that the authorities can take to reduce the traffic jam and pollution. First, there are more and more sustainable energy sources such as solar power, wind power, and hydropower that can be utilized to run vehicles and factory, and as a result, the emission of greenhouse gases or other harmful gases like carbon monoxide and CFC will be reduced. For example, there are many countries using solar panels to run public vehicles or to produce electricity for household usages. This not only saves money on the electricity bill, but also encourages people to travel around with eco-friendly and cheap vehicles such as train or bus.