Energy use in the transportation sector (i.e., gasoline, diesel, or liquefied petroleum gas, with most vehicles being operated with gasoline or diesel), has made a major contribution to the deterioration of urban air quality and is responsible for a significant amount of greenhouse gas (GHG) emissions, which include: carbon dioxide (CO2), methane (CH4), nitrous oxide (N2O), chlorofluorocarbons (CFCs), and sulfur hexaflouride (SF6).
On the global scale, transport activity for both passengers and freight is growing rapidly and is expected to double by 2050 (IEA, 2009). Internationally, increased attention has been directed towards green transportation as governments are faced with the onset of climate change. The environmental impacts of transportation systems are considerable, accounting for 20–25% of the world’s energy consumption yearly (Zhou et al., 2010). Energy use in the transportation sector (i.e., gasoline, diesel, or liquefied petroleum gas, with most vehicles being operated with gasoline or diesel), has made a major contribution to the deterioration of urban air quality and is responsible for a significant amount of greenhouse gas (GHG) emissions, which include: carbon dioxide (CO2), methane (CH4), nitrous oxide (N2O), chlorofluorocarbons (CFCs), and sulfur hexaflouride (SF6).