Co-benefit evaluation for urban public transportation sector – a case of Shenyang, China

• Careful selection of bus and taxi types can bring co-benefits.
• Electricity and hybrid vehicles have higher embodies emissions.
• CNG bus has the best overall environmental performance with the least costs.
• Diesel car is the best choice for taxi fleet.
• An integrated effort is needed in order to reach co-benefit in public transportation sector.

Buses and taxies are the most widely used vehicles for urban public transportation in developing countries. They contribute significantly to the emissions of greenhouse gas and air pollutants. Policy makers consider the introduction of new emissions standard vehicles and alternative fuel vehicles in bus and taxi fleets as an attractive measure for reducing the emissions of greenhouse gas and air pollutants. It is important to understand the environmental benefits and economic challenges involved in fleet conversion. However, few studies have been conducted, especially in developing countries. This study analyzes the cost effectiveness and environmental benefits of various vehicles by employing a case study in Shenyang, China. The results showed that CNG bus has the best overall economic and environmental performances, while diesel car is one possible choice for taxi selection when considering the current technology level. Although direct emissions are lower for both hybrid and electricity vehicles, embodied emissions are higher, plus higher costs, making them not suitable as public transportation tools, at least for the current stage. In order to further improve co-benefits in public transportation sector, an integrated effort is needed, including the gradual phase-out of inefficient vehicles, green vehicle purchase, infrastructure improvement and capacity-building initiatives.