Electric two-wheelers in China: Analysis of environmental, safety, and mobility impacts.

摘要

Chinese cities have a long legacy of bicycle use due to relatively low incomes, dense urban development, and short trip lengths. Because of tremendous economic growth, increased motorization, and spatial expansion of cities, trips are becoming longer and more difficult to make by bicycle. As a result, electric powered two-wheelers have risen in popularity over the past five years, with sales exceeding 16 million in 2006. Recently, policy makers have enacted bans on electric two-wheeler use, citing a poor safety record, a large contribution to congestion, and poor environmental performance. This study quantifies many of the safety and environmental impacts of electric two-wheelers and balances the negative externalities by quantifying benefits to users in terms of increased mobility and access to opportunities.; Touted by some as environmentally friendly vehicles, electric two-wheelers are capable of traveling 40-50 kilometers on a single charge and emit zero tailpipe emissions. However, they do have significant environmental impacts because they use lead acid batteries that are recharged with electricity that is predominantly generated from coal power plants, but they also have significant mobility benefits that are seldom considered. This research investigates the tremendous growth of electric two-wheelers in China and compares their environmental and safety impacts to those of alternative modes of transportation; such as traditional bicycles, public transportation, or personal cars. This research also analyzes the benefits of electric two-wheelers in terms of increased mobility and accessibility to opportunities due to their increased speed and range.; Electric two-wheelers tend to be more energy efficient and produce less air pollution per kilometer traveled than many other modes. Also, to the extent that they displace car trips, they improve the safety of the transportation system in Chinese cities. Electric two-wheelers provide much higher mobility and access to opportunities than all other low cost modes.; The impacts of electric two-wheelers on the transportation system are dependent upon local characteristics of the transportation system. Considering alternative transportation modes in two case studies (Shanghai and Kunming), banning electric two wheelers will result in higher net energy use and greenhouse gas emissions. Moreover, the public health impacts from traditional air pollutants and road safety would likely be worse in a situation where electric two-wheelers are banned. The mobility and accessibility to the city will also deteriorate significantly for users of electric two-wheelers. However, allowing electric two-wheelers in a city results in significant increases in lead pollution over the lifecycle, compared to alternative modes. This research shows that while electric two-wheelers do have some problems that need to be addressed (namely excessive lead acid battery pollution); they provide large benefits and can be a successful strategy toward a sustainable transportation future.