around 27%. Road traffic safety Schleinitz et al. (2014) concluded that e-bike users in Germany were no more likely than conventional cyclists to be involved in "safety-critical situations". However, Dozza et al. (2015) concluded (from an analysis of Swedish cyclists) that e-bikers may be involved in more critical incidents but with "lower severity". Additionally, e-bikers were less likely to have dangerous interactions with motorized vehicles. Environmental effects E-bikes are zero-emissions vehicles, as they emit no combustion by-products, but the environmental effects of electricity generation and power distribution and of manufacturing and recycling batteries must be accounted for. E-bikes emit similar pollutants per kilometer as buses, with emission rates several times lower than motorcycles and cars. Even with these issues considered, e-bikes have a significantly lower environmental impact than cars, and are generally seen as environmentally desirable in an urban environment. A 2018 study in England found that e-bikes, if used to replace car travel, have the capability to "cut car carbon dioxide (CO2) emissions in England by up to 50% (about 30 million tonnes per year)". It has been suggested that the greatest opportunities are in rural and sub-urban settings: city dwellers already have many low-carbon travel options, so the greatest impact would be on encouraging use outside urban areas. There may also be scope for e-bikes to help people who are most affected by rising transport costs. The environmental effects involved in recharging the batteries can of course be reduced. The small size of the battery pack on an e-bike, relative to the larger pack used in an electric car, makes them very good candidates for charging via solar power or other renewable energy resources. Sanyo capitalized on this benefit when it set up "solar parking lots", in which e-bike riders can charge their vehicles while parked under photovoltaic panels. The environmental credentials of e-bikes, and electric / human powered hybrids generally, have led some municipal authorities to use them, such as Little Rock, Arkansas, with their Wavecrest electric power-assisted bicycles or Cloverdale, California police with Zap e-bikes. China's e-bike manufacturers, such as Xinri, are now partnering with universities in a bid to improve their technology in line with international environmental standards, backed by the Chinese government who is keen to improve the export potential of the Chinese manufactured e-bikes. Both land management regulators and mountain bike trail access advocates have argued for bans of electric bicycles on outdoor