The march of the electric bike began in China around 1998. A bike like that costs between 150 and 200 dollars there, making it affordable for large numbers of people. In Hangzhou, a city also known to tourists, with well over six million inhabitants, accident statistics have been kept over the period 2004-2008. These demonstrate that although the overall number of accidents and fatalities has decreased, accidents with electric bikes have strongly increased. The number of accidents with injuries per 100,000 electric bikes rose by 2.7 (from 1.5 to 3.9). (Of the 397 fatalities in that period almost 58% was younger than 30). Over the same period the number of fatalities with regular bikes fell from 232 to 101, although these data are not entirely reliable as registration data are imperfect. This is in part due to the fact that currently 33,000 free rental bikes are available in the town.
The Chinese reporting on the study in the article 'Electric-bicycle-related injury: a rising traffic injury burden in China' in the magazine Injury Prevention feel the data are disturbing and press for measures such as improving infrastructure and an obligatory helmet. Incidentally, in a number of cities, like Beijing, electric bikes are officially not allowed due to environmental problems with the batteries. However this appears to be disregarded on a large scale.
Although the study certainly serves as a warning, it is not possible to translate the data one-on-one to the Dutch situation, for instance. Therefore the data would have to be correlated to the use of electric bikes, which appears to be lacking in Hangzhou. It is however well-known that the number of electric bikes has by now grown from 1.4 million to well over 6 million. In addition there appear to be many heavy (over 40 kilos) electric bikes in China capable of reaching speeds of up to 60 kilometres an hour.