Abbreviation of "Killed or Seriously Injured".

This term is frequently used in traffic statistics, although it has limitations when comparing different countries as it does not take factors such as modal share into account. This can have the effect of making modes of transport which are unpopular in a country appear safer than they are. It also does not account for differences in demographics; in a country with a hostile cycling environment, the people willing to cycle will differ from those who cycle in a country with an inviting cycling environment.