Since the 1970s, it has become gradually recognised that a reduction of risk leads to compensating changes in behaviour. Straightening roads leads to higher speeds to the extent that chicanes are now often built into residential streets. Seat belt use reduces injuries to car occupants who wear them. However, when first introduced, the legislation applied only to front seat passengers and there was an initial increase in fatalities among rear seat passengers. There was furthermore an increase in the numbers of pedestrians and cyclists injured by belted drivers.