A safety report indicates that, on average, traffic fatalities decline by about 7 percent in those areas in which strict laws requiring drivers and passengers to wear seat belts have been passed
In a certain city, seat belt laws have been in effect for two years, but the city' s public safety records show that the number of traffic deaths per year has remained the same
Two years ago speed limits in the city were increased by as much as 15 kph (9 mph).