This paper presents the results of the 2002 Moving Traffic Study of the National Occupant Protection Use Survey (NOPUS) and documents the study's sample design, estimation, and data collection procedures. The main findings on belt and helmet use in 2002 are: Belt use reached 75% in 2002; Primary states reached a milestone of 80% belt use; Belt use increased in the Northeast and in vans and sport utility vehicles; and Helmet use dropped sharply, to 58% from 71% two years ago. This paper also documents changes to the Moving Traffic Study in 2002. A new data collection protocol was begun for interstates, in which use was observed from moving vehicles on the interstate, rather than from exit ramps.This should eliminate the bias incurred from using the ramps as proxy observation sites. Also, variances of changes from one time period to another were estimated directly in 2002, which should improve assessments of significance. It is planned to apply this variance procedure to all change estimates and significance tests in the near future.
Abstract