This study will implement and evaluate a multi-component environmental intervention to prevent excess weight gain among 1200 bus drivers working in four garages in a major metropolitan area. Four garages will be randomized to the intervention or control group for a two-year period. The environmental interventions are based on a social ecological framework and target four worksite environmental areas: 1) food availability and incentives; 2) physical activity opportunities and incentives; 3) the social environment; and 4) media/promotion related to health food choices, physical activity, and body weight.