The article discusses how different strategies for enforcing traffic laws in high-occupancy-vehicle (HOV) lanes on California freeways have faced challenges. These challenges include limited personnel, confusion, and physical constraints. A two-year study was conducted to evaluate the impact of enforcement options, engineering features, and educational programs on violation rates. The study found that different enforcement activities and design features can affect violation rates, freeway performance, and public attitudes. By measuring violation rates, enforcement levels, and accident levels, the study recommended future enforcement programs for California HOV lanes.