Which of the following is NOT a focus of the Environmental Protection Agency concerning trucks?

The focus of the Environmental Protection Agency (EPA) primarily revolves around environmental issues, particularly those related to pollution and emissions. One of the core responsibilities of the EPA is to ensure compliance with emissions standards, which directly pertains to how vehicles, including trucks, should operate to minimize their environmental impact. This includes regulating pollutants released into the air, thus reducing overall air quality concerns.

Vehicle maintenance standards and pollution control measures are also within the EPA’s remit. Maintenance standards ensure vehicles are operating efficiently and not emitting excess pollutants, which aligns with the EPA's mission to protect the environment. Pollution control measures are directly tied to the EPA's overarching goal to reduce harmful pollutants that affect air and water quality.

Driver safety regulations, while crucial for overall road safety, predominantly fall under the purview of the Department of Transportation (DOT) and its associated agencies. The EPA does not typically engage with regulations that dictate how drivers should operate vehicles in terms of safety, as its primary focus is on environmental health rather than driver behavior or safety enforcement. Thus, driver safety regulations do not align with the EPA's main objectives, making it the correct answer in this context.