How does Pennsylvania aim to reduce vehicle emissions?

Pennsylvania aims to reduce vehicle emissions through the implementation of stringent testing requirements. This approach involves regular emissions testing for vehicles to ensure that they meet established environmental standards. By enforcing these testing protocols, the state can identify and address high-emission vehicles, requiring repairs or adjustments to help lower emissions. These regulations are part of the broader strategy to improve air quality and reduce environmental impact from transportation sources.

While the other options may have varying economic impacts or address transportation systems, they do not directly contribute to the specific goal of reducing vehicle emissions. For instance, lowering registration fees or increasing fuel prices would not necessarily lead to a decrease in emissions. Encouraging more driving goes against the goal of decreasing the overall emissions from vehicles. Thus, implementing stringent testing requirements is the most effective method for managing and reducing emissions from vehicles in Pennsylvania.