In doing 60 down rural avenue, the reasoning that "everybody else is doing it" reflects what stage of moral reasoning according to Kohlberg:

In Kohlberg's stages of moral development, the conventional level is characterized by an understanding of societal norms and the importance of conforming to rules and expectations of others. When someone reasons that "everybody else is doing it," they are primarily motivated by the desire to fit in and comply with societal standards, which is a hallmark of conventional morality. This stage involves making judgments based on the approval of others and the acceptance of social rules.

In this scenario, the reasoning reflects a focus on maintaining social order and the regard for others' opinions. Individuals at this stage are often concerned with how their actions are perceived by their peers and society at large, which aligns with the concept that moral decisions are influenced by social norms and expectations. This is distinct from the pre-conventional level, where moral reasoning is typically based on self-interest and the avoidance of punishment, and from the post-conventional level, where individuals may make decisions based on abstract principles and personal ethics.