The researcher observing bike riders at an intersection is collecting data on:

The researcher observing bike riders at an intersection is collecting data on public behavior because the bike riders are engaging in activities that are visible and open to anyone in the vicinity. Public behavior refers to actions or conduct that can be witnessed by others in public spaces without any expectation of privacy. In this scenario, the intersection is a public area where individuals are aware that their behaviors can be observed and recorded by others, including researchers.

Private behavior would involve actions taken in a setting where individuals have a reasonable expectation of privacy, such as in their homes or secluded environments, which is not the case here. Restricted behavior suggests limitations on who can observe or participate, which does not apply in this open public setting. Confidential behavior relates to the handling and protection of sensitive information, typically associated with the privacy of subjects rather than the visibility of their actions. Thus, the best fit for this scenario is public behavior, as the researcher is recording actions that occur in an accessible and observable environment.