What is the primary function of a buffer in traffic control?

The primary function of a buffer in traffic control is to separate different traffic types. Buffers serve as a physical or visual barrier that delineates different lanes of traffic or separates various modes of transportation, such as bicycles and cars. This separation helps to reduce conflicts between different types of traffic and improves safety for all users by clearly defining their paths.

For instance, in urban environments, buffers can be utilized to separate vehicle lanes from bicycle lanes, ensuring that cyclists have a designated space free from vehicle interference. This segregation can lead to improved traffic flow and safety, as it minimizes the risk of accidents.

The other choices focus on aspects that are not directly related to the primary purpose of a buffer. Enhancing flow capacity, managing speed, and improving environmental conditions may be goals of the overall traffic system design, but they do not accurately describe the fundamental role of a buffer within traffic control. Buffers are specifically about separation, making them crucial for effective traffic management and safety.