On a highway with four or more lanes, where should slower traffic always be?

Slower traffic should always be in the rightmost lane on a highway with four or more lanes. This is primarily to facilitate smoother and safer traffic flow. The rightmost lane is designated for vehicles moving at lower speeds, allowing faster vehicles to utilize the left lanes without having to navigate around slower vehicles. By keeping slower traffic to the right, it reduces congestion and helps prevent potential collisions caused by sudden lane changes or varying speeds.

In contrast, the leftmost lane is usually reserved for passing. If slower vehicles were to occupy this lane, it could cause delays and unsafe driving conditions as faster vehicles would need to weave through traffic to maintain their speed. Keeping the center lane for general use further enhances traffic efficiency, as this lane allows for a balance of both slower and faster moving vehicles, but the expectation is that slower drivers remain in the rightmost lane to minimize interference with the overall flow of the highway.