What must a driver traveling slower than normal traffic speed do when approaching an upgrade with a passing lane?

When a driver is traveling slower than the normal speed of traffic and approaches an upgrade that has a passing lane, the correct action is to use the right lane. This is important because the right lane is generally intended for slower-moving vehicles, allowing faster vehicles to pass safely in the left lane.

Using the right lane helps to maintain the flow of traffic and ensures that faster vehicles can overtake without delays. It is essential for safety and efficiency on the roadway. Keeping to the right is especially critical when there is a substantial speed difference, as it minimizes the risk of collisions and congestion caused by slower vehicles occupying the left lane, which is designated for passing.

Options that suggest using the left lane or maintaining speed in the center lane fail to recognize the importance of allowing faster-moving traffic to pass. Stopping until traffic clears could lead to unnecessary hazards and impede overall traffic flow. Thus, utilizing the right lane when moving slower than traffic is the most responsible choice in this scenario.