During what circumstances is it legal to use the left lane on a multi-lane highway?

Using the left lane on a multi-lane highway is primarily designated for passing slower vehicles. This rule is essential for maintaining smooth traffic flow and ensuring safety on the road. When you utilize the left lane, it allows faster-moving vehicles to overtake others that are driving at slower speeds in the right lane. This ensures that congestion is minimized and that all drivers can travel at their preferred speed.

The focus on the left lane for passing is particularly important because it helps avoid confusion and erratic lane changes that can lead to accidents. Drivers who stay in the left lane unnecessarily can impede the progress of others, which defeats the purpose of having multiple lanes and can lead to frustration and unsafe driving conditions. Therefore, proper use of lanes not only aligns with legal traffic rules but also promotes overall road safety for everyone.