In a dual-lane expressway (per direction), what is the left lane primarily used for?

In a dual-lane expressway, the left lane is primarily designated as the passing lane for motor vehicles. This lane is intended for overtaking slower-moving vehicles, allowing faster traffic to flow efficiently. When drivers want to pass another vehicle that is traveling in the right lane, they should use the left lane for this purpose, which promotes smooth traffic movement and helps prevent congestion.

Using the left lane specifically for passing ensures that slower and heavier vehicles, which might create delays if they occupy that lane, stay on the right. This not only enhances safety by reducing the need for abrupt lane changes but also aligns with traffic regulations that often require vehicles to keep right except when passing. By adhering to this rule, all drivers can contribute to a more organized and safer driving environment on high-speed roads.