When being passed on an expressway, what should a driver do?

When being passed on an expressway, it is advisable to keep a steady speed. This action helps to maintain stability and predictability on the road, allowing the passing driver to overtake without unnecessary complications. When a driver accelerates or changes lanes abruptly, it can create confusion and increase the risk of collisions, as it disrupts the flow of traffic. Similarly, decreasing speed could also lead to unsafe situations as it doesn't facilitate a smooth passing maneuver. By maintaining a consistent speed, the driver helps ensure that the passing vehicle can safely complete their maneuver without encountering unexpected changes in speed or direction.