What side do you pass a vehicle while on a expressway?

When passing a vehicle on an expressway, you should always pass on the left side. This is because the left lane is typically designated for faster-moving traffic and overtaking slower vehicles. Ensure that it is safe to change lanes by checking mirrors and blind spots, and signal your intentions before moving over. After passing, return to the right lane when it is safe and you can see the vehicle in your rearview mirror.