What is the first thing to do when you see an emergency vehicle with flashing lights?

When you see an emergency vehicle with flashing lights, the first thing you should do is slow down and prepare to stop. This action is crucial for the safety of both the emergency responders and other drivers on the road. By slowing down, you give yourself time to assess the situation, ensuring that you are ready to react appropriately, whether it involves stopping or safely maneuvering around the emergency vehicle.

In many jurisdictions, there are laws requiring drivers to yield the right of way to emergency vehicles. Failing to reduce your speed can impede the emergency vehicle's response time and may put both the emergency personnel and other road users in danger. Preparing to stop also allows you to gauge whether you need to pull over to the side of the road if safe to do so, facilitating the passage of the emergency vehicle.

Other options, such as maintaining speed or honking the horn, do not prioritize safety and can exacerbate the situation rather than help it. Similarly, while changing lanes away from the emergency vehicle is often a good practice once you've slowed down and assessed the situation, it is not the immediate first step. Therefore, the correct answer emphasizes the importance of slowing down and preparing for any necessary action.