What is the first thing you should do when a low air pressure warning comes on?

Answer: B — Stop and safely park as soon as possible.

When a low air pressure warning comes on, the first action you should take is to stop and safely park as soon as possible. This is crucial because low air pressure in a vehicle with air brakes can lead to brake failure, significantly increasing the risk of an accident. Continuing to drive could compromise your ability to stop the vehicle safely, posing a danger to both the driver and others on the road. While checking the air pressure gauge is important for diagnosing the issue, doing so after safely parking allows you to assess the situation without the immediate risk of losing braking power. Engaging the emergency brake immediately may not be the safest response, as it could lead to a sudden stop that could potentially cause an accident in active traffic. Therefore, the best practice emphasizes prioritizing safety by stopping the vehicle in a controlled manner before addressing the air pressure issue.