Final answer:
Remain calm, gradually reduce speed, check for traffic, and carefully steer back onto the road when it is safe to do so, using indicators and ensuring not to interfere with the flow of traffic.
Step-by-step explanation:
If your vehicle runs off the roadway, the most important thing is to remain calm and follow a safe procedure to return to the road. Firstly, do not overreact or steer sharply, as this could cause you to lose control of the vehicle. Instead, gradually reduce your speed and check for traffic. Look for a safe place where you can return to the roadway without causing a hazard to yourself or other drivers. Use your mirrors and turn signals to indicate your intention to re-enter the lane. Carefully steer back onto the road when safe, ensuring that you do not interfere with the traffic flow. Remember, sudden movements can make the situation more dangerous, so it's crucial to stay focused and make smooth, controlled actions.