If your vehicle catches fire while you are driving, you should

2.21.3 – Fire Fighting
Knowing how to fight fires is important. Drivers who didn’t know what to do have made fires worse. Know how the fire extinguisher works. Study the instructions printed on the extinguisher before you need it. Here are some procedures to follow in case of fire.
Pull Off the Road. The first step is to get the vehicle off the road and stop. In doing so: Park in an open area, away from buildings, trees, brush, other vehicles, or anything that might catch fire.
Don't pull into a service station! Notify emergency services of your problem and your location.
Keep the Fire from Spreading. Before trying to put out the fire, make sure that it doesn't spread any further.
With an engine fire, turn off the engine as soon as you can. Don't open the hood if you can avoid it. Shoot foam through louvers, radiator, or from the vehicle’s underside.
For a cargo fire in a van or box trailer, keep the doors shut, especially if your cargo contains hazardous materials. Opening the van doors will supply the fire with oxygen and can cause it to burn very fast.
Extinguish the Fire. Here are some rules to follow in putting out a fire:
When using the extinguisher, stay as far away from the fire as possible.
Aim at the source or base of the fire, not up in the flames.
Use the Right Fire Extinguisher
[Commercial Driver’s License Manual]