When you have your tire blowout on the highway you should keep a firm grip on the steering wheel and then remove your foot from the gas pedal slowly to allow the car to slow down.
While slowing down try to get off the highway and onto the side of the road.
Then slowly press on the brake pedal to bring the vehicle to a complete stop and if you're not completely off the road you can usually continue to steer the vehicle and press the gas pedal to drive the car off the road and get onto the side of the road even with a flat.
Just avoid driving too far on the flat or blown out tire because it can cause damage to the rim and vehicle.
Never slam on the brakes when you have a tire blowout even though that seems like the right thing do to because it can cause someone else to rear end your vehicle or cause your vehicle to go out of control.