Downshift to low range (labeled as 1) in case of automatic transmission and low gear in manual transmission.
Pump the brake pedal fast and hard to build up brake fluid pressure. You will know in three to four pumps if the brakes will work. Do not pump antilock brakes. (In case of ABS, the driver has to press down hard on the brake pedal and hold it. In an emergency situation, ABS pumps the brakes for the driver and pumps the brakes at a much faster rate than the driver ever could.)
Apply the parking brake, but be ready to release it if the car begins to skid.
You can still steer and swerve. Find an escape route—a safe exit from the highway. If you must, steer into bushes or something soft.
Sound your horn and flash your lights to warn other drivers.
When you no longer need to change direction, turn off the ignition.