How do switch off driving mode on samsung galaxy s3?

Just bring down the notification bar, and scroll the toggles (Wi-fi, Bluetooth) to the right to find the little steering wheel icon, and click on it.

If you dont find it, click the icon on the top right that looks like 3 squares, and it'll bring up all of the toggle settings. From there, find the steering wheel icon, that will turn driving mode off, and on.