More about Trucks & Trailers you can read on Trucks & Trailers official website.
|Throttle||Up Arrow, W|
|Brake/Reverse||Down Arrow, S|
|Steering Left||Left Arrow, A|
|Steering Right||Right Arrow, D|
|Shift Up (manual)||Left Shift or Right Shift|
|Shift Down (manual)||Left Ctrl or Right Ctrl|
|Show / Hide Info Screen||F1|
|Show/Hide Wing Mirrors||F2|
|Show / Hide On-Screen Dashboard||F3|
|Show / Hide Navigation Map||M|
|Free Rotate Camera||1|
|Look Left||Mouse Left or Numpad /|
|Look Right||Mouse Right or NumPad *|
|Rotate Camera||Left Alt|
Note: Some of the above keyboard actions (such as Steering Left or Steering Right) may be overridden by additional controllers (joystick, gamepad, wheel etc.) and may no longer work.
If you select a game controller other than keyboard, you are automatically switched to the controller's settings. You should setup the controlling device properly right away, otherwise it will not work in the game. You can switch between the controller and key settings any time by pressing the button in the lower left corner of the controls settings screen. Caution, certain keyboard controls (especially related to steering) may become disabled as they may be overridden by the additional controller.