Am not a truck driver but I found myself in the driving seat but I didn't know the controls. Approaching a barrier I didn't know where the break pad was. I wasn't in full control and fearing to hit the barrier I woke up!
This dream may represent a feeling of being out of control in a situation that is important to you. You may feel like you have been put in a position that you are not fully prepared for, and are afraid of not being able to handle it. It may be helpful for you to take some time to identify what areas of your life you feel uncertain about, and take deliberate steps to educate yourself, build your confidence, and regain control. This dream could serve as a reminder for you to be proactive in taking charge of your life and pursuing the things that are important to you.