General Meanings:

When you dream of an accelerator, it signifies the achievement that you will have, through your endeavor. This dream could also tell you to move on things a little bit slower, as there is no need to rush and you will reach the task you wanted to achieve for a long time.

If you see the accelerator broken or fractured, it means that you do not have the ability to control  some parts of your life, what you have to do is, to pull yourself together and take that control into your hands to get the results you wanted to get. Do not rush when you will make the important decisions.