The speed limit is a set of suggestions that are based primarily on community safety. Driving represents the movement through life, and speeding suggests that you are moving fast and taking risks in order to do so. Consider the sensation of the dream to inform your interpretation.
If you feel euphoric, you may desire to increase the exhilaration in your life.
If the speed frightens you, the speed of things in your life is overwhelming.
If you are being pulled over for speeding, you are paying the consequences for risky behavior.
[1]1. Compelled to finish something quickly.
2. Feeling a threat.
3. Moving too fast in a situation or relationship.
[2]A literal warning to slow down
[3]