Except as otherwise provided by statute or by any commission, department or other body authorized by law to impose penalties for violations of rules, regulations and orders governing the use and operation of vehicles, any person convicted of violating any of the provisions of the foregoing rules and regulations shall be punishable by a fine of $25 for each offense; the provisions of this section shall not supersede any penalties established by the RMV, MGL c. 90 or any other section which has a fine, violation or penalty already established.