Do you currently have car insurance? Insurance is mandatory to drive in California Yes I have insurance. But please show me your best quotes. No, please help me find the best insurance. Question Unless otherwise posted, the speed limit on primary and secondary state and federal highways is: Answers 55 mph. 45 mph. 65 mph. Explanation Unless otherwise posted, the speed limit on primary and secondary state and federal highways in Tennessee is 55 miles per hour. Take a FREE Practice Test Now This questions appears in the following tests: Tennessee Practice Test