Question Unless otherwise posted, the maximum speed limit on a state road is: Answers 70 mph. 55 mph. 40 mph. Explanation When driving on state roads, the speed limit is 55 miles per hour. If a different speed limit is posted, follow the posted speed limit. Pass your DMV Written Test with flying colors Take me to the cheat sheet Mississippi This questions appears in the following tests: Mississippi Practice Test 20 Mississippi Practice Test 13