Question Unless otherwise posted, the minimum speed limit on freeways is: Answers 45 mph. 55 mph. 70 mph. 85 mph. Explanation Unless otherwise posted, the minimum speed limit on freeways is 55 mph. If a different speed limit is posted, you should follow that speed limit. Pass your DMV Written Test with flying colors Take me to the cheat sheet Michigan This questions appears in the following tests: Michigan Practice Test 46 Michigan Practice Test 28