Question This sign means: Answers Minimum speed limit is 40 mph. No turn on red. Fines double in work zone. Added lane. Explanation Regulation signs regulate traffic speed and movement, displaying rules which drivers must obey. This sign indicates a minimum legal driving speed and drivers should not drive below the speed posted. Pass your DMV Written Test with flying colors Take me to the cheat sheet Indiana This questions appears in the following tests: Indiana Practice Test 7 Indiana Practice Test 34