Question Unless otherwise posted, the speed limit on a four-lane divided highway is: Answers 35 mph. 55 mph. 70 mph. 80 mph. Explanation When driving on a four-lane divided highway, the speed limit is 70 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 Oklahoma This questions appears in the following tests: Oklahoma Practice Test 14 Oklahoma Practice Test 5