South Dakota Permit Test 12 Do you currently have car insurance? Insurance is mandatory to drive in South dakota Yes I have insurance. But please show me your best quotes. No, please help me find the best insurance. Question What is the maximum legal length for a single unit vehicle with two or more axles? Answers 25 feet 35 feet 50 feet 60 feet Explanation In North Dakota, a single unit vehicle with two or more axles may be no more than 50 feet long, including its load. South Dakota Permit Test