What is the maximum legal length for a single unit vehicle with two or more axles? Do you currently have motorcycle insurance? Insurance is mandatory to drive in Ohio 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 20 feet 30 feet 40 feet 50 feet Explanation In North Dakota, a single unit vehicle with two or more axles, including its load, may be no more than 50 feet long.