While driving a triple combination, keep the shut-off valves at the rear of the middle trailer in their: Before you start the test, please answer the question below regarding your insurance status. Without insurance you will not be able to drive in Ohio Do you currently have car insurance? Yes I have insurance. Great, you're all set! Click here if you still want to compare rates. No, I need insurance. Click here to compare rates from our insurance partner. Question While driving a triple combination, keep the shut-off valves at the rear of the middle trailer in their: Answers Lowered position. Closed position. Open position. Explanation When operating a double or triple, the shut-off valves at the rear of last trailer should be closed. All other shut-off valves should be open. This questions appears in the following tests: Arizona Double Utah Double