I have just had 2 DPS offices tell me (including the one in Livingston) that both chapter 6 (concerning air brakes) and chapter 14 are required. When I went to take my written test in September, all they gave me was chapter 14. When I went to take the driving test, they would not let me take it since I had not taken and passed chapter 6. I will now have to go back and take and pass the chapter 6 test in order to be able to take the driving test. So be aware that this is a requirement now.