Do seat belt laws specifically state that shoulder straps must also be used?
I agree with you about the upper strap. I think that seat belt laws are in a category which I believe to be an unconstitutional intrusion into our choices. The state should not be able to regulate our personal choices which harm nobody else. (Please see below) However, most officers are trained to look at the upper part of the strap as an indicator of non-compliance. If not fully applied, many states consider it not in use. This depends upon your state – which you do not mention. You might well be able to articulate to an officer or judge why you chose to disable part of the belt, but this will not keep you from being pulled over and possibly having to go to court if you have met with a rigid officer or one who has been given a rigid enforcement policy. If this is a serious concern to you for specific physical reasons (such as being very short and thereby endangered by the belt) you could contact the District Attorney or Attorney General for your area and attempt to obtain a written ad