In this related questionthis related question, I asserted that it was illegal to be in neutral gear while stopped at a red light. The first comment to that question challenged me to quote chapter and verse.
Astonishingly, I may have been taken in by popular rumor. There are a lot of assertions that this is illegal in various places, a lot of questions indicating driving instructors are teaching that it is so, and a lot of recommendations for or against actually doing it for a number of reasons. However, there are also assertions that for a manual transmission, you must put it into neutral as part of coming to a "complete stop" (neutral gear, along with applying the handbrake, seems to be required in the UK).
Where the confusion may seem to come from is that it is illegal in most jurisdictions to coast while in neutral; you may only shift to neutral while moving if you are transitioning between gears. Therefore, the practice of shifting into neutral when approaching a stoplight is prohibited by many states' driving laws. It's also illegal, in some more mountainous U.S. States such as Minnesota, to leave a car unattended without the brake set and the wheels turned to the curb (Minn. Statutes 169.36), which has also been misconstrued to mean that the transmission must be in gear (to provide further rolling resistance).
So the question to be answered is, does any law currently on the books of any U.S. State or territory, or any local jurisdiction thereof, prohibit shifting into neutral while stopped on a roadway, in a situation other than while legally parking?