There is a difference that you brought up between your activity and that of what we are talking about. Yours is a practical purpose of transporting your rifle to the gun range on foot. The circumstances cannot be equally transcribed to random appearances in various social venues like urban coffee shops, restaurants, malls, and Wal*mart. What I am asserting is that unchecked, the advocacy to transport long guns in these circumstances outside any practical use, is going to escalate the conflict to a legislative solution that will mandate that your walks to the range require you to transport in a secure locked case.
While communicating your intentions to law enforcement in advance may soften the encounter, the police still view this as a problem they must respond to. This means more meaningless goosechases and more effort, which police cheifs will still take notice of. (Something that I believe we were about to overcome with handguns, before AB144 had been fully fleshed out.)