I would have to be compelled by the real threat of some penalty before I would obey this law. I don't believe there is any moral or civil requirement to follow ridiculous unenforced or obsolete laws.
Regarding your freind, I would have found some ridiculous law in the jurisdiction of his residence and asked him to obey it. For instance, if your freind lived in Washington state ask him to obey this law (from
www.dumblaws.com)
All motor vehicles must be preceded by a man carrying a red flag (daytime) or a red lantern (nighttime) fifty feet in front of said vehicle.
Stu