it seems alot of our laws are open to interpertation.When they were written,i dont supose they could ever have thought of half the scenarios that happen on the roads today.They need to be re written, or at least ammended.
Im the mean time, its up to police to interpet the laws as best as possible, and drivers to practice the safest possible defensive driving habits.
That is the best thing to do.Mandatory or not, the safest thing to do, is signal.Thats all.