Legislative punctuation is an animal all its own.
One thing learned during my life in California is police officers will often stop cars late at night for not using a signal. They may just be checking for drunks, profiling, raising revenue or just plain unaware of the law's interpretation of, "a signal is required as it affects traffic." (which is the wording in the CA Vehicle Code)

Judges have looked at that and decided if there is no other traffic to affect a signal isn't needed. My habit of signaling for everything has me signaling in my driveway at times.

jtk