I am new to New Jersey BUT I was led to believe you needed a hel

Cape May County - I am new to New Jersey BUT I was led to believe you needed a helmet to ride a bike on local streets and highways. BUT it is obvious I must have misread as in our shore towns - Sea Isle, Avalon, Stone Harbor - 80% of bike riders regardless of age are riding in our streets with NO helmets. Why is that? Where is local law enforcement? Why have a law without law enforcement?