case-by-case basis.
in the past year-ish, most of the time an audible alertness has shown to be ineffective. Doesn't matter the activity they're engaged in; walking, running, recumbent, E-Bicycle, etc etc. Some don't even have ear-buds in or a phone glued to there face. Common offending group tend to have an early 90s timeless attire & if there vehicle is nearby, ingress to a modern Buick branded vehicle.
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-Oh Hey!