My neighbor had a co-worker who was flagged down by a pedestrian last year. When he stopped, the pedestrian shoved him off his bike, grabbed the bike & rode away before the cyclist could even stand up.
A similar situation presented itself about 4 years ago. I was riding in South Seattle. A street person was walking in the middle of the road & tried to flag me down. I sped up. He looked more urgent & took another step towards my path. I moved over...& sped up. This happened a few times. At this point I was in a full 35mph sprint with my eyes locked on his & like him, my shoulder is down like I'm ready for football tackle impact. When he finally realizes "this is gonna hurt" he stands up & flails himself backwards as I go by.
I was very thankful the situation ended with out incident. Adrenaline powered fight mode doesn't last long.
Bike jacking is real.
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I shouldn't have to "make myself more visible;" Drivers should just stop running people over.
Car dependency is a tax.