[blacksmith_tb]

The idea would be more like the car, not the human behind the wheel, would realize that if it right-hooked me that would be bad (read insurance-increasing, citeable offense, etc.) and wait, where the driver would just keep flipping through their playlist and crush me.

[dmurray]

This just seems way better and more likely to be solved with lidar, or a similar passive solution, rather than relying on your bike to broadcast "this guy is more vulnerable/faster/more litigious than you expect, so be really sure not to clip him".

Even if the network was there, it's a difficult physical/technological problem to figure out everyone's relative position and velocity to suitable precision with something like GPS, or GPS + accelerometers. But mostly solved with lidar.