I bought a flag for bikecamping trips on a not so busy two lane highway,figuring some drivers might be daydreaming or just not paying attention. Haven’t used it yet.
https://cimg6.ibsrv.net/gimg/bikefor...788d14bd5.jpeg

The airbag helmets do exist.

https://hovding.com/#

I'm not sure I'd be ready for one, but it is possible that they could be made to be safer than ordinary bike helmets.

There are also airbags for horseback riders.

https://www.rideequisafe.com/collections/air-vests

However, a fall off a horse is very different than a bicycle crash (or getting hit). I know of a person who wears an air vest every time she rides her horse.

Nonetheless, the Hövding proves that a bicycle airbag is possible, and can be triggered.

Undoubtedly there is more research in bike safety that can be done.

I feel like bike lanes only go so far since many that i ride on don't have a physical barrier. Many of my friends avoid bike lanes and ride one street over.

I recall seeing a guy riding with a 3’ slender flag pole attached to the back of his bike with a flag on the end extended to the lane on his left forcing cars to drive to mis the flag. Imagine a flashing LED could be mounted too. There may have been a spring the pole attached to so if it was struck, it would flex. Something like that might be good for night and early dawn/dusk commuters. Also saw an LED or laser device mounted to the bike that projected a 3’ bike lane to the left of the rider. As he rode the bike lane rode along with him. Bizarre but ingenious in low or no light conditions.

the projected bike lane was better than this, but this is the general idea: https://www.amazon.com/Rechargeable-...NsaWNrPXRydWU=