Originally Posted by
mstateglfr
It probably isnt safer in heavy traffic. In low traffic settings, you are aware of cars approaching and can adjust how you are riding if you feel it necessary(like if 2 lanes become 1 in a short bit ahead due to construction or a curve, etc).
Its fantastic for gravel where the cyclist is continually adjusting their line and that often times means riding in the middle of the road. A visual and audible notification that a car is approaching allows the cyclist time to move to the right and not inconvenience the driver.
The Varia is 65lumens for daytime flash mode. That seems pretty bright.
I've ridden with many riders who have "radar" to announce the rear approach of cars. Other than the rare circumstance (like passing a slower rider), I've never seen them actually ride any different with the knowledge afforded them. Knowing something without using that knowledge seems pretty pointless.
That's my experience in my area which is central NJ where traffic is a given. There may be other places where the knowledge of vehicles coming from behind could be useful. Around here, just ride assuming there will ALWAYS be cars coming from behind.