Originally Posted by
droy45
600-650 lumens should be the most you would want to use on the roadways as you have to remember your dealing with other vehicles and don't want to flash drivers with overly bright lights. I hear of those insanely bright lights like 1600+ lumens which should be used only in the forest trails at night. I have a 350 lumen light that is more than adequate for my commute. I tested 3 levels with a test driver before purchasing and we arrived on anything in the 600 lumen or less range did not produce and ill effects on the driver.
This is my opinion as well. I have a light capable of 1200 lumens, but I run it on low almost exclusively when in the city. A nice bright, solid headlight allows drivers to identify you and more accurately estimate your distance and speed. Flashing headlights are not a great idea...it's not enough to just get a driver's attention. The driver needs to be able to figure what to do with you.