Common courtesy suggests that you should dim your headlights when approaching an oncoming vehicle. With today's high intensity LED headlights, this becomes more than a matter of courtesy but also potentially impacts public safety. Some drivers have forgotten to read their owner's manual and apparently don't know how to dim their headlights, especially when it [...]

Common courtesy suggests that you should dim your headlights when approaching an oncoming vehicle.
With today's high intensity LED headlights, this becomes more than a matter of courtesy but also potentially impacts public safety.
Some drivers have forgotten to read their owner's manual and apparently don't know how to dim their headlights, especially when it comes to passing an oncoming bicycle at night.
On about any night ride these days, I'll typically pass one or two motorists who have forgotten how to operate their vehicle's high beam/low beam function. Perhaps it's time to study up on that vehicle owner's manual, as it might save you some money.
According to Kansas Statute 8-1725 there is a $75 fine for 'failure to dim headlights.' The Kansas Driver's License Handbook states that you must do this when approaching within 500 feet of an oncoming vehicle (which includes human-powered vehicles).
My bicycle helmet light has three modes: bright, dim, and flashing. To try to get the attention of the driver of a vehicle seemingly stuck in high-beam mode, I will click through the three modes a couple of times, finally leaving the light set on flashing mode. It's the only way to let the driver know that, hey, there's a human being coming toward you who is going to be just as visible as you are with your high beam lights.
Please remember that cyclists are blinded by high beam lights just as much as other drivers are, perhaps even more so.
Another way to remember to switch from high beam to low is this little ditty I came up with:
'Don't be a dimwit, dim your brights.'