Originally Posted by motor_oil_madman
I really think they need limit the total brightness a headlight can be. It's great that you can see better, but when everyone around you is blinded then that's a problem.
There really cannot be a brightness limit for headlamps. Implementing a brightness limit has never, ever been seriously considered by any regulator in the world, and it never will be, for good reason. Such a limit would simply cause more pedestrians fatalities and collisions with deer, etc. The very best headlamps on a $55,000 2020 Mercedes E-Class only illuminate out to 200 feet on the left side of the road. Let's say Johnny Jaywalker steps out from the left and in front of your E-Class. At a mere 40 MPH, you'd be hard-pressed to stop in less than 200 feet. At 45 MPH, Johnny Jaywalker is getting a free ride to the hospital. At 50+ MPH, Johnny Jaywalker is getting a one-way ticket to the morgue. And that's with a 2020 E-Class with the better (read: more expensive) headlamps in perfect condition and in perfect alignment--not a 10+ year old car with jaundiced lamps. And you'd be hard-pressed, even today, to find lamps as good as the ones on the E-Class. There's a reason deer alone cause $1 billion in property damage in the US every year. No one wants to hit a deer. They just drive at 70 MPH in the dark with just low-beams and magically expect low-beams to save them when the reality is that low-beams are good to 40 MPH, max.
The biggest cause of glare complaints today is the fact that the US does not require auto-leveling headlamps. A headlamp's point/region of high intensity is located at 0.6 degrees below the horizontal and 1.3 degrees to the right of the vertical. Simply having one passenger in the backseat will tilt your vehicle up sufficiently that this -0.6 degree value becomes something more like +0.1 degrees. In other words, a passenger in the back seat, your Harbor Freight aluminum jack in the trunk for quick roadside tire changes, a full tank of gas, etc. can and does tilt the car so that the zone of highest intensity is now in other drivers' eyes.
That's why so many people are quick to blame the Corolla has having "blinding" headlamps. The Corolla has, for one, no auto-leveling. It also has a very simple suspension setup, especially in the rear. This isn't a car made to smooth out bumps. This is a car that reacts to every bump on the road and the simple addition of stuff in the trunk or a passenger in the back brings the high-intensity zone dangerously close to oncoming drivers' eyes (or actually in their eyes).
Also, even extremely dim bulbs can put out dangerous levels of glare.
Finally, as far as "HID retrofits" go, no, getting a "proper" HID retrofit doesn't make one any better than the Corolla, unless your HID retrofit includes retrofitting an auto-leveling system. Clear lenses and other mods to boost the maximum intensity of your HID retrofit just exacerbate the issue of not having auto-leveling. Junk in your trunk, passengers in your car, suspension issues, even gas in the tank will change the dynamic aim of your lamps, and by boosting intensity to stratospheric levels with clear lenses and spacers, you end up possibly glaring other drivers with every bump in the road and passenger in the backseat. The presence of absence of a "cutoff" has little to no bearing on glare when a scientific study found that 90% of the time during driving, your lamps are not pointed in the optimal/right direction. A cutoff is a useless defense against glare when you have a friend in the backseat who's weight has caused the zone of highest intensity to rise from -0.6 degrees below the horizontal to +x degrees above the horizontal. In other words, static aim is important, but dynamic aim is truly where it's at with these high-intensity lamps on the market today, and engineers are taking steps toward enabling full dynamic aim with adaptive driving beam technology. Auto-leveling was a stepping-stone--an important one. And one that's still relevant; If the Corolla came with auto-leveling lamps tomorrow, the glare complaints will drop dramatically.
