Hector Fratty

from Daniel Stern, DVN General Editor

It’s difficult to make a headlamp, especially a low beam, that provides the driver with enough light to see safely at realistic roadways speeds. It’s always been one of our community’s most difficult problems, and we have long devoted an enormous amount of time, effort, and thought to it. Eventually developments like glare-free full-time high beams will do away with this particular challenge and replace it by new ones, and perhaps eventually—when we relinquish the entire driving task to the vehicle—headlamps as we now know them will be superfluous. But those days are far in the future, and for now we must continue to struggle towards safely effective low beams. Over the years and decades, headlamp photometric performance has steadily improved, and work toward that objective still continues.

The work involves more than just devising and applying new technology and technique in light sources and optics; regulators strive to specify lamps and installation protocols that guarantee adequate safety. But the regulations they write apply only to cars as they’re built, not as they’re used. a substantial chunk of the work we all put in is nullified and countervailed by the laws that apply to vehicles in use. These aren’t the UN (ECE) Regulations or SAE/FMVSS standards, but rather the jurisdictional laws that govern vehicle roadworthiness. In Europe, these are written at the national level. In countries like the US, Canada, and Australia, they’re written at the state or provincial level—and more often than not, they’re not even close to requiring at least the minimum safety performance stipulated by UN or FMVSS standards.

Right now, the laws of several European countries specify that a vehicle’s low beams are roadworthy if they illuminate an object 30 metres ahead on a straight road. Simple math tells us that thirty metres is a woefully inadequate preview distance, to put it mildly. In realistic terms, a 30-metre preview is a deadly collision waiting to happen. It’s just simply nowhere near enough at the speeds we actually drive. Presumably these meagre requirements are an ancient holdover from the feeble lighting of decades long past, but they’re still in force. And by their durability in the lawbooks, they have attained an undeserved aura of rectitude. Popular mythology has sprung up and taken on false legitimacy of its own to support such an inadequate roadworthiness standard; When a European motorist takes his car to a workshop for the headlamps to be aimed, it is common for the mechanics to aim them to the low end of the too-low specification “for safety”, a notion borne of the unsupportable premise that near-zero glare to oncoming traffic is the prime determinant of low beam safety performance.