For many years, starting with the advent of the electric flashing turn signal, the front indicators emitted white light by means of a colourless incandescent bulb behind a colourless lens of one sort or another. This was in keeping with a longstanding colour convention of white for front lamps and red for rear ones. This is an account of two countries’ struggles toward rectitude in front turn signal specifications—the rear ones will have their turn, but not today.
In 1958, the (U.S.) Society of Automotive Engineers undertook a practical study of turn signals. In case you think that sounds all rigourous and scientific and stuff, it means the SAE Lighting Committee held meetings where they peered at cars equipped with a variety of signal configurations, and committee members voted on which setups they thought they liked best. One of the outcomes was a consensus that it would be better for front signals to be amber, the better to be discerned against reflections off chrome during the day…
…and against white headlamps at night. In theory, this recommendation wasn’t radical and caused no real disruption; in 1957—and probably quite a few years earlier, too, but 1957 is the oldest version I have—the SAE standards for both turn signals and parking lights already specified “white to amber”, a term still in use which means white or amber (as technically defined) or any shade in between. But practically, the push for amber front turn signals in the United States caused some serious friction; giant headaches, vociferous opposition, and dubious marketeering.
At the time, you see, there was no national, nationwide regulation of vehicle equipment, design, construction, or safety performance. That didn’t come in until the advent of the first Federal Motor Vehicle Safety Standards on 1/1/1968. There wasn’t even any legal structure in place for national regulation of vehicles, nor was there any federal agency with the authority to regulate motor vehicles, until the National Traffic and Motor Vehicle Safety Act of 1966 established the U.S. Department of Transportation and three relevant agencies: the National Highway Safety Agency, the National Traffic Safety Agency, and the National Highway Safety Bureau. These three agencies were consolidated into the National Highway Traffic Safety Administration (NHTSA) by the Highway Safety Act of 1970, but now I’m getting ahead of myself; the main thing is it was not possible for the US Government to require or specify anything in the way of vehicle equipment or design. That was left to the individual states, and most of them required type-approval by that state for each and every lighting device to be offered in that state on or for vehicles. And this was without any reciprocal recognition, so automakers had a giant amount of paperwork to do to get all their cars’ various exterior lights approved by each and every state in time for each new model’s first sale. Same for aftermarket repair and accessory parts. (funny, I don’t remember reading anything about this costly, unwieldy, restrictive, perpetual nuisance in the buff books’ screeds and jeremiads against federal regulation of vehicle design and construction).
It wasn’t a complete patchwork mishmash, for there was some coöperation among the states loosely coordinated through a series of associations of state motor vehicle administrators; a series of automaker associations, and (at a distance) SAE. 25 of the 50 states required white front turn signals and/or parking lights, and back then there was a quaint custom of states actually enforcing their vehicle regulations. So 25 states had to be coralled, cajoled, and convinced to change their laws. This typical article from the Tuscaloosa News on 24 January 1962 politely elides the enormous amount of sausagemaking involved; it reminds of that scene in “The Great Dictator” when Charlie Chaplin’s “Adenoid Hynkel” character shouts out a bunch of scornful, hateful pseudo-German, then the translator says His Excellency has just referred to the Jewish people: