Shortly after the automobile reached mainstream status, the need for safety features became necessary. It’s strange to consider that some early features actually required thought and innovation, but headlights, brake lights and turn signals are among such examples.
Lighting on cars was pretty sparse, and marker lights and reflectors were not required. In fact, a single taillight was standard, while an additional taillight on the opposite side of the vehicle was an option on many vehicles into the 1930s.
Turn signal colors corresponded to the colors of their adjacent lighting — white in front like headlights and red in back, often in the same housing as the taillights.
By 1963, regulators determined that front white turn signals should be amber to better define them in the glare of white headlights, and so it was that front turn signals on American cars followed their European examples, but that’s largely where the similarities end.
In the late 1970s, amber rear turn signals began to show up on American roads, especially as smaller, more fuel-efficient vehicles began pouring in from Japan and Europe to combat the fuel crisis of the time.
I remember thinking they seemed more modern and worldly, but like the metric system of my elementary school days, they didn’t catch on over here.
In this current regulatory laden automotive environment it comes as a surprise to me that rear turn signal colors are left up the the manufacturer to choose with both red and amber as acceptable.
Modern vehicles in the U.S. require back up cameras, tire pressure monitors and traction control — features that add significantly to the cost of production and maintenance, yet opting for a simple, proven safety feature like amber-colored turn signals are left to the automaker’s discretion.
By comparison, the addition of a third brake light to cars and light trucks in the U.S., mandated in 1986, reduced rear-end collisions by 4.3 percemt while as recently as 2009, a National Highway Traffic Safety Administration study on amber rear turn signals showed an effectiveness of 5.3 percent in reducing the same types of crashes.
This is not a ground-breaking discovery; Europe and most of the rest of the world require amber rear turn signals for safety reasons.
The trucking industry recognizes the significance of amber rear turn signals and most tankers use amber signals to take advantage of added safety, as these are vehicles that often carry hazardous materials.
It’s not that automotive rear lighting in the U.S. is completely unregulated. Brake and rear turn signals on American cars are required to have a minimum Effective Projected Luminous Lens Area, or the illuminated portion of the light, of 7¾ square inches, a parameter that doesn’t exist anywhere else in the world, where instead amber turn signals are the requirement.
This EPLLA can be a design constraint when trying to add a separate colored lens to the rear of a vehicle but this antiquated requirement was adopted in the 1950s using an arbitrary and subjective observation method as a determinant.
When NHTSA revisited the issue in 1993 they concluded that the intensity of the light rather that the lit area was a larger factor in attracting the attention of following drivers. Nevertheless, the EPPLA requirement was left unchanged because, applying governmental pretzel logic here, while NHTSA couldn’t find any reason to keep the rule, they couldn’t find any reason to eliminate it either.
Considering the rest of the world has required amber rear turn signals for 4 decades or more, there’s little cost to automakers to retrofit U.S. market vehicles to comply, although, perhaps doing so voluntarily would be looked at as a tacit admission that current rear red turn signals are less safe and could open up to potential liability.
Like most, I could do with less regulation from the government, and I don’t advocate adding more rules to the long list of new vehicle requirements, but when the mountain of data and studies, along with empirical evidence, suggests something as simple as changing a lens color could improve safety, it might be time to add a little amber.
Eric and Michelle Meltzer own and operate Fryeburg Motors, a licensed, full-service automotive sales and service facility at 299 Main St. in Fryeburg, Maine. More than a business, cars are a passion, and they appreciate anything that drives, rides, floats or flies.