In the United States, any vehicle that measures in at over 80 inches wide will fall under commercial vehicle guidelines. These vehicles must come equipped with “three amber front and three red rear identification lamps spaced between 6 and 12 inches apart at the center of the front and rear of the vehicle, as high as practicable,” as per the federal government, but this does not apply to the single-rear-wheel versions of the Chevrolet Silverado HD and GMC Sierra HD in California.
So, what’s the reasoning behind this? It turns out that California has a law that overrides this federal regulation and the reason why is a bit ridiculous, in our opinion. According to California Vehicle Code 27606, “no person shall own or operate a motor vehicle which is equipped with a light bar, or facsimile thereof, to resemble a motor vehicle used by a peace officer or traffic officer while on duty within that jurisdiction.” The law goes on to explain that a “light bar” can refer to “any light or device affixed to or mounted upon the roof of a vehicle and extending the width of the roof, or a substantial portion thereof, which emits amber, red, or blue, or any combination of those lights.”
Simply put, California law mandates that a vehicle cannot have an amber, red or blue light bar mounted to it that spans the width of the roof, as other motorists may confuse the vehicle for law enforcement. As such, Chevrolet Silverado HD and GMC Sierra HD trucks in California cannot be equipped with the amber roof marker lights (RPO code U01), which are typically a $55 option.
A GMC spokesperson provided a little more information in a statement emailed to GM Authority.
“At GMC, we are dedicated to working with all our stakeholders when building and delivering our vehicles and we will provide different vehicle configurations accordingly,” the automaker said. “For example, in California, local regulations require that our single rear-wheel Sierra HD trucks are not offered with amber roof marker lamps.”
In fact, this explains why the 2021 Chevrolet Silverado HD Carhartt Edition will not be sold in California, as it comes equipped with the amber roof marker lamps.
So if you’re a California resident wondering why not all configurations of the Chevy Silverado HD and GMC Sierra HD can be purchased with amber roof marker lamps in the state, now you know!