In my area, a major road is part of the coast to coast US-6 highway system. Within the city limits the road is named Hickman Road. The road is signed Hickman Road on the street signs and also contains the usual US-6 badging.
There is an obscure historical name for this route called the "Grand Army of the Republic Highway." US-6 was commeratively named Grandy Army of the Republic Highway in 1953. Occasionaly along this road, there are historical, commerative signs that refer to this designation, much like signs that refer to historical points of interest. The DOT does not refer the road like this and there is no official road signage that refers to like this.
On Google Maps, the designation Grand Army of the Republic Highway is given way too much prominence. When you zoom out to an overview level, Google displays this obscure, historical name as the name it shows. In addition, when using Maps / Navigation, Google uses this obscure name as the road name that you are traveling on at the bottom of the screen.
While the historic nature of this road name should be used with Google Maps using the historical/obscure name feature, I don't believe that it should receive the level of prominence that it currently is receiving within Google Maps. I've lived here 20 years and when I first saw it on the maps I thought it was an error until I actually did some web research.