"Route 66" itself is an example of a vertically transmitted place meme. I call it vertical because the actual route and physical infrastructure (though rapidly degrading now) have existed over several generations. The essential meaning of the place name, "Route 66," has not changed over that time. In one sense however it is changing or, to be more precise, evolving.
In biological terms, evolution results in new species. In toponymic terms, evolution results in new places (but not necessarily in new names for them). I would argue that Route 66 is evolving into a new place. The route itself is a series of linked, named, places that, collectively, 'add up' to Route 66. Historically (roughly from the time my grandparents parents were driving until the time when my grandparents were passing away) Route 66 was continuous, stretching from Chicago to Los Angeles. Now the route is fragmented and the role it fulfills is a hybrid of actual road travel and commemoration.
As is well known, Route 66 is a symbol of American Freedom (see Jack Kerouac or the TV series "Route 66") writ large. My grandparents experienced freedom along this route, trailblazing their way across the midwest and southwest well before RVs and car camping had become popular pastimes. My grandma and grandpa would drive from their home in Stigler Oklahoma all the way to the Mojave Desert just for the fun of it. Back then the journey took four or five days. Now the same journey can be done in a day and a half.
If this is all more bewildering than illuminating, perhaps it will help to have a look at my paper Place Memes or even this one: Cree Ethnogeography. I include the latter mostly because I'm proud of it after months and months of revision and editing. The two papers were originally one. But the combination of the two proved theoretically convoluted, so I split them. But I would still maintain that Cree place-based practices and knowledge are memetic in nature. Memes are discrete (but overlapping) 'units' of cultural information. Place memes are similar 'units' of cultural information about place.
The 'unit' we call "Route 66" is a large, cumbersome, unit but it does refer to something real. It also refers to something imagined and in this sense memes (this is the first time I've made the connection) enter the realm of 'thirdspace' as theorized by Soja, especially in his books Postmodern Geographies and Thirdspace. A time or two I have been taken to task for sprinkling the word 'thirdspace' too liberally in my writing and theorizing. I do think, however, that this particular place meme warrants its invocation.