A few miles south of Miami, the old alignment of Route 66 narrows to a single strip of concrete barely nine feet wide running through farmland. This is one of the few surviving stretches of the original "sidewalk highway" — a thrifty 1920s engineering compromise that has somehow outlived the wider, faster roads that replaced it.
Drive it slowly. The asphalt is patched but the concrete itself is mostly the original surface. The old strip runs roughly between Miami and the village of Narcissa; it is signposted from US-69 as a Route 66 historic alignment.