Map of US highway 64 and family, and US 412

US 64 is represented by the purple line from Nags Head NC to Teec Nos Pos AZ. Its original route between Capulin NM and Boise City (in Oklahoma's panhandle) is shown in red. Also shown in red is its historic routing between Santa Fe and Taos NM.

US 164 [I] (historic) is the red line from Enid OK to Amarillo TX.

US 164 [II] (historic) is the red line from Cortez CO to Flagstaff AZ. US 64 never connected with US 164 [II]. While modern US 64 does connect with the historic route of US 164 at Teec Nos Pos, US 64 actually ended in Santa Fe during the time when US 164 existed.
The green line west of Teec Nos Pos is a suggestion: I think the US 64 designation should be extended along historic US 164, replacing the road's current designation (US 160). US 64 could end where US 160 currently ends (near Tuba City), but I think it would be even better to extend it along AZ hwy. 64, through Grand Canyon National Park, ending at I-40 in Williams AZ.

US 264 is the blue line from Manns Harbor to Raleigh NC.

US 412 is also shown on this map (the green line from Columbia TN to Springer NM). Because its number is a major violation of US route numbering conventions, I included it on this map to demonstrate how the highway would fit into the US 64 family, if it were to be assigned a number US x64. (This is just one of several other possibilities that make more sense than 412; I've also included the route on the maps for US 56, US 60, US 62, and US 70).