OK US 64: US81_N and _S: Add US 60? By lower number, should be 60/81_E and 60/81_W but is what's there good enough?
If I were drafting this now, I'd probably use US60_W & US60_E. But, ehh.... good enough?
OK US 283/I-40 BL Sayre: Maybe add point at El Dorado Avenue for those following 66 (as I did, but I spun south to hit the ramps and came back).
Forgive me while I split hairs...
Historically, it looks like the connection was made at
what's now Thunderbird Dr. Of course, even that intersection was slightly doglegged, cutting out some of the curvature of the original roadway... What path, of those available today, best approximates the real historic route? Or, what path are travelers going to know about and be likely to use? OSM & Google show El Dorado & the connection thereto in a darker color, with Google even marking El Dorado as "Rte 66"...
Where to put it...
OK OK 58 (Medicine Park): Fun with frontage roads! NB 58 is signed on the north frontage (i.e. 66) while SB 58 is signed on the south frontage. Are the halves of the interchange far enough apart that they should be split (into 88A and 88B I guess)? Also if Hist 66 is extended this route would need to change to match.
IIRC This got some discussion a while back, maybe in the USAUSH thread. For interchange halves centered at the I-40 centerline & crossroads, I get 0.49 mi, even if I move the waypoints a bit farther apart than they'd normally be. Works out nicely in that a point in the center of our OK-58 "couplet" system matches the center of the I-40 interchange, and we get a graph connection. US66HisWea, on just the N frontage rd, is the odd one out here.