1935 Texaco map of the US with weird US highway routings

[Max Rockatansky]

On US-50 stopped in eastern Nevada according to the map.

Swung north to US 40 since it wasn't built yet east of Ely. 

[Mapmikey]

We already knew Tennessee refused to sign US 270 because they wanted US 70S badly, and therefore no US 270 existed until the current route was designated in 1930. However judging by the map on the OP it appears by the mid-30s TN 26 was designated as the third US 70 route between Nashville and Crossville (strangely they didn't go with US 70C). And the map shows all three routes as US 70! However the 1939 map shows that TN 26 wasn't yet signed as US 70.

Also, per what it has been said it appears (contrary to popular belief) Tennessee accepted the changes proposed by AASHO but Kentucky rejected them, hence why several split routes still exist to this day. US 45E/45W may have barely entered Kentucky, but it's now entirely in Tennessee, so they could change that to US 45 and Alt US 45 as proposed back then without waiting for their neighbors to go along.

Tennessee hadn't signed any of their US routes when they unilaterally renumbered 241, 270 and 511 (no later than Feb 1928).  They got approval from AASHO for 270 and 511's changes in June 1929 after they chastised Tennessee for doing that in Jan 1929.  They did not grant 241 right away because nobody had asked Kentucky.  I did not find a memo with Kentucky explicitly agreeing, but their 1929 Official map does have it as 41E.

The 3 US 70s is a complete error by the mapmaker.  Tennessee explicitly requested in 1934 that US 70N be moved to TN 24 and TN 26 between Lebanon and Sparta would no longer be a US route.

Tennessee IMO missed an opportunity to get rid of US 45W when they requested the US route corridor from Pascagoula MS to Jackson TN in 1955.  Had they suggest US 47 (which fit the grid) and suggested it could replace US 45W too, maybe AASHO would've approved it.

[CNGL-Leudimin]

I stand corrected. US 70N originally went from Lebanon to Sparta (and the Sparta-Crossville section was "plain" US 70 like it's now), but was rerouted in 1934 (and thus US 270 US 70S was extended to Crossville as well). The triple split didn't came until the 60s or 70s.

[Avalanchez71]

Do you think that US 70 should be redesigned as US 70C between Lebanon and Crossville?

[US 89]

On US-50 stopped in eastern Nevada according to the map.

Swung north to US 40 since it wasn't built yet east of Ely.

The original US 50 definition did have a discontinuity between Ely and Thistle, Utah because it turned out the road from Ely across the desert to Delta was in terrible condition. I believe it took a few years for the routing via Wendover and Salt Lake City to be established as part of US 50. And even after 50 was eventually moved to what is now US 6 through eastern Nevada and western Utah, the old route through Salt Lake stayed around as Alt 50 well into the 1970s.

[hbelkins]

Do you think that US 70 should be redesigned as US 70C between Lebanon and Crossville?

I'd be in favor of decommissioning current US 70N, as it parallels I-40 and has basically been replaced by it, and renumbering existing US 70 as US 70N. Or do what's done west of Nashville and have US 70 and US 70A.