Possible explanation for the absurd location of US 319's south terminus?

[usends]

For those not familiar: the south end of US 319 is at a seemingly inexplicable location in the middle of a causeway, about a mile east of Apalachicola FL.  This is at the eastern foot of the "new" John Gorrie Bridge, which was built in 1988.  It replaced an earlier 1935 span, and on its approach into Apalachicola, the new bridge used a slightly different alignment.  Today the "End" assembly is posted right where the two alignments diverged.  (Here is the location on Street View, and you can view more photos and info here.)

During the mid- to late-1980s, Florida was pretty active about requesting permission from AASHTO whenever they made changes to their US routes.  Yet they never applied to move the terminus of US 319... which leads me to consider the possibility that FDoT never intentionally placed the terminus there.

I noticed the "End" assembly is posted exactly where the asphalt of the original alignment meets the concrete of the bridge's new alignment.  In other words, right at the project limit for the replacement bridge.  So I wonder if someone working on that project 30-some years ago misinterpreted a work instruction or something, and thought that US 98 was the only designation that the new bridge would carry, so they had an "End 319" sign placed right where the new bridge work was to begin?

Those of you familiar with road construction projects: how likely or unlikely is that scenario?  And who at FDoT might be able to provide some historical information to help answer this question?

[The Ghostbuster]

When US 98 was extended eastward, US 319 should have been truncated to this intersection: https://www.google.com/maps/@43.1068176,-89.328986,3a,75y,264.75h,90t/data=!3m6!1e1!3m4!1s6kmaJfzc-uNVrcS_gh5Org!2e0!7i13312!8i6656.

Then again, US Highways 17 and 701 were unnecessarily duplexed from Georgetown to Charleston from 1932 to 1992.

[Max Rockatansky]

Personally I've been in favor of routing US 319 down FL 300 to a new terminus on St. George Island, now that would be a neat south terminus.  In my time in Florida I never ran into anyone who had an explanation better than what was stated above for why US 319 ends where it does. 

[usends]

When US 98 was extended eastward, US 319 should have been truncated to this intersection: https://www.google.com/maps/@43.1068176,-89.328986,3a,75y,264.75h,90t/data=!3m6!1e1!3m4!1s6kmaJfzc-uNVrcS_gh5Org!2e0!7i13312!8i6656.

For me, that link leads to a location in Madison WI.  I was not aware US 319 ever went up that far 

[The Ghostbuster]

Sorry, that Google Maps location was meant for the "Massachusetts milepost exit numbering conversion contract" thread in the Northeast Regional Board. The location I intended for this thread was here: https://www.google.com/maps/@29.9191241,-84.5196776,446m/data=!3m1!1e3

I hope it stays on the correct location this time.