Worst Endings to a Highway

[roadman65]

The north end of PA's I-476 with its 180 degree turn into a toll plaza counts.

Indeed it does. 

Though  I think  someone pointed out that this curve is there because original plans had the N.E. Extension continuing north along the path taken by "free" I-81. 

Correct.  If you look closely you will see the stub left behind that would have been the continuation of the NE Extension along the outside of the curve. 

Hopefully, either PennDOT or the PTC will make use of it and make a better connection to I-81 NB and from I-81 SB to the Turnpike someday.  Maybe after NASA lands men on Mars it will happen.

[Mergingtraffic]

The Richmond Parkway on Staten Island might qualify for both "worst end" in terms of cancellation (because of the resulting traffic impact on I-278 due to traffic having to go up NY-440 and then all the way across on I-278 instead of cutting off about half of the latter's mileage) and in terms of "how" it actually ends (it dumps traffic onto its western service road, which then ends at Richmond Avenue, but the parkway itself continues for a short distance over unused pavement and abandoned overpasses to an abrupt end at Richmond Avenue). Other thing is, if you follow the most logical route from the end of the parkway, you wind up going so far back to the west that you haven't cut off much of I-278 at all.

Image here. The parkway should be obvious in the middle of the screen. If you zoom it out or pan the image you can find the ghost ramps where the road would have ended at I-278.

I seem to remember an original "Arden Ave" BGS over the non used portion.  I remember seeing pics of it on the internet but didn't see any overhead sign on the Bing map you posted. 

[national highway 1]

The fact that CA 110 peters out into some surface streets in Pasadena; it really needs to be properly connected to I-210.