Which Interstate/US Highway terminates the most of its peers?

[NWI_Irish96]

Nothing near the most, but in Indiana, US 20 terminates US 33, US 35 and I-65, which is a lot for anything not on a coast.

[StogieGuy7]

^In fact, I'm pretty sure I-5 is the only 2di to actually end at the border.  I-19 stops a couple blocks short, as does I-35, and I believe I've read that I-69W technically ends at Riverbank Drive due to the World Trade Bridge being commercial only.

You forgot at least one major 2 di: I-69, which goes right up to the Blue Water Bridge (Port Huron/Sarnia) and ends at the Canadian border.  Interstate 89 at Highgate, VT is likely another, as it is marked right up to the border.  And then there's I-93 at Derby Line, VT which also ends at the border with Quebec. 

[JayhawkCO]

^In fact, I'm pretty sure I-5 is the only 2di to actually end at the border.  I-19 stops a couple blocks short, as does I-35, and I believe I've read that I-69W technically ends at Riverbank Drive due to the World Trade Bridge being commercial only.

You forgot at least one major 2 di: I-69, which goes right up to the Blue Water Bridge (Port Huron/Sarnia) and ends at the Canadian border.  Interstate 89 at Highgate, VT is likely another, as it is marked right up to the border.  And then there's I-93 at Derby Line, VT which also ends at the border with Quebec.

The discussion was about interstates terminating on the southern border.

[US 89]

^In fact, I'm pretty sure I-5 is the only 2di to actually end at the border.  I-19 stops a couple blocks short, as does I-35, and I believe I've read that I-69W technically ends at Riverbank Drive due to the World Trade Bridge being commercial only.

You forgot at least one major 2 di: I-69, which goes right up to the Blue Water Bridge (Port Huron/Sarnia) and ends at the Canadian border.  Interstate 89 at Highgate, VT is likely another, as it is marked right up to the border.  And then there's I-93 at Derby Line, VT which also ends at the border with Quebec.

The discussion was about interstates terminating on the southern border.

If you broaden the scope a bit to include 3dis, I-110 in El Paso reaches the border. I believe it is the only 3di to do so.

[StogieGuy7]

^In fact, I'm pretty sure I-5 is the only 2di to actually end at the border.  I-19 stops a couple blocks short, as does I-35, and I believe I've read that I-69W technically ends at Riverbank Drive due to the World Trade Bridge being commercial only.

You forgot at least one major 2 di: I-69, which goes right up to the Blue Water Bridge (Port Huron/Sarnia) and ends at the Canadian border.  Interstate 89 at Highgate, VT is likely another, as it is marked right up to the border.  And then there's I-93 at Derby Line, VT which also ends at the border with Quebec.

The discussion was about interstates terminating on the southern border.

Honestly, I didn't sift through the entire thread to glean that.  And I wouldn't have guessed because the detail isn't all that important given that many interstates terminate right at the border and the engineering/administration of that interface is the same whether it's north or south.

[vdeane]

^In fact, I'm pretty sure I-5 is the only 2di to actually end at the border.  I-19 stops a couple blocks short, as does I-35, and I believe I've read that I-69W technically ends at Riverbank Drive due to the World Trade Bridge being commercial only.

You forgot at least one major 2 di: I-69, which goes right up to the Blue Water Bridge (Port Huron/Sarnia) and ends at the Canadian border.  Interstate 89 at Highgate, VT is likely another, as it is marked right up to the border.  And then there's I-93 at Derby Line, VT which also ends at the border with Quebec.

The discussion was about interstates terminating on the southern border.

Honestly, I didn't sift through the entire thread to glean that.  And I wouldn't have guessed because the detail isn't all that important given that many interstates terminate right at the border and the engineering/administration of that interface is the same whether it's north or south.

FYI, the ^ mark at the beginning of a post means that it is in reply to the one directly above it.

Lots of interstates (I-A1, I-5, I-15, I-29, I-75, I-94*, I-190, I-81, I-87, I-89, I-91, I-95) end at the Canadian border, which is why it's so weird that they tend to stop short of the Mexican border.  Incidentally, I've even heard conflicting reports on exactly where I-110 ends, so that's why I limited that comment to 2dis.

*I tend to view I-69 here as a bootleg interstate.  Unlike the infamous MMM I-80/90 discussion, they don't split again later, so it's a pointless overlap, and IIRC, I-94 was there first.