^^^^^^^^^^^^^
As far as a "split alignment" for I-69 goes, that was attempted by a cadre of AR congressfolks 20+ years ago with what was termed the "Dickey Split", which didn't double up on I-30 and I-40 but ran a branch up US 79 until about Stuttgart, then veered east to cross into Mississippi somewhere near the US 49 bridge. While that was shot down, as a "consolation prize" the delegation got a I-69 branch (SIU #28) heading north from Monticello, tying in with I-530 at Pine Bluff. Since then, a sizeable chunk of the funds obtained so far by AR for construction of their share of the I-69 corridor has gone to extending AR 530 (familiar number?) south from Pine Bluff to near the E-W I-69 alignment at Monticello; so far, construction has been 2 lanes on a 4-lane ROW, more to reserve the ROW than anything. With that branch in place, the chances of reconsidering anything like the original Dickey Split are slim and none, particularly if the alternative simply dumps more traffic onto the already crowded I-30 and I-40 east of LR. But the idea of continuing the trunk I-69 corridor over US 79 to I-20 than simply replacing the south end of I-369 would be convincing if not for the fact that TxDOT is already planning a massive stack interchange at the 20/369 junction just east of Marshall; it's just as likely, considering the scope -- and overall cost -- of this and other in-state corridors, they would rather save some bucks, bite their cheeks, and tolerate a multiplex of I-69 with I-20 for the few miles east of Marshall to the state line.