A
2+1 setup on the 50 seems a low-cost and prudent means to improve safety until a final four-lane configuration can be eventually be achieved.
It mitigates the foolishness of risky passing maneuvers using the oncoming lanes. Since the 50 is (mostly?) grade-separated as-is, a barrier between oncoming traffic doesn't affect access to the road.
The alternating passing lanes ensure that traffic gets an opportunity to pass safely and at regular intervals.
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