Crazy Highway Planning in North Carolina

While driving through North Carolina, I observed a highway design unlike any I'd seen before.

I'm familiar with the standard right-hand merge and the right-hand exit. I'm also familiar with the rare left-hand exit. Sometimes, it's just necessary.

What I've never seen before, and am flabbergasted that I saw at all, is the left-hand MERGE.

Who's bright idea is this?! Merging is the process of building up the speed of traffic joining the flow of the interstate. Common sense dictates bringing this slower traffic into the slower lanes - traditionally the right lanes.

The left lanes are for the fastest moving traffic So, who I the genius who thought that merging slow traffic into the fastest moving flow would be a safe, and wise, idea?

Just curious...