But they don't seem to have widened I-45 beyond its existing six lanes. So there are basically twelve lanes of traffic merging into six at that location.
I'm nearly certain the interior shoulders of I-45 are being converted to traffic lanes, to make it 4x4. I haven't driven that segment since May, but work was well underway at that time. Yes, it's still going to be a problem to merge US 175 traffic into I-45.
For those not familiar, that section of I-45 was the site of the first major anti-freeway controversy in Dallas, which was in 1970. Original plans called for an elevated freeway. The very low income, predominantly black area protested and received substantial political backing. so TxDOT lowered the freeway to the ground and built it on the narrowest possible right-of-way. Even though the properties along the freeway are very substandard and distressed (and include a liquor store with a Big Tex sign), there was no way local interests were going to let TxDOT widen the right-of-way. Hence, the conversion of the interior shoulders into traffic lanes. It will be interested to see how much of a traffic issue develops on that section.
Some more background from the book. I cite this as the first removal of a structurally sound, non-dead-end freeway. Although (as some have noted) this could be classified as a relocation, even though it is only for a fraction of the original length. In my view, this would be a relocation if the new freeway connected to both endpoints of the removed freeway, which is not the case.

Here's an excellent view of the entire corridor
