SH-99 is certainly growing, though. The segment between I-10 and I-69 South should’ve been / needs to be built with at least 6 lanes, if not 8. And having the current situation where the mainline is free except at interchanges where the overpasses are tolled creates a situation where toll “dodgers” exit and re-enter the highway at every junction, increasing the choke points on the merges. Then the substandard areas that are narrow and lack any shoulders, and a couple areas with “at-grade” intersections, curb and gutter, etc. to nowhere with a wide median for a future overpass - because there’s no actual road intersection, there’s no interruption to traffic flow, but it’s still a very substandard design regardless.
Expand the highway to a proper 6-8 lane throughout, full interstate standard design, 70 mph, and eliminate the “free areas” or at least construct continuous running frontage roads so “free” traffic isn’t entering the mainline then getting off at the next exit. The mainline should be fully tolled.
Also, the I-69 South interchange badly needs to be upgraded to at least include a flyover between I-69 North and SH-99 North. That interchange backs up badly during peak hours with traffic having to exit, wait at the light, and turn left, just to transition between two freeways.