This is the divided section west of Hinkley. This was built in 1992.
This section probably lasts about five miles. It is a scenic highway, as long as you're not in Barstow, Bakersfield, Mojave, or Hinkley.
Here is the bottleneck. Here the divided section ends, and you ride on a two lane road (with purple asphalt) until just west of Kramer and US395.
Route 122 was supposed to meet 58 around here. The bottlenecks between Mojave and this point should be gone eventually, and this may some day be I40.