On August 21, 1923, SH 12 had lost much of its assignment, being mostly confined to south and southeast Texas. The Eagle Pass-Laredo and Refugio-Rockport segments had never been built. The section of SH 12 from Corpus Christi to Gregory was transferred to the new SH 16, and the section of SH 12 from Gregory to Rockport was handed over to the new SH 57. SH 12C was handed over to the new SH 60. SH 12 at this time followed the routing from Brownsville via Pharr to Alice. From Alice, SH 12 followed SH 359 to Skidmore, US 181 to Beeville, and US 59 to Rosenberg. SH 12B was cancelled and reassigned to the old route of SH 12 from Pharr to Laredo.