Business Loop I-35 - San Antonio

Prior to the 1991 decommissioning of U.S. 81 south of Fort Worth, old Laredo Highway was known as U.S. 81 Business between Exits 145 B and 154 A through southern San Antonio. A second business loop for U.S. 81 was also posted along old Austin Highway between Exits 158 and 166 through northern San Antonio. The southern business route was renumbered as Texas State Loop 353 while the northern section became Texas State Loop 368. Neither route was assigned Business Loop I-35F or I-35G respectively.

Some maps also showed a business loop for IH 35 encircling the San Antonio central business district. The route followed what is now the IH 35 mainline north along IH 10/U.S. 87 from Exit 153 and east to the current north end of IH 37 at U.S. 281 at Exit 158.