 On March 28, 1996, Loop 201 was redesignated as part of SH 146
SH 146 has two business routes.Business State Highway 146-D (formerly Loop 410) is a business loop that runs from SH 146 in La Porte to Spur 501.The highway was designated on December 1, 1971 as Loop 410 from SH 146 east, north, and west to SH 146, and was marked as a business route of SH 146.