Tex. Ins. Code § 1806.052

This subchapter may not be construed to prohibit the modification of rates by a rating plan that is filed in accordance with the requirements of Chapter 2251 or Article 5.13-2, as applicable, that has not been disapproved by the commissioner, and that is designed to encourage the prevention of accidents, and to account for all relevant factors inside and outside this state, including the peculiar hazards and experience of past and prospective individual risks.