43 Tex. Admin. Code § 25.975
(a) The department will classify motor vehicle crashes by the standards established in the following manuals available through the department web site at www.txdot.gov:
Source Note:The provisions of this §25.975 adopted to be effective October 16, 2008, 33 TexReg 8558; amended to be effective December 12, 2013, 38 TexReg 8928.