Texas Transportation Code - TRANSP § 257.004. Road District Signs

(a) A road district to which this chapter applies shall post signs indicating the existence of the district at two or more principal entrances to the district so that they are readable by traffic entering the district.  The signs must be posted not later than the 60th day after the date the district is established and must be maintained as long as the district exists.

(b) Consistent with state and local rules governing signs, the signs must be permanent and contain the name of the district in at least three-inch letters.  The signs may contain other information as determined by the commissioners court.