Texas Transportation Code - TRANSP § 224.004. State's Use of Eminent Domain

(a) If the commissioners court does not acquire a right-of-way under Section 224.003, the commission shall immediately serve the commissioners court with an order identifying the right-of-way by field notes and requesting the commissioners court to acquire the right-of-way.

(b) Not later than the 10th day after the date the order is served, the commission shall direct the attorney general to initiate eminent domain proceedings on behalf of the state to acquire the right-of-way.

(c) Venue is in the county in which the right-of-way is located.  The district or county attorney for that county shall initiate the eminent domain proceedings.

(d) Chapter 21, Property Code, governs the procedure for the eminent domain proceeding except that the county judge appoints the special commissioners.