Texas Government Code - GOV'T § 660.008. Travel Expenses Incurred While on Leave

(1) the leave is used while the employee is away from the employee's designated headquarters;

(2) the primary purpose of the employee's being away is to conduct official state business;  and

(3) the agency determines that returning the employee to the employee's designated headquarters while using the leave would not be cost effective or would be impracticable.