Under , of the Texas Transportation Code, the Texas Department of Transportation (TxDOT) has the authority to construct or designate exclusive lanes such as high occupancy vehicle (HOV) or managed lanes on the state highway system provided that proper traffic control devices are installed to ensure compliance with the lane designations. TxDOT may also enter into agreements with an outside entity to design, construct, operate, or maintain exclusive lanes. Exclusive lanes are intended to decrease traffic congestion, improve air quality, improve safety, and enhance the use of existing highways.