(a) The commission by order may designate and the department may finance, design, construct, operate, or maintain one or more lanes of a state highway facility as exclusive lanes.
(b) The commission may designate a lane as an exclusive lane under Subsection (a) only if the commission determines that:
(1) there:
(A) are two or more lanes adjacent to the proposed exclusive lane for the use of vehicles other than vehicles for which the lane is restricted; or
(B) is a multilane facility adjacent to the proposed exclusive lane for the use of vehicles other than vehicles for which the lane is restricted; and
(2) the use or operation of the exclusive lane is likely to enhance safety, mobility, or air quality.

(c) The adjacent lanes or adjacent multilane facility under Subsection (b) may be designated as exclusive lanes or an exclusive lane facility for the use of vehicles that are prohibited from using the exclusive lane.
(d) The commission may authorize the operation of a vehicle that exceeds the weight limitations of Subchapter B, Chapter 621, or the size limitations of Subchapter C, Chapter 621, on a lane designated as an exclusive lane under this section if supported by an engineering and traffic study that includes an analysis of the structural capacity of bridges and pavements, current and projected traffic patterns and volume, and potential effects on public safety. This subsection does not authorize the operation of a vehicle that exceeds a maximum axle weight authorized by Chapter 621, 622, or 623. This subsection does not apply to a roadway that is a part of the national system of interstate and defense highways.