Sec. 1.

(1) The state trunk line highway system of this state shall consist of all roads, streets, and highways, either located within or outside the limits of incorporated cities and villages, now or hereafter constituted state trunk line highways under the laws of this state. The director of the state transportation department may, from time to time, make and establish such subordinate classifications or groupings of state trunk line highways as the state transportation department deems necessary or desirable for proper administration of the state trunk line highway system. Additions to and deletions from the state trunk line highway system may be made from time to time in the manner prescribed by law. All roads, streets, and highways included in the state trunk line highway system shall be known and may be referred to for all purposes as state trunk line highways.

(2) Beginning on the effective date of the amendatory act that added this subsection and continuing to December 31, 2010, the state transportation department may designate 1 or more lanes of highway US 12 in a city of over 700,000 population as high-occupancy vehicle lanes, referred to as HOV lanes. Subject to the Michigan vehicle code, 1949 PA 300, MCL 257.1 to 257.923, when lanes have been designated and marked as HOV lanes, as the state transportation department may prescribe, lanes may be reserved during periods determined by the state transportation department for the exclusive use of buses and high-occupancy vehicles. Pursuant to the Michigan vehicle code, 1949 PA 300, MCL 257.1 to 257.923, HOV lanes may be reserved for high-occupancy vehicles carrying no fewer than 2 occupants including the driver.