(a) The driver of any vehicle shall obey the traffic-control instructions of any law-enforcement officer or persons authorized by the commissioner of highways or by proper local authorities to operate traffic-control devices, act as flagmen or operate authorized vehicles engaged in work at or near the site of street or highway construction maintenance work, for the purpose of regulating, warning or guiding traffic, subject to the exceptions granted the driver of an authorized emergency vehicle in this chapter.
(b) Any person failing to comply with the requirements of this section is guilty of a misdemeanor and, upon conviction thereof, shall be fined not more than $100; upon a second conviction within one year thereafter, shall be fined not more than $200; and upon a third or subsequent conviction, shall be fined not more than $500.