23 V.S.A. § 1050a: Authorized highway maintenance vehicles

(a) As used in this section, “authorized vehicle” means a vehicle authorized by the Agency of Transportation (in the case of State highways) or the municipality (in the case of town highways) to perform maintenance on a highway.

(b) The driver of a vehicle shall yield the right of way to any authorized vehicle obviously and actually engaged in work upon a highway when the vehicle displays flashing lights meeting the requirements of subsection 1252(d) of this title.