Idaho Code § 49-643: Highway construction and maintenance.

(1) The driver of a vehicle shall yield the right-of-way to any vehicle or pedestrian actually engaged in work upon a highway within any highway construction or maintenance area indicated by traffic-control devices.

(2) The driver of a vehicle shall yield the right-of-way to any authorized vehicle obviously and actually engaged in work upon a highway whenever that vehicle displays flashing lights meeting the requirements adopted by the board.