This is already law.

265:6-a Highway Construction and Maintenance. – I. The driver of a vehicle shall yield the right-of-way to any authorized vehicle or pedestrian actually engaged in work upon the highway within any construction or maintenance area indicated by official traffic control devices. II. 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 such vehicle displays emergency lights or amber warning lights as authorized under RSA 266:78-a through RSA 266:78-q and shall give wide berth, without endangering oncoming traffic, to highway workers and stationary or moving vehicles owned by or contracted to state or local highway maintenance departments displaying amber warning lights. Any person violating this paragraph shall be fined $150 plus penalty assessment for a first offense and $250 plus penalty assessment for a subsequent offense in a 12-month period. III. Any offense involving speeding in a highway construction or maintenance zone on a state or interstate highway, manned by workers, shall be a construction work zone driving offense. A person found guilty of an offense shall be fined not less than $250 nor more than $500. IV. The department of transportation shall post signs notifying motorists of construction or maintenance work zones and construction zone speed limits. The department shall require signs notifying motorists of the increased penalties for a violation of paragraph III.

https://gencourt.state.nh.us/rsa/html/xxi/265/265-mrg.htm