"We must keep our people safe and the public has a big part to play in that."
He said losing workers in a triple fatal truck crash in the Bay of Plenty on February 26, had highlighted how vulnerable they were.
"We strongly encourage drivers to slow down around work sites and keep to the speed restrictions in place.
"We are working with our teams, and across the industry, determine what more we can do to ensure our people go home safely every day."
Hawke's Bay road policing manager Matt Broderick said he understood that being asked to slow down in what is normally a 100km/h area could feel like you were stopping completely.
But the temporary speed limits were for the safety of those on the side of the road, he said.
He said when travelling on a road, any stones you flick up will travel at the speed your car is going.
If you were driving 80km/h an hour, the stone would too, and being hit by a stone going 80km/h hurts, Broderick said.
Mistakes on our roads do happen, and the only thing between vehicles and the workers are road cones.
He said a person only need stand on the side of an open road to understand how it feels to be doing road works on our 100km/h roads.
Legally, all temporary speed limits must be obeyed, according to the New Zealand Road Code.