Officials say they had to pay millions of dollars to hire contractors to cut the grass near highways following tractor fires.

The state shelved the tractors last summer after three John Deere tractors used by the state for cutting grass alongside highways caught fire. Officials then hired contractors to cut the grass for $4 million.

“The safety of our employees is No. 1. And we couldn’t let them use those mowers until we knew that none of them were an issue,” state Transportation Commissioner Diane Gutierrez-Scaccetti said on Tuesday.

Gutierrez-Scaccetti told lawmakers in Trenton that more than 100 John Deere mowers had to be sidelined.

“Three of them caught fire, unfortunately, when people were in them mowing,” Gutierrez-Scaccetti said.

The state Department of Transportation hired contractors to cut the acres of roadside grass statewide through 2022 and racked up $4 million in fees.

“We made a decision last year to hire contractors because if we didn’t, you would call us and tell us we needed to mow the lawn. Because your constituents would tell you so,” Gutierrez-Scaccetti said.

The DOT bought 147 tractors from John Deere. Three caught fire - two were irreparable, and one could be repaired. One other tractor was hit by a car and totaled.

In a statement, the DOT wrote, “Fifty-three percent of these tractors and 71% of our overall full Tractor Mower Fleet are operational and currently in service to cut grass… NJDOT will not be financially liable for modifications completed to these tractors.”

“Given the fact that this appears to be a manufacturing defect, will we get that money back?” state Sen. Andrew Zwicker asked.

“We’ll reserve that position on how to deal with that $4 million with John Deere until we get our mowers fixed,” Gutierrez-Scaccetti answered. “They were reluctant to believe it was anything that had anything to do with the lawnmower.”

Gutierrez-Scaccetti also said that tolls on the New Jersey Turnpike and Garden State Parkway will go up starting next year.

The DOT says it does not plan to use contractors to cut grass this year.