Road workers were verbally abused, and objects thrown at them by people travelling through the Te Puke Highway site this morning, the NZ Transport Agency says.
Work to stabilise the Kaituna riverbank began on Monday, meaning the Te Puke Highway will be reduced to one lane and with Stop/Go traffic management for up to three weeks.
The agency said in a statement the road works were causing delays as anticipated.
Police had been contacted over "unacceptable driver behaviour" at the roadworks and there are plans to install security cameras.
"It has come to our attention our crew is getting verbally abused and objects thrown at them from disgruntled people", said Rob Campbell, Waka Kotahi NZ Transport Agency regional manager for maintenance and operations.