Wivenhoe cycle lane road workers 'threatened over diversion'
CCTV cameras have been put up over roadworks after staff were repeatedly threatened by motorists, including by a man with a knuckleduster.
Angry drivers facing a 5.7-mile (9km) diversion around the £1.3m Wivenhoe cycle lane roadworks have confronted staff.
A number of incidents have been reported to police.
One worker there told the BBC that threats and verbal abuse were "not acceptable".
Pat Sheehan, a safety adviser for a construction firm, said he had heard of cases elsewhere in England of urine being hurled at workers.
The work in Wivenhoe has meant the closure of Colchester Road and a 5.7-mile diversion through Alresford.
Tim, the worker in Wivenhoe who asked for his surname to be withheld, told BBC Essex: "People have been known on occasion to get violent.
"One of my colleagues who was working at the top of Wivenhoe had a gentleman pull up in a car and he had a knuckleduster in his hand - which was quite frightening for him - and there's a lot of verbal abuse. It was reported to police.
"There have been three or four occasions which have been reported.
"I do understand people's frustrations but we're here to do a job and are trying to do it safely."
The works, which started in November, were expected to be finished by the end of March.
Mr Sheehan, health and safety manager for construction firm Colas and who leads the Highway Term Maintenance Association's roadwork safety group, said abuse of road workers was a "daily occurrence" across the country.
"People have been shot at with air rifles - you name it and it's happened. People have been spat at and driven at," he said.
On another occasion, he said, road workers had to flee two men armed with a machete. On a number of occasions, he said, urine had been hurled at road workers.