Motorcyclists have staged a protest over wire crash barriers on a new dual carriageway in Norfolk and Suffolk.
More than 200 bikers rode through Norwich about 13:15 BST to increase awareness of their safety fears.
They claim the barriers on the A11 between Thetford and Barton Mills are dangerous because a rider could slide onto the opposite carriageway.
The Highways Agency, who installed the wire barriers, said they comply with approved standards.
Simon Frampton said the Highways Agency was not listening to their concerns and the motorcyclists would keep on protesting.
"With conventional solid or concrete barriers a motorcyclist would slide along them staying on the carriageway," he said.
"These cables are designed to absorb the power of a crash by stretching by about 4ft (1.5m).
"Even a vehicle hitting them would give the impression it was coming through to the opposite carriageway causing other road users to swerve.
"This could cause accidents on the opposite carriageway."
But he said motorcyclists also face serious injury if they hit one of the posts supporting the wires after coming off their vehicle.
"These posts are about 20 feet apart so in a crash a motorcyclist is in danger of hitting one."
A Highways Agency spokesperson said: "We are committed to providing safe roads for all road users and any safety barriers we install comply with approved standards.
"This section of the A11 is generally very straight and there has been no significant accident history regarding motorcycles.
"Wire rope safety fence has been installed because it is a compliant, approved system and is deemed to be an appropriate safety measure for this location."