Watch Kathy Wardle's report.
Cornwall Council is being taken to court over its decision to go ahead with a controversial cycle path.
A group of businesses on the Newham Industrial Estate in Truro claim the scheme is dangerous.
They now want the High Court to review the council’s decision and get the work stopped.
Janet Martin, manager at Tile Wise, said: "The road’s just getting busier and busier, it’s ludicrous to think that they would be narrowing the road.
"Two lorries getting past is ridiculous and to narrow it even further, that would be ludicrous."
The Cornwall Council scheme along a 350 metre stretch of Newham Road will create a wider footpath for pedestrians and cyclists.
A total of 45 businesses objected to the plans and a road safety study commissioned by Newham Business Improvement District said the scheme was likely to cause “extreme danger”.
Newham BID is now seeking permission from the High Court to judicially review the council’s decision to go ahead with the scheme.
Campaigners are seeking an injunction to prevent further work from happening until the case reaches court.
Cameron Macquarrie, managing director at Macsalvors, said: "The problem is you’ve got cyclists in close proximity to the vehicles. In order to pass the wing mirrors etc. are going to be hanging over the pavement."
Cornwall Council said widening the footpath, creating a shared pedestrian and cycle path is part of the community-led Truro Loops Project to improve healthy transport links.
Janet Martin said: "Anything like that I am really, really up for, but this is not the place to be putting it. We do not want to put people at risk."
The council added that it could not comment further until the legal challenge was resolved.