Westcountry members of the European Parliament have helped to defeat Brussels-proposed speed limits on quad bikes that would have rendered the vehicles "useless".
Farming leaders have hailed the vote as a victory for common sense after the European Commission failed to reduce top speeds for all-terrain vehicles to just over 24mph and change design features.
Under the proposal, bikes used in agriculture would have had to meet the same rules and regulations that govern quads driven on public roads.
The National Farmers' Union (NFU) argued the rules would remove the ability of quad bikes to perform off-road, while offering no worthwhile safety gain.
Critics argued manufacturers would have to build the vehicles to an on-road specification, pushing up their costs and severely limiting their effectiveness for farmers.
But MEPs have now voted against the changes in Strasbourg.
Conservative South West MEP Julie Girling said: "Quad bikes have become a familiar sight on the green rolling hills of the Westcountry and an indispensable piece of equipment in many farms – often used to check livestock and to haul feed.
"The proposals threatened to drastically increase the cost of farmers' quad bikes while perversely also making them more dangerous to use on farms.
"Quad bikes would have had to have ABS brakes installed and would have had to meet strict emissions limits, despite the fact that they generally don't clock up too many miles climbing up and down muddy hillsides.
"Hill farmers in the Westcountry would have been disproportionately affected due to the relatively high number of hill farms."
But, she added, the European Parliament had eventually "seen sense".
Instead of the proposed restrictions, a new category of all-terrain vehicles covering tractors and other agricultural vehicles has been introduced, allowing farmers to continue to use their quad bikes.
NFU regulatory affairs adviser Ben Ellis said: "Of course safety is our top priority for farmers, but the proposed rules would have reduced the ability of quad bikes to perform everyday functions."