Riders exercising their horses in the lanes around Soho Farmhouse are being warned to wear hi-viz for their safety.
Contributors on a Duns Tew Facebook page posted a photo of two riders on brown horses wearing dull clothes.
A motorist who overtook two horses wrote: “You were both totally invisible as we approached you because you had no hi-viz clothing on.
“You were round a bend and we would only have seen you from the waist up. You blended into the full colours of the hedgerow absolutely perfectly.”
“If you get knocked off a horse by a car then the horse will probably have to be put down due to its injuries. You will be seriously injured or killed. The car occupants will suffer. Everyone that attends the incident will be affected.”
One reader said: “Despite wearing high viz and having small children on ponies we are very often overtaken by lunatics driving far too close, far too fast.”
Recent planning applications in West Oxfordshire have received complaints that traffic is increasing with the rising popularity of the celebrity country club Soho Farmhouse - and getting faster.
The British Horse Society (BHS) advises horse riders to put hi-viz wear on themselves andtheir horses . The society regularly runs campaigns urging riders to make sure they are seen and appealing to motorists to treat horses on the roads very carefully.
The BHS asks drivers to slow down, pass wide and be patient when overtaking horse riders on the road.
Press officer Alex Whitton said: “We would recommend a minimum of a hi-viz tabard or jacket for the rider, and leg bands for the horse.”
The BHS says there is no law that states riders must wear hi-viz, but it is in their best interests to do so. Hi-viz should not just be worn on the road, but off road too.
Research by the Ministry of Defence has shown that helicopter pilots could potentially see a rider in hi-viz gear up to half a mile sooner, giving them more time to react and take avoiding action where possible.
It also means that in the unfortunate event that a rider is thrown from their horse and left in open countryside, they may be seen much sooner and hopefully prevent their injuries from becoming more serious.