As summer gets into full swing and the school holidays are approaching, the Farmers' Union of Wales is calling on drivers of all slow moving vehicles to defuse road rage by moving over and allowing faster traffic to pass.
"Getting stuck behind a slow moving vehicle on a twisting country lane with no opportunity to overtake is very frustrating," said Richard Vaughan, chairman of the FUW's land use committee.
"It is especially annoying on hot summer days for local people who are anxious to keep appointments and for tourists whose enjoyment of their holidays can be spoiled.
"The thoughtlessness of some drivers who forget to pull over when they are being followed by a long line of traffic is a recipe for road rage," said Mr Vaughan.
"It can often lead to drivers taking unnecessary risks and overtaking at the most inappropriate times and places, creating a danger to themselves and to other road users."
Although tractors are often blamed for hold-ups, slow-moving lorries and cars towing caravans could also be at fault.
"The Highway Code states that anyone causing traffic to back up as a result of their slow speed must pull over at the earliest and safest opportunity to allow faster vehicles to pass," he said.
"The FUW is reminding all drivers of slow moving vehicles to think of other road users and to follow the Highway Code."