The M6 is said to make motorists feel nervous

As many as one-third of drivers admit to being anxious while using motorways, with older and younger women said to be the most affected.

Around 12% of 1,078 motorists surveyed by the RAC Foundation said they went out of their way to avoid motorways.

Symptoms of "motorway anxiety disorder" include increased heart rate and raised blood pressure, making people more prone to mistakes, the foundation said.

Other symptoms are excessive sweating, tension, headaches, stomach cramps and digestive problems.

Self-fulfilling prophecy

The most anxious 12% experienced anxiety levels more significant than if they were attending a job interview, visiting the dentist or going on a first date.

Professional male drivers between 28-55 tended to experience the lowest levels of motorway anxiety disorder, the foundation said.

Nervous drivers are more likely to make mistakes such as leaving the indicator on, driving at excessively low or fast speeds, staying in low gears and driving to close to the car in front.

UK'S SCARIEST MOTORWAYS M25 - "the road to hell" A1(M) - roundabouts M4/M5 interchange - confusing signs M1 junctions 28-32 - congestion M6 Birmingham - traffic mixing M4 Maidenhead - tailgating M27 Southampton - foreign drivers M8 Glasgow - slip road into fast lane M4 Wales - Severn Bridge M18 Doncaster - confusing junctions Source: RAC Foundation

Sarah Forrow, campaigns manager of the RAC Foundation, described the anxiety levels as worrying.

She said: "For many nervous drivers who venture onto the motorway there is a high risk of a self-fulfilling prophecy.

"They drive in an indecisive way which reinforces their fears, annoys other drivers, and can increase the risk of accidents on the motorway.

"We would urge anxious drivers to drive with a calm passenger, leave plenty of space between their vehicle and other vehicles, and practise their driving regularly."

But she added motorways are the UK's safest roads - drivers are seven times more likely to have accidents on urban roads.

Calming music

Conrad King, psychologist for the RAC Foundation, said for people to experience anxiety on the motorway was "quite natural and understandable"

He said: "This anxiety becomes a problem when drivers fail to get enough practice on the motorways, and so don't ever fully eliminate their fears.

"Some drivers build up their fears so much that they create new completely irrational fears which serve to reinforce their original anxiety."

He added anxiety can be managed through appropriate post-test driver training, regular driving practice, breathing exercises and listening to calming music.

According to the poll, the M25 is Britain's scariest motorway, described by drivers as "the road to hell".

Roundabouts and changing road standards on the A1(M) make it the UK's second worst motorway.