DRIVERS are losing their patience with "unsafe" potholed roads, a Government-commissioned study on the country's key arteries has found.

Satisfaction with the state of Scotland's busiest roads has dipped significantly over the past six years, the research reveals.

Only 40% of motorists said they were happy with the condition of the trunk road and motorway network, while the same survey results from 2006 – first published in 2007 – found just over half were satisfied.

The growing disquiet has coincided with a gradual deterioration in the condition of Scotland's 2000 miles of trunk roads, which carry 37% of the country's traffic.

It echoes Audit Scotland findings which showed that although they were in better condition than council-owned roads, Scotland's major routes managed by the Government had deteriorated at a faster rate, and more than one-fifth were in an unacceptable condition.

The findings revealed today show three-quarters of complaints related to potholes, up from 62% when the question was asked in 2006.

However, the documents showed overall satisfaction levels improved since 2011, when motorists were still struggling with the consequences of two severe winters, which wreaked havoc on road surfaces and left only 29% of drivers satisfied.

The results are based on an Ipsos Mori survey of 2001 drivers carried out earlier this year.

Half of the respondents said they were dissatisfied with road surfaces. Of that group, half said they usually or always experienced defects that make them feel unsafe.

Satisfaction with winter maintenance on the trunk road network has increased since 2011, and around half (52%) of respondents were satisfied with the promptness with which roads were gritted compared with 39% in 2011. A similar proportion were satisfied with promptness with which roads were cleared compared with 36% in 2011.

Peter Rodger, head of driving standards at the Institute of Advanced Motoring, said the figures were concerning. He said: "It is not good news that a very large proportion of people are not satisfied.

"It is particularly concerning that such a high proportion feel they have had safety issues as a consequence of road conditions."

Mr Rodger added: "I note the Scottish Government are saying things are getting better, but with this kind of results they need to keep on getting better. A good infrastructure is important for road safety."

The Scottish Government welcomed the survey, highlighting the improvement in drivers' experiences. Transport Minister Keith Brown said: "These results are encouraging and later this week we are launching our winter programme with the media to build greater public awareness of what this service means for Scotland's road users."

l Customers will benefit from lower fuel costs today after some of the country's biggest supermarkets announced price cuts. Asda, Tesco and Morrisons pledged to cut up to 3p a litre off the price of both unleaded and diesel.

The cost of oil has fallen in the past 10 days with Brent crude sliding 6% to around $110 a barrel.