AS many as three quarters of drivers don't know the basic rules of the road, according to new research released by Brake, the road safety charity.

A survey of over 1,000 drivers, also revealed that more than a fifth of drivers hadn't read the Highway Code in over a decade.

Brake is urging drivers to pick up the phone and buy the Highway Code on CD-ROM.

A Brake-endorsed version of the new Interactive Highway Code, developed by Interactive Driving Systems, can be obtained by calling the charity on 01484 559909 for £6.99.

The survey made the following key findings:

*Only half of drivers claimed to have an up to date copy of the Highway Code.

*More than a fifth (22.5%) of drivers had not read the Highway Code for over ten years.

*74 per cent of drivers did not know when the Highway Code was last revised, and therefore may not be up to be up to date with the current rules of the road.

* More than 20 drivers had never read the Highway Code.

* 61 per cent of drivers cover more than 10,000 miles per annum.

* Nearly 30 per cent of drivers had read the Highway Code to pass their driving test - but then would only read it again for work (15.7%), after a specific incident (11.3%) or when their children were learning to drive (8%). In total there were over 600 separate reasons given why it may be useful to read the Highway Code.

* Over 50 per cent of drivers used their cars for work, or to get to and from the workplace.

This suggests that employers have a duty of care to ensure that employees are given up to date copies of the Highway Code as a minimum standard.

Mary Williams OBE, Chief Executive of Brake said: "This research shows a shocking level of ignorance about the rules of the road.

"If people who drive for a living aren't up to date with the Highway Code, this raises serious concerns about the rest of the driving population.

"We would urge drivers to make sure they read the Highway Code because it could save a life."

Used-car buyers tempted by frugal diesels could have to do up to 56,373 miles before reaping the financial benefit of the fuel savings they believe are on offer, according to new research by used-car price experts WiseBuyer's.

It is claimed the survey explodes the myth that choosing a diesel automatically drives down the cost of motoring compared with a petrol alternative.

On average, the cost of buying a used diesel is between eight to 12 per cent higher than its petrol equivalent.

And service costs for some diesel models are higher, too.

As a result, owners need to complete thousands of miles before they break even.

WiseBuyer's data shows that a 12-month-old Ford Focus 1.8 TDCi LX typically costs £1,150 more on the forecourt than its 1.6 LX petrol alternative.

Although the former records an average 53.3mpg compared with 40.9mpg for the petrol version, the actual fuel cost saving is only 2.04 pence per mile travelled.

So owners would need to complete 56,373 miles before fuel savings recoup the extra cost of buying a diesel.

Even a small city car, the Volkswagen Lupo 1.4 TDi PD Sport, which costs just £350 more than its 1.4 Sport petrol cousin, needs 14,286 miles to be covered before you start benefiting from the more economical diesel engine.

Purchasing a seven-seater Ford Galaxy 1.9 TDi Zetec diesel would demand the owner completing 43,237 miles before matching the £1,950 cheaper 2.3 Zetec petrol equivalent.

Nic Barfield, editor of WiseBuyer's, says that too few motorists hunting for a used car take into consideration the true cost of buying a diesel.

"For someone who only does 10,000 miles a year, a diesel may not be the best option.

As the research shows, it could take up to five years of average motoring to start feeling the financial benefit of the fuel savings."