Almost half of Britain's drivers would fail their test if they were to re-sit it, thanks to the bad habits motorists pick up over time.
The research by What Car? magazine suggests that 15m of the UK's 33m drivers would not be successful in gaining a license if they were forced to retake their test.
The magazine carried out research on a sample group of 20 drivers aged between 19 and 70, making them take a mock test. Of those, only 11 were successful, with eight committing a serious fault that resulted in an immediate fail.
In total, the sample drivers committed a total of 277 faults – an average of just under 14 each. The driving test allows a candidate to make 15 minor faults and still pass.
The biggest error made was a lack of observation, with 30 percent guilty of not looking properly. This was followed by speeding and moving away unsafely. Another 10 percent of faults were given for inadequate control of the car, while another 10 percent were for incorrect signalling.