The IAM found 12 experienced drivers who were prepared to undertake a mini-driving test again and discover if they would pass their test if they had to take it in today’s conditions.

Going by the criteria of the IAM’s qualified assessors on the day, just 50% (six of the 12 who took part) would pass if they took it again today.

The exercise was undertaken to see if the UK’s driving test, which marks its 80th anniversary this year, still meets its objective in allowing only the most competent drivers onto the road.

Auto Express has revealed that the pass rate when the test was introduced in 1935 was 63% – today it has fallen to 47%.

Failing to use mirrors enough, overspeeding and underuse of signals were typical of bad habits picked up by the IAM’s volunteers on the day of the experiment.

Of the 12 volunteers, seven had undergone advanced driver training with the IAM. Of those, six passed the mini test. And of the five who had had no advanced tuition, just one passed.

Sarah Sillars, IAM chief executive officer, said: “The results of our joint experiment were very interesting. It shows that keeping your skills topped up and knowledge of the Highway Code current is crucial in making safer drivers and riders.

“Road skills cannot be allowed to lapse. Keeping your skills current through advanced tuition and other proven methods can only be a benefit to everyone who uses our roads.”