Experienced as well as novice drivers need to brush up on their knowledge of the Highway Code, a new study reveals.Research carried out by price comparison website elephant.co.uk tested 3,000 motorists on the most obscure road signs and regulations and found those over 60 and aged between 17 and 21 did least well. Brian Martin, managing director of the firm said it was interesting to see that the most extreme age groups failed to make the grade. "Perhaps the over 60s have forgotten what they were taught and maybe the younger drivers simply weren't paying enough attention when they were learning," he added. Mr Martin also noted that those aged between 40 and 50 would not have sat the driving theory test which is compulsory today, but recorded the best results.Earlier this month, Rias stated that driving without adequate insurance cover is "unlawful and ill-advised", and costs innocent British drivers and average of £30 every year on their premium.