A poll of nearly 1,500 drivers conducted on behalf of the IAM suggests that younger drivers are the group most likely not to be concentrating while driving.
Overall, the poll of nearly 1,500 drivers suggests that only 60% of drivers are concentrating when they are behind the wheel.
Among respondents aged 18-24 years, the worst performing group, the figure fell to 50%, followed closely by those aged 24-34 years (47%).
The survey suggests that older drivers are much less likely to lose concentration while driving. 73% of respondents aged over 65 years said they concentrate when driving all of the time, while a further 26% said that they concentrate most of the time.
The most common reasons given for not concentrating were daydreaming (24%), stress (22%), thinking about what you will be doing when you arrive, and thinking about family, friends and personal relationships (both 21%).
Simon Best, IAM chief executive, said: “Not concentrating is a key cause of crashes yet it is not borne out in statistics because drivers rarely admit to it in police reports or on insurance forms.
“These results reconfirm stereotypes surrounding younger drivers and the ease with which they can be distracted from staying safe. The key is to build up as wide a range of experiences as possible as you learn and to look upon your driving as a skill that needs continuous improvement.”