The Parliamentary Advisory Council for Transport Safety (PACTS) has published a report summarising research into how some cognitive and physical impairments increase on road risk.
"It is reasonable to expect that every road vehicle operator, whether driver or rider, should be fit to drive. “Fitness” can be defined as being physically and mentally fit to hold a licence and being unimpaired whenever driving or riding. This report summarises the research evidence on how the various sources of lack of fitness are related to the risk of being involved in a crash."
Click here for more information abut the report.