Failing to indicate causes ‘millions of crashes per year’, according to a Society of Automotive Engineers (SAE) report.The US-based study shows that the effects of failing to indicate could be worse than ‘distracted driving’ – using a mobile phone behind the wheel.The study watched 12,000 vehicles as they turned or changed lanes, and noted the rate of those who used their indicators. It showed that a staggering 48% of drivers didn’t bother indicating when changing lanes, and 25% didn’t when turning.