Driving Errors Increase With Age Among Older Drivers: Blind-Spot Errors Most Common Mistake

Sample 266 volunteers aged 70 to 88

All types of driving errors increased with age.  Men fared no better than women.  Blind spot errors were the most common mistake, followed by veering across lanes and failure to use turn signals.

http://www.sciencedaily.com/releases/2011/05/110516121543.htm

Unfortunately the article does not define "blind spot error".  It has been generally thought that as one ages "looking but not seeing" incidents become increasingly common, for example, pulling out or stepping into the path of an oncoming vehicle. This has implications for speed management policies, and current legal precedents which require highway authorities, when exercising their powers, to have regard to careful and negligent road users.