It turns out that a lot of the problem is turning — a third of all fatal accidents involving seniors take place at intersections, according to the Insurance Institute for Highway Safety. Some 35 percent of all of their traffic violations occur because of failure to yield, and one in four are due to improper left turns. Neglecting to stop at a traffic signal is the other most common issue. An AAA/Carnegie Mellon study points out that accident fatality rates climb sharply after age 65. And, eek, look at this: For drivers 75 to 84, the rate of traffic deaths per 100 million miles driven is about the same as it is with teen drivers. For 85 and over, the death rate is four times that of teens. Here are 10 telltale signs that an older driver in your family should probably surrender the keys.