Traffic fatalities were down 20 percent this year from last year, but this week’s report by the city’s Health Department didn’t contain entirely positive news: From 2005 to 2009, a total of 770 pedestrians have been killed, more than half the number of total traffic deaths (1,467) in the five boroughs. Of those pedestrians, a large portion of them were at intersections with traffic signals. In those cases, 38 percent of the deaths were due to people crossing in the crosswalk but without the proper crossing signal. Fifteen percent were pedestrians walking outside the crosswalk. But a whopping 45 percent of pedestrian deaths in marked intersections were people who were doing the right thing: walking when there was a “Walk” signal. Does this mean you should stop following the signals? No — it means that the vast majority of people are in crosswalks when signaled to cross, and therefore by sheer volume more incidents occur at that time. But still, this is a classic depressing New York statistic: Of all types of pedestrians, the group in which most people were killed was the one where everyone followed the rules.