It's also not uncommon to see "Children at Play" signs in the presence of 35 mph speed-limit signs, which is roughly akin to trying to put out fire with gasoline. It's not simply that fatality risks begin to soar at impact speeds of more than 20 mph, but that, as a study by John Wann and colleagues at Royal Holloway University in London has suggested, children, until well into their teens, are unable to detect during a normal crossing of the street the approaching speed and distance of cars above a threshold—also 20 mph. This study adds legitimacy to the increasingly popular idea, as introduced in the U.K. in 1991, that residential areas be designated as 20 mph zones. (Research by the Transport Research Laboratory has found, among other things, a 60 percent crash reduction during the "after" period in 20 mph zones.)
It is, of course, no secret that children are risky pedestrians. "Children are particularly vulnerable to pedestrian death because they are exposed to traffic threats that exceed their cognitive, developmental, behavioral, physical and sensory abilities," reads a typical child safety document. "Children are impulsive and have difficulty judging speed, spatial relations, and distance."
This is all true, and well and good, but it overlooks one thing: The same could be said about many adult drivers, the ones putting those children at risk. As is often the case in driving, when we meet the enemy, it is us. You want difficulty in judging spatial relations? Consider the research, by Dennis Shaffer, that showed people reporting 10-foot-long highway stripes to be two feet long. You want difficulty estimating speed? Consider this study, which found drivers underestimating their speed in the presence of children by upwards of 50 percent. You want exceeded sensory abilities? Consider the widespread phenomenon of "overdriving" one's headlights. You want trouble estimating distance? Ask any driver how many feet they'll need to stop, driving at 65 mph. You want impulsive? Who's reaching across the seat for that buzzing BlackBerry? Driving, developmentally, turns us into children.
But it's easier to blame the victim and to say the child trying to cross the road, on which cars were moving faster than they should, impulsively darted into traffic. As a paper in Injury Prevention noted, however, "drivers who hit a child pedestrian were more likely to have had a prior citation, more citations, more safety violations, a suspended or revoked license, or more negligent operator points than drivers who did not hit a child pedestrian in the study period." Not to mention the many cases (to cite just one recent example) of children struck by drivers when they weren't even on the road, when they weren't "playing," but simply walking.
"Children at Play" signs may not be doing any good, but simply removing them isn't likely to do much more. What we need is lower speeds, and a more compelling way of achieving those speeds than signs that everyone has seen, and no one seems to mind.