- Ask a room full of road safety experts what is causing pedestrian fatalities to increase and most will admit that, well, they are not exactly sure. Every time a car hits a pedestrian, it represents the intersection of a vast number of variables. At the level of those involved, there is the question of who is distracted, reckless, drunk. Zooming out, there are factors such as the design and condition of the road, the quality (or absence) of a marked pedestrian crossing, the speed limit, the local lighting, the weight and height of the car involved. In a crash, all these variables and more converge at high speed in real-world, non-laboratory conditions that make it hard to isolate the influence of each variable.
Attempting to explain a trend – to correctly apportion blame not for one but thousands of pedestrian deaths – adds yet more layers of complexity. Economic and employment trends, the availability and quality of public transport, shifts in the age of walkers and drivers: it all matters. Disentangling the threads in a scientifically rigorous way is fiendishly difficult. “There are multiple theories about how to account for what is happening,” says Norman Garrick, a University of Connecticut professor who studies road safety. “We know something radically new is going on. But I don’t think we have an exact answer yet.”