If you had to guess, which of these road signs do you think would provoke the biggest reaction from a driver?

The answer, say the authors of a new study on driver reaction times, is the one on the right. 

The reasoning is actually fairly straightforward. An image of a faster-moving stick figure creates a greater sense of risk in the driver’s brain: if the images look like they might be about to run out in front of you, your reactions are faster, so you’re quicker to reduce speed. The ambling figures in the signs on the left – real road signs from the US and Poland – don’t create the same sense of urgency. 

In fact, the project’s researchers, from the University of Michigan and Brigham Young University, found that, in simulations, drivers responded around 50 milliseconds faster to the sign on the right than to that on the left. That’s only 0.05 of a second, but if you’re travelling at 60mph it translates as 4.4 feet: that could be the difference between hitting someone, and, well, not. 

The team also carried out a second experiment with eye tracking software, which found that signs which showed greater movement attracted the drivers’ attention earlier, and maintained it for longer. 

Both experiments convinced the researchers that these “high dynamism” signs could help cut road deaths, as they grab drivers’ attention and speed up response times. Now it’s up to road agencies to take their advice.