Study finds pedestrians need 30 inches of space to avoid collisions

Dec. 17 (UPI) -- Pedestrians require a 30-inch buffer to avoid collisions, according to a new survey of foot traffic inside a Dutch train station.

Using overheard sensors installed in a train station in Eindhoven, Netherlands, researchers analyzed more than 5 million pedestrian movements. Their analysis revealed 9,000 pedestrian pairs on collision courses.

"About 40 pairs of these actually bumped into each other," Alessandro Corbetta, a postdoctoral researcher at the Eindhoven University of Technology, said in a news release. "The remaining pairs adapted their walkways until they were at least [55 inches] apart and were therefore able to prevent a collision."

Researchers used the video footage to train a computer model to predict the movements of pedestrians moving through a crowded space. The model could help designers better understand how spatial dimensions and the size of crowds impact the ability of pedestrians to avoid collisions.

"To build our model, we found two 'social interaction forces' that play a role: a long-distance force based on vision and a short distance force for preventing hard contacts," Corbetta said. "As an effect of these forces, people modify their current paths to prevent collisions."

Corbetta and his colleagues used their previous survey of pedestrians walking through a corridor, as well as models of fluid dynamics, to design their new simulation.

The new analysis, published this week in the journal Physical Review E, suggests there are universal patterns of pedestrian movements unaffected by the setting and space.

"We saw in our data that about one in 1,000 people would stop and invert their trajectories, to exit the tunnel or corridor from the same side as they entered it," said Federico Toschi, Eindhoven professor. "Even though they were walking alone and regardless of the motivation."

Researchers plan to continue developing more complex models to understand the movements of even denser crowds. Corbetta and Toschi are currently analyzing the results of an experiment designed to test the influence of lights on pedestrian patterns.

"We let pedestrians choose to leave our exhibit through the left or the right exit," Toschi said. "Using light with different intensity levels, we aimed at altering routing decisions in favor of one of the two exits. The first results now indicate that it does indeed appear to be possible to steer people."