Why People Are Terrible at Navigating Cities
People are always looking for the shortest route to reach somewhere — think coffee shops, university, work. Turns out, we may not be programmed to take the quickest route while navigating within cities.
According to a study published in Nature Computational Science this week, people are more likely to continue walking down the direction they are facing — irrespective of whether that’s the shortest way. Researchers called this following the “pointiest path,” one that’s pointing the way on our eye line. The findings put together why people choose certain paths while driving or walking, over others.
The researchers, led by M.I.T., tapped into the mobile data of 14,000 people, examining how they traveled around Boston, Cambridge, and San Francisco for a year. Out of the web of 550,000 pathways, pedestrians chose to travel the direction they were facing as much as possible.
For instance, if one is walking towards North but their destination is towards the West, they are more likely to walk straight instead of turning left immediately — taking the longer route. Or, if the internet were a fictional city, the shortest route to finding what happens in Dune is a Google search. But people may end up first searching Timothée Chalamet, going through his filmography, finding the entry for Dune, and then reaching their metaphorical destination.
The same is also evident in round trips. Carlo Ratti, a computer scientist at Paolo Santi of M.I.T., found that he took two different routes between his home and office; one, on the way to the place, and a slightly different one on the way back. Even though the former was shorter than the latter, it didn’t change the way he traveled.
“Instead of calculating minimal distances, we found that the most predictive model was not one that found the shortest path, but instead one that tried to minimize angular displacement – pointing directly toward the destination as much as possible, even if traveling at larger angles would actually be more efficient,” Ratti, who was part of the study, said.
The researchers argue this is because our brains prioritize other tasks, like watching out for street signals or cars, at the cost of the quickest navigation. “There appears to be a trade-off that allows computational power in our brain to be used for other things,” Ratti added. 30,000 years ago it was to avoid a lion, and “now, to avoid a perilous SUV.”
Related on The Swaddle:
Researchers explain this mapping tendency as “vector-based navigation.” It doesn’t always come with the promise of rationality and logic. So while humans may have evolved to avoid dangers like lions and cars, it doesn’t mean we have found the most efficient way to get around cities. “This is because evolution doesn’t seek optimization, but ‘sure, OK, that works, I’m not dead’ – something that has been dubbed ‘survival of the adequate,'” as ScienceDaily noted. It doesn’t matter if the shortest distance between two points is a straight line; what matters is where the person is facing.
Vector-based navigation is something animals do too. Researchers have explored the travel paths of crows, among others, observing animals make direct journeys between different places even if the route is new or longer.
“Computers are perfectly rational. They do exactly what the code tells them to do. Brains, on the other hand, achieve a ‘bounded rationality’ of ‘good enoughs’ and necessary compromises. As these two distinct entities become increasingly entangled and collide – on Google Maps, Facebook, or a self-driving car – it’s important to remember how they are different from each other,” Ratti wrote for The Conversation.
People may no longer be walking alone or navigating based on their directions. The findings have implications on how urban streets are designed, how friendly they are to pedestrians, and how can technology better compute these behavioral tendencies.
As Ratti noted, “The more people become wedded to technology, the more important it becomes to make technologies that accommodate human irrationalities and idiosyncrasies.”