There’s nothing quite like a stroll with environmental psychologist Colin Ellard to help you understand a city in a new light. Whenever he rolls into town, I get pretty excited—mostly because I know he’ll probably indulge me, and come play geek with me in traffic.
A good friend of the Lab by now, Colin has been along every step (and city) of the way since the Lab first opened in New York. He’s been running an experiment called Testing, Testing! that uses various methods and pieces of equipment to measure people’s emotional, mental, and physiological reactions to different types of urban environments. Along with his technological devices, he also comes equipped with an experimental sense of fun and curiosity about cities.
That is why I was able to talk him into a visit to Kala Nagar junction.
Kala Nagar Junction is one of Mumbai’s nastiest traffic junctions—see my description of the place when the Lab launched a competition for its redesign. The first time I went there and stood amid the chaos and noise, Colin was the first person who popped into my mind. Previous experiments he did with us in New York showed that large zebra crossings and chaotic, loud environments spiked our levels of “arousal” (the technical term environmental psychologists use to describe a general feeling of activation, excitement, and engagement) as measured by his sensor cuffs. If that was the case, I thought, what would a walk through a place like Kala Nagar junction do? Could our reactions give us hints about how the junction could be better designed?
The results were nothing short of fascinating and, yes, offered some incredible insights into how design influences our bodies and minds.
Below is a map of the walk that Colin and I did.
For those unfamiliar with Mumbai—and with this particular use of Google Earth maps—a quick rundown:
The walk began at a railway station in Bandra, one of Mumbai’s northern suburbs. From there, we walked 1.2 kilometers along a skywalk (a raised pedestrian walkway), across the major roads of the junction before we descended into it. Once on the ground, we looped our way around the junction, making a couple stops underneath the flyover (that’s the big messy knot in the center of the image on the left) and in an adjacent park (where the little tree symbol is) before walking on ground level along the road back to the station.
The green line you see is actually a contoured representation of my rising and falling arousal levels, which, zoomed in from the side, look a little more like this, with the peaks representing high levels of arousal and the valleys low levels:
This map shows a few very interesting things. The first and most obvious one is that my overall arousal levels rise significantly—by about one third—as soon as I enter the area of the junction and even before I descend down into it, as seen here:
Given the noise and chaos of the junction, this isn’t particularly surprising. More interesting, though, is where the highest peaks on the map lie.
Two of the major peaks occur at a time when we were about to cross a road:
Though we crossed several roads during the course of our walk, the two that caused the peaks had something in common: they were unregulated crossings with no lights where, instead of waiting for the light to turn red, and to walk across the road when traffic is stopped, the pedestrian is forced to watch for a break in traffic, and dart across. Interestingly, the peaks actually occurred before we crossed the road. Once we identified the break and made a run for it, my body actually relaxed a little. According to Colin, this is quite understandable: it is the anticipation of the crossing, and my body ramping up to do something challenging, that really causes the most stress.
I was surprised by the location where the third major peak occurred: a bench in the relatively quiet, well-manicured park adjacent to the junction. Colin was less surprised by this. “These sensors can’t differentiate between good and bad arousal. So when people go into spaces that they actually like, their values increase as well,” he told me. Indicators such as blood pressure could help determine the type of arousal being displayed by the cuffs, but this is much more difficult to measure in a mobile setting.
Self-assessment plays a big role in determining the different types of arousal. When participants do their walks for the Testing, Testing experiment, he said, they often show higher levels of arousal in green spaces. Their self-report distinguishes that reaction from high levels generated elsewhere: they report feeling happy, instead of feeling, say, stressed. This is likely what happened when I was sitting in the park.
The final fascinating note is that while walking to and from the junction, there appears to be little difference in my arousal levels while walking on the skywalk versus walking on the road. In this image below, you can trace my walk to the junction on the skywalk (the lower line), and back along the road (the upper line). There is almost no difference.
Even when crossing the major street of the junction—the one that caused my peak in anticipation of crossing—my arousal levels standing on the skywalk over traffic are barely lower than when I am physically darting through it.
So while a skywalk may reduce the stressful experience of waiting to cross a road, and may keep us safer from rogue drivers, it does not necessarily mitigate the effect that the noise and chaos of traffic has on us mentally and physically.
What does all this mean for us? Well, that all depends on how much time you spend at places like Kala Nagar junction.
According to Colin, it’s a perfectly good and natural thing that we peak at scary intersections like I did; it’s what keeps us from doing something stupid like walking unknowingly into traffic. What makes it bad, however, is if we live in a situation where we’re constantly called on to muster up those kinds of levels of arousal. “Over time, that’s very taxing on the body. Ideally, you want to live in circumstances where that level of arousal is going up and down nicely, with regularity. You don’t always want it to be high, you don’t always want it to be low, you want there to be lots of variability,” Colin said.
“It’s a matter of keeping you physiologically healthy. If it’s always low, then what that means is there’s very little stimulation—stimulation for your brain, stimulation for your body—and we know that that doesn’t bode well for things like cognitive abilities. But if it’s constantly high, then you’re constantly secreting high levels of things like cortisol [the stress hormone] and that has effects on . . . cardiovascular health and many other things. The idea is to have your system be challenged. . . but not to be overtaxed.”