Harnessing the Power of Peer Pressure Could Help Reduce Traffic

People are more likely to carpool if they think their peers are doing it too

Thomas Roepke/Corbis

Much like frustrating gridlocked city streets and clogged, slow-moving highways… people are slow to get going when it comes to shifting their driving habits. But CityLab’s Eric Jaffe explains that there might be what he calls an “underrated approach” to getting traffic moving again—the power of peer pressure.

Jaffe cites a recent study from a group of Canadian researchers who asked how social norms impact the use of private vehicles. After recruiting 78 regular commuters, researchers asked them to keep a journal of their journeys. They provided participants information on alternative modes of transportation, like carpooling and mass transit and asked them to reduce their vehicle use by 25 percent. Jaffee explains the details of how this went down:

Here’s the twist: not everyone was asked the same way. One group, a control, was simply given the information on alternative modes and nothing more. Another group received a peer pressure message with “low” power, telling them “only” 4 percent of other campus commuters had given up the single-occupancy drive. A third group got the “high” peer pressure push—told that about one in four commuters had switched from a car to a more sustainable travel mode.

But it was in the results where the rubber hit the road: the team found that the higher the peer pressure, the lower the use of private vehicles. In fact, commuters who received the most peer pressure reduced their use of private vehicles five times more than those in the control group. There could have been some self-selection bias at play, Jaffe notes, as participants more interested in alternative forms of transportation might have decided to do the study. But it's possible that comparing people to one another could be a powerful way to impact city driving patterns.

Since the study seems to show that peer pressure could be effective in reducing single-vehicle use and, eventually commute times, does traffic-related public shame play into city's future plans? Maybe, but maybe not — rather than investing in wider roads or public education campaigns, some communities like this Florida city are opting for a different approach. Given more congested roads, they’re opting to do nothing — and hope that people get so frustrated, they change how they commute.