From the looks of today’s subway map, transferring amongst trains at Fulton St. appears to be a piece of cake while traversing the distance from the 2 or 3 to the A or C, let alone the E, at Park Place/Chambers St. would require a very long walk. There might be some truth to the distance, but that up-and-down trip between trains at Fulton St. is hardly convenient. Thus, enter the “subway map effect.”

We last heard of the subway map effect in May of 2011 when NYU Professor Zhan Guo released a study on map design. By examining London’s schematic map, Guo determined that map design can impact travel choices to a rather extreme degree. Commuters in London were willing to travel inefficiently because they believed making a transfer would get them closer to their destinations than walking would. The distortions of the schematic map rule how otherwise-sophisticated travelers plan their rides.

So what happens when you start tweaking the map design? Can transit agencies control behavior by adjusting design? Perhaps by making a transfer look shorter, transit planners can siphon riders into a less trafficked area. Guo now plans to find out. He spoke to Jessica Gross for a piece on The Atlantic Cities about his current research, and here’s how Gross described it:

Which leads to Guo’s big question: “Can we change the map in order to change people’s behavior?” If we believe maps over our own knowledge, and we do, the answer is likely yes. In a new study of D.C.’s Metrorail system, Guo is measuring the difference. He’s collaborated with Wyman to produce three variations on the Metro map, all of which increase the apparent length of the Blue and Orange Lines at the point that they cross the Potomac River. One increases to the west, one to the north, and one in both directions. Comparing reactions to these maps to the current one, and to a real geographic map, will help Guo better understand how both route length and directionality can factor into passengers’ decisions. Can Guo and Wyman encourage people, through design alone, to transfer to the Yellow Line over the river instead of staying on the Blue? This isn’t just a matter of intellectual interest: The Rosslyn tunnel is overcrowded, so rerouting some human traffic would make a difference. “Even if you can switch one or two percent of passengers from the Blue to the Yellow Line, that’s a big success, because the cost is zero,” Guo says. That is, altering infrastructure is expensive, and since many transit agencies, including WMATA, face big budget shortfalls, it’s often difficult, if not impossible. But changing a map—making this crowded line look longer and less convenient, or replacing that complex-looking transfer with a dot—could change usage patterns practically for free. Mapmakers could nudge us to not only use less crowded lines, but also get out and walk, transfer at less trafficked stations, or even use alternate transit systems.

For a bit more, check out this abstract on Guo’s own site. On the surface, it makes sense. We use a subway map for visual cues to help us plan our journeys. If we’re not familiar with a system, we’ll seek out the map for assistance.

What intrigues me about Guo’s research though are the long-term implications. Will riders continue to follow the cues from the map if they know one route is shorter than the other even if it doesn’t appear that way on the subway map? New York’s system doesn’t have quite the same number of transfers as some others; you can thank the City, the BMT and the IRT for that. But it has enough. We’ll have to check back in with Guo once he’s wrapped up his investigation of Washington. For now, it’s food for thought.