By Eric Jaffe, November 27, 2013
If you want to understand why people use a certain transit system, it makes sense to start with the system itself. Frequency, access, and any other service qualities that make riding as convenient as driving will help. Whether or not the way a city is designed and built nudges people toward the system — via residential density and street design, for instance — matters, too.
But as we've pointed out in the past, there's a psychological component to riding transit that's easy for city officials and planners to overlook. Fact is, we're not all completely rational about our travel decisions. The perceptions that people have about public transportation, substantiated or not, are powerful enough to attract or repel them.
Most attempts to evaluate transit success focus on one of these areas or another. A research team led by planner Steven Spears of UC-Irvine recently made what they believe is the first documented effort to include all these elements — built and behavioral alike — into a single assessment. Their work identifies two basic but vastly underappreciated factors in transit use: general attitude toward transit, and concerns about personal safety.
Spears and collaborators analyzed transit service and the built environment in several neighborhoods in South Los Angeles (below). Factors like neighborhood walkability, nearby traffic volume, land use, station accessibility, rush-hour service levels, job access, and others were all considered.
Courtesy Spears, et al. (2013). Illuminating the unseen in transit use: A framework for examining the effect of attitudes and perceptions on travel behavior. Transportation Research Part A: Policy and Practice, 58, 40-53.
The researchers also conducted in-depth travel surveys of 279 area residents on their perceptions of the transit experience. They took into account seven potential behavioral factors: crowding, attitude toward transit, social norms, perceived travel control, environmental concern, safety concern, and neighborhood amenities.
Some of what the researchers found with regard to the city design shouldn't come as a surprise. Street connectivity was a significant predictor of transit ridership in the area. As the number of intersections within a half mile of a resident's home went up, so did the likelihood that person rode transit. Simply put, neighborhood walkability promotes transit use.
Of the behavioral factors in play, only preconceived attitudes and safety concerns had significant impacts on whether or not a person rode mass transit. The warmer a person's attitude toward transit, the more likely that person was to ride. At the same time, the less safe a person felt about riding or being in a station, the less likely that person was to use the system.
That conclusion doesn't seem earth-shattering on its own, of course. But what's critical to recognize is that these two cognitive factors remained significant predictors of transit use even after the researchers controlled for quality of service and characteristics of the built environment. In other words, mere perceptions about transit — some of them irrational and unjustifiable — can influence someone's decision to ride over and above all other factors.
Spears and collaborators conclude:
Overall, our results indicate that attitudes and perceptions of the built environment and transit system attributes appear to play a significant role in transit use that is independent of objectively measured attributes such as level of service, employment accessibility, or security.Despite its limitations (most notably, too few participants), the study should compel others to consider psychological components in their transit evaluations. Beyond that, it suggests that campaigns to target common misperceptions of transit — that it's inconvenient, or that it's unsafe — may be as important in some places as improving service itself. The first step toward helping city residents make reasonable transportation decisions is recognizing that sometimes they don't.