Understanding How the Built Environment Around TTA Stops Affects Ridership: A Study for Triangle Transit Authority

This study determines the characteristics of urban development that related to Triangle Transit Authority (TTA) bus ridership levels in the Triangle region of North Carolina. While transit offers an alternative to driving, development patterns around stations must support transit use if significant ridership is desired. By analyzing the built environment – including the design, density, diversity, and destinations around bus stops – this study offers local decision makers ideas to improve the planning of these areas. The predominately suburban form of the Triangle region raises the question of how well previous findings apply to this area. As a southern area with mostly postwar growth, the Triangle’s urban form is distinct because it contains several city centers which surround a low-density research park. Furthermore, the Triangle relies on bus-based services to provide regional transit connectivity – different from previous studies that relate urban form to transit around rail service. It is relevant to examine the unique features of development and transit in the Triangle to assess their relationship more accurately, offering new information useful to municipalities, counties and transit operators in the area. Using a proportional random sample of both ‘urban’ and ‘not urban’ stops, the authors collected data about the built environment around 148 bus stops in the Triangle area. In addition, they compiled secondary GIS data and transit service supply information for each stop. With this data, they used regression analysis to relate TTA boardings and alightings to the characteristics of each stop and its surroundings. The authors' results suggest total boardings and alightings have a significant relationship with bus stop amenities, quantity of destinations, building and site design, and number of buses serving a stop. The pedestrian and bicycle environment was also relevant. The amount of neighborhood features and the intersection density were significant, but had an impact on ridership contrary to expectations. While their results cannot be necessarily considered the cause of higher or lower transit use, their findings maintain the importance of a built environment that supports, and perhaps encourages, transit use. As a result, they conclude that policies which create a transit supportive environment, including provisions for bus stop shelters, mixed-use developments, and smaller setbacks, would prove fruitful strategies for developers, transportation, and land use planners in the area. Although their study focused on the Research Triangle area, these results may also be useful to similar areas relying on bus transit to provide regional public transportation connectivity.