, Professor, Humphrey School of Public Affairs
Researchers have shown that GPS units in smartphones can be used to identify routes taken by cyclists, including whether cyclists deviate from shortest paths to use bike lanes and other facilities. Researchers previously have not reported whether GPS tracking can be used to monitor whether and how bicyclists actually use lanes on streets (where these lanes have been provided) or other types of facilities. This researched investigated whether smartphone GPS units or enhanced GPS units could be used to track and map the location of cyclists on streets. To do so, the research team modified an open-source smartphone application (CycleTracks) and integrated it with a higher-quality external GPS unit. Cyclists then mounted the smartphone with route-tracking applications to bicycles and repeatedly rode four different routes. The routes for the field tests were chosen because each included a striped lane for bicycle traffic and they bisected a variety of built urban environments, ranging from an open location on a bridge over the Mississippi River to a narrow urban street lined by tall, multi-story office buildings. The field tests demonstrated that neither the smartphone GPS units nor the higher-quality external GPS receiver generate data accurate enough to monitor bicyclists use of bike lanes or other facilities. This lack of accuracy means that researchers interested in obtaining data about the propensity of cyclists to ride in lanes, when available, must rely on other technologies to obtain data for analyses.