This research focuses on utilizing the typically overlooked taxi manifest data to analyze taxi operations with respect to transit, and also presents alternative uses for the data in transportation planning. Taxi travel characteristics are explored for Arlington, Virginia, a county containing both urban and suburban qualities. Previous research contends that manifest data can provide valuable quantitative descriptors of taxi travel. This thesis attempts to describe taxi travel by quantifying trip characteristics; the shortcomings of using manifest data are discussed and the results are reported. The taxi operations results are then compared for weekend and weekday travel and also for airport and non-airport bound travel. Several key differences between these groups of taxi trips are discussed. Next, an investigation of the relationship between mass transit facilities and taxi travel is conducted. Because taxis provide a complementary yet competing public transportation service to mass transit, it is hypothesized that examining the proximity to transit options and the timing of taxi trips can provide insight to the perceived gaps in mass transit services. However, the data show that simply examining geographic or temporal characteristics of taxi trips does not define clear relationships between transit facilities and taxi use. Instead, the results suggest that other variables such as land use and vehicle access may hold a greater influence over the generation of taxi trips. Despite the difficulty in using manifest data to determine gaps in transit, the data collected by taxi regulators could have numerous applications for planners. Possible applications for the type of taxi data used in this research are explored and a potential data flow for agencies is proposed. / Master of Science