Taxicab availability: Empirical study of Kunshan, China

Because of the popularity and necessity of taxicabs, taxicab-related research has received increasing attention over the past decade. However, few studies have highlighted the value of taxicabs as an important component of public transportation systems, and the measurement and evaluation of taxicab systems have been largely missing in the previous literature. Two measures, from a demand and supply perspective, intuitively can serve as the measures for evaluating taxicab service performance, including loading and availability. Since the concept of taxicab availability has not been clearly defined in previous research, this study proposes a new concept of taxicab availability based on the concept of transit availability. Four taxicab availabilities—namely, spatial, temporal, capacity, and information availability—are further defined and introduced. The study used a large amount of taxicab GPS-based data to measure these availabilities. A framework is proposed to investigate statistically whether there are mathematical patterns behind loading and availability. The results show that patterns can be found and mathematically described, and statistically accurate and reliable taxicab information can be produced based on the patterns. Two presentation aids were selected to present the information: taxicab timetables produced for the general public and loading and availability heat maps produced for decision makers. The research provides detailed insight into taxicab system performance. The contributions of this research are to provide (a) guidelines for evaluating system performance in a city or region and (b) taxicab timetables for the general public.