AbstractWith the growth of a city’s economy, neighboring cities are gradually integrated to form an urban agglomeration. As travel activities driven by various travel demands frequently take place within an urban agglomeration, it is essential to understand the travel demand between cities and improve the intercity transportation system, which promotes the coordinated development of cities in an urban agglomeration. This paper presents our investigation of the travel demand characteristics of urban agglomeration cities. The Beijing-Tianjin-Hebei area and its passenger flows between transportation hubs in the different cities, which are part of a typical urban agglomeration in China and representative travel demand, are taken as the empirical study objects. First, we introduce a method to extract trip data using mobile phone call detail record (CDR) data, which carry rich geographical information on travelers and has been extensively used in recent transportation research. Based on trip data, directed weighted travel demand networks were constructed, with the nodes representing the transportation hubs and the edges representing passenger flows. The results showed that edge weights can be characterized by power-law distribution, which reveals the phenomenon that most passenger flows are concentrated among a few hubs, implying unbalanced travel demand in the urban agglomeration. Our empirical findings contribute to a method for applying large-scale location-based data to extract human mobility information and to understanding the nature of travel demand on the scale of an urban agglomeration. They also provide guidance to government agencies in developing appropriate transportation policies and enhancing infrastructure in the urban agglomeration.