Urban heartbeats (daily cycle of public transport intensity)

Abstract

Main focus is put on the daily cycle of public transport intensity. In the city, commuting between places of housing and places of work one of the most important types of recurring organized spatial interactions. This is reflected also on the public transport which has tendency of creating communities as a reaction to demand. This feature of public transport in a city can be clearly identified through network analysis. Network approach recently developed in theoretical physics and related disciplines is still a promising direction of research also in the case of urban transportation studies. We use public transport system in a usual European city, a representative day in Bratislava, to demonstrate that it behaves systematically along the daily cycle in response to changing demand. Even through only basic description of data was calculated, the daytime rhythm, which we call the urban heartbeat, can be clearly recognized in the network structure. Though, the difference between intensity is clearly expressed, only the difference between night and day seems to have bigger statistical difference.