Authors: Zhong Zheng*,
Topics: Urban Geography, Quantitative Methods
Keywords: scaling laws, uncertainty, big data, mobile phone, travel behavior
Session Type: Paper
Start / End Time: 8:00 AM / 9:40 AM
Room: Roosevelt 3, Marriott, Exhibition Level
Presentation File: No File Uploaded
The aggregate analysis of individual trips is one of mainstreams in urban and transportation studies. Regularities of spatial distribution of individual trips have been discovered by visualization, qualitative and quantitative analysis in current studies. However, the uncertainty of spatial distributions is little discussed. This study reports the uncertainty in scaling laws of individual trips from collective mobile phone signaling data. The data recorded locations of mobile phone users for a week in the city of Guangzhou, China. The city space was divided into spatial grids (500m×500m), and the number of users in each grid was counted as spatial visitation frequency. Ranking grids by spatial visitation frequency, its scaling law was discovered as exponential decay. However, the rank of each grid is uncertain by time of day and day of week. The uncertainty of a grid’s rank is represented by a probability, that the probability of a particular rank of a grid. The uncertainty of ranks was explored by different time periods of a day and different days of a week. The ranking and uncertainty were further related to built environments, represented by density, diversity and functions. Finally a prediction model was built, which predicted the visitation frequency and its uncertainty of each spatial grid.