Mobility Behavior and Patterns using Cell-Phone Trace Data: A Case Study of Fresno, California

Abstract: This case study examines the effects of seasonal variations, the COVID-19 pandemic, and demographic characteristics as it relates to the mobility behavior of a large, suburban and rural population, of which the City and County of Fresno, California was investigated using a synthesized geographic information system (GIS) dataset originating from cell-phone trace data. Replica, a state-of-the-art Big Data GIS platform that synthesizes and aggregates input data from dozens of primary data sources, mainly from cell-phone trace data, was utilized to observe and collect data on mobility behavior for the study area. First, a comparison of travel data in Fresno County between this new dataset and traditional travel survey methods was conducted, using the Central California Household Travel Survey as a baseline for comparison. Following the data validation, the case study reviewed the effects of the COVID-19 pandemic on mobility behavior by investigating the total number of daily trips before and after the pandemic in the city of Fresno. To understand the current state of the city’s travel patterns, 6 modes of transportation (private auto, auto passenger, walking, biking, public transit, and taxi/TNC) were analyzed alongside several trip and trip taker characteristics, including trip duration, trip distance, trip purpose, age, annual income, and race in Spring 2023, the most recent dataset at the time of data collection. The final part of the case study involved a qualitative review of the temporal distribution of trip start hours by mode across a 24-hour day and the spatial distribution of biking trip origins and destinations across the city.
The findings of this case study determined that Replica is a valid data source of travel data. In the study area of Fresno, CA, the dominance of private vehicle use in a large, suburban and rural city was evident by the usage of cars for nearly 90% of all trips completed in the city, followed by walking and biking. The study found that the age range of most cyclists in Fresno, CA was 5-17, indicating the need for bike infrastructure to protect this vulnerable group. Cyclists were also found to travel nearest universities and schools, further confirming the usage of active transportation modes for commute, rather than recreation. In smaller cities with similar suburban or rural characteristics, this case study suggests that such cities, with very car-dependent populations, typically lack the infrastructure to promote other transportation modes, but targeted development in areas of lower equity or with higher numbers of travelers of active transportation modes may be effective.