Location as a measure refers to knowledge of the exact or approximate geographic placement of a vehicle or user within the transportation network at a specific point in time. Knowing where vehicles are located is a critical element in the analysis of travel behavior and demand. In the context of urban and metropolitan freight movement, location information can aid in studying parking behavior, land use, use of commercial facilities such as distribution centers, loading zones, as well as vehicle ownership and commodity flow.
Data sources that help identify the location of commercial vehicles can be characterized based on latency, i.e. the amount of time that elapses between when a vehicle’s location is recorded, and when it becomes known to a decision-maker. In the case of real-time data (low latency), the geographic position of a vehicle is reported by devices such as a GPS device, or a smartphone at a very high frequency and this information is made available for use almost instantaneously. On the other hand, vehicles’ location information over longer periods of time (days, weeks, etc.) can be obtained from archival databases that use roadside devices or in-pavement sensors to collect data.
The following data sources can help determine commercial vehicle location.