Speed refers to the rate of change in a vehicle’s location, as it moves through a transportation network. Information about the speed of vehicles at specific locations and times is an important insight for understanding the performance of the transportation network. For example, in areas where traffic frequently moves slower than posted limits, this relatively low speed may be a symptom of traffic congestion or poor infrastructure design, and this undesired slow speed can have negative impacts on the efficient movement of both passenger vehicles and trucks. Measuring the average travel speed of commercial vehicles can provide information for traffic flow management strategies, road network performance analysis, and studies of travel delay and congestion. These types of evaluations can provide some of the insights necessary to understand or address the freight challenges of congestion, last-mile access, and land use conflicts.
Speed measurement methods and devices vary in ease of use and implementation as well as their level of accuracy. While some methods such as Global Navigation Satellite System (GNSS), calculate the speed of vehicle movement in real-time, other methods such as wireless address matching, merely estimate an average speed of travel between two measuring points. As a result, some simple speed data sources like wireless address matching are unsuited for applications that require finely-detailed information on the movement of vehicles.
The following list presents the different data categories used in determining commercial vehicle speed and each item on the list will guide the users to a brief discussion about the methodology used to calculate commercial vehicle travel speed.