Southern California Association of Governments:

Goods movement is central to the Southern California economy, and the Southern California Association of Governments (SCAG) plays a key role in optimizing the region’s transportation system for efficient freight mobility. SCAG is the country’s largest metropolitan planning organization, representing six vast and varied counties with more than 3,700 miles of freeways and highways, 191 cities and more than 19 million residents.

As the designated Metropolitan Planning Organization (MPO) for Imperial, Los Angeles, Orange, Riverside, San Bernardino and Ventura counties, SCAG is mandated by the federal government to develop a multimodal, long-range transportation plan every four years. The plan provides a 20-year vision for investing in local transportation systems to enhance goods movement through congestion mitigation, economic efficiency and improved safety. SCAG is not an implementation organization, but it makes policy recommendations to municipal authorities based on its model outputs.

The Modeling and Forecasting Department within SCAG is charged with creating, validating and updating those models. Relying on data from a wide variety of sources, the department maintains state-of-practice models to forecast transportation conditions. These models include the Heavy-Duty Truck Model and Activity-Based Model, which use current travel behavior to predict travel patterns in the future.

SCAG’s modeling department has been seeking better aggregate origin-destination data. To gain more comprehensive insights into the nature of commercial vehicle and freight activity in the region, they used data from Geotab Intelligent Transportation Systems (ITS) Altitude platform, specifically the Origin & Destination product. Altitude is an easy-to-use, easy-to-integrate transportation analytics platform powered by deep and scalable insights for more informed decision-making. Origin & Destination enables transportation modelers and planners to understand the nuances influencing aggregate commercial vehicle journeys so they can make policy recommendations with confidence.

One of the primary purposes of SCAG’s transportation planning and policy recommendations is to promote the ongoing improvement of the goods movement system in Southern California. The importance of goods movement in the region cannot be overstated, considering it provides approximately one-third of the region’s jobs. As a leading global trade gateway to the U.S., Southern California is home to a high concentration of industries that depend on goods movement, such as manufacturing, construction, wholesale and retail trade, transportation and warehousing.

Freightworks, the SCAG Goods Movement Program, creates up-to-date information and tools to support a world-class goods movement system that relies on complex infrastructure ranging from marine ports and rail lines to local, state and interstate roads. Every four years, SCAG must also produce the Regional Transportation Plan/Sustainable Communities Strategy (RTP/SCS). It’s a massive undertaking that addresses all modes of Southern California’s transportation system, including goods movement. For every RTP cycle, SCAG must calibrate and validate the regional travel demand model based on the most recently observed, real-world data collected from a variety of sources including PeMS, Caltrans count book and Screenline count.

“No data set is perfect”, says SCAG transportation modeler Mana Sangkapichai. “We’re always working to increase the quality of input data to enhance the accuracy of our models. We’re also constantly calibrating and validating the model by comparing it with direct observations in the transportation system.”

The current Regional Transportation Plan was approved in 2020, and the plan forecasts out to 2045. With the next plan due in 2024, SCAG modelers are now busy refining the data inputs. “We’re starting to update the model and calibrate for the base year of 2019,” says Sangkapichai. “Once the base year model is validated, we can run the model for future years.”

One crucial category of data for transportation models specifies the aggregate journeys of large commercial vehicles: where they are coming from, where they’re going, how they’re traveling and why.

The rise of e-commerce in recent years and the resulting increase in delivery vehicle traffic has further complicated the task of collecting aggregate origin-destination data for the current planning cycle. “The type of delivery trucks that are called light-heavy are now having a much bigger impact on regional traffic,” he says. “This trend, along with the lack of data by vehicle weight classification, convinced us that we needed more consistent, high-quality origin-destination data for our models; data that was able to distinguish between vehicle classes.”