The Freight Analysis Framework modeling tool can show how truck traffic will shift regionally or nationally in response to major road closures. The tool works by removing the closed or damaged highway from the networks, and recommending alternate available routes.
During the recent flooding that affected a major freight route, I-40 in Arkansas, the FHWA used FAF to project potential freight movement changes that affected six Southeast states and analyzed where long-haul freight trucks might detour during the I-40 closure.
Knowing the changes in regional freight travel patterns in times of crisis can allow states to set up detours, prepare alternative routes to handle more traffic, and adjust signals and message signs. It can help ensure traffic continues to flow smoothly and safely for people on the highways.
FAF is the most comprehensive publicly available dataset of freight movement. It includes data on the amount and types of goods that move across land, sea and air between large metropolitan areas, states and regions. It is designed to provide comprehensive information on national level freight flows across the nation's transportation network.
The tool is available here: ops.fhwa.dot.gov